coding for 36h straight

src: dose.c
2026-05-01 15:14:22 +02:00 · 2026-01-03 00:30:48 +01:00 · 2026-01-02 07:04:46 +01:00
32 changed files with 1425 additions and 1338 deletions
--- a/.gitignore
+++ b/.gitignore
@ -22,3 +22,6 @@ src/mul
 *.eeprom
 *.elf
 src/data
+BCH-Codes/
+*.odt
+*.userrow
--- a/src/Makefile
+++ b/src/Makefile
@ -1,19 +1,18 @@

-PROJ=bate
+PROJ=dose

 PATH:=/usr/local/bin:$(PATH)

 default: all
 all: $(PROJ).hex

-SN_bate = 1
-MCU_bate = attiny424
-C_FILES_bate = uart.c rtc.c spi.c adc.c calib.c mul.c cmd.c
-S_FILES_bate = uart_tx.S
+SN_dose = 1
+MCU_dose = attiny424
+C_FILES_dose = config.c cmd.c pwm.c uart.c base85.c bch4369.c rtc.c spi.c flash.c adc.c
+S_FILES_dose = uart_tx.S base85a.S

 MCU = $(MCU_$(PROJ))
-# When flash gets tight, use `OPT=-Os`, or use more assembler :-)
-OPT = -O2
+OPT = -Os

 CC=avr-gcc -Wall -Wno-parentheses -MMD -std=c99 $(OPT) \
  -mmcu=$(MCU) \
@ -22,8 +21,7 @@ CC=avr-gcc -Wall -Wno-parentheses -MMD -std=c99 $(OPT) \
  -fpack-struct \
  -fshort-enums \
  -mtiny-stack \
-  -mint8 \
-  -fverbose-asm
+  -mint8

 SN = $(SN_$(PROJ))
 CFLAGS = $($*_CFLAGS) $(DEBUG) -I. -DSN="$(SN)"
@ -51,41 +49,35 @@ LDFLAGS = -Teeprom.ld
 OBJCOPY = avr-objcopy

 %.hex: %.elf
-	$(OBJCOPY) -O ihex -R .eeprom -R .eemap $< $@
+	$(OBJCOPY) -O ihex -R .eeprom -R .eemap -R .userrow -R .uumap $< $@

 %.eeprom: %.elf
 	$(OBJCOPY) -O ihex -j .eemap --change-section-lma .eemap=0 $< $@

+%.userrow: %.elf
+	$(OBJCOPY) -O ihex -j .uumap --change-section-lma .uumap=0 $< $@
+

 pMCU-attiny424 = t424
-
-#
-#avrdude> dump fuses
-#>>> dump fuses 0x0 0x9
-#
-#Reading | ################################################## | 100% 0.13 s 
-#
-#0000  00 00 7e ff ff f6 ff 00  00                       |..~......       |
-#
-#avrdude> 
+pMCU-attiny824 = t824

 # WDT
-fuse0_bate= 0x00
+fuse0_dose= 0x00
 # BOD
-fuse1_bate= 0x00
+fuse1_dose= 0x00
 # OSC, 20 MHz
-fuse2_bate= 0x7e
+fuse2_dose= 0x7e
 # ???
-fuse4_bate= 0xff
+fuse4_dose= 0xff
 # SYS0 (default 0xf6)  RESET, EEPROM erase
-fuse5_bate= 0xf7
+fuse5_dose= 0xf7
 # SYS1 startup time (64ms)
-fuse6_bate= 0xff 
+fuse6_dose= 0xff 
 # APPEND
-fuse7_bate= 0x00 
+fuse7_dose= 0x00 
 # BOOTEND
-fuse8_bate= 0x00
-fuses_bate =$(patsubst %, 0x%, 00 00 7e ff ff f7 ff 00  00)
+fuse8_dose= 0x00
+fuses_dose =$(patsubst %, 0x%, 00 00 7e ff ff f7 ff 00  00)

 AVRDUDEPROG = avrdude
 AVRDUDE = $(AVRDUDEPROG)
@ -94,7 +86,7 @@ AVRDUDE_PORT = /dev/ttyUSB1

 AD = $(AVRDUDE) -p $(pMCU-$(MCU)) -P $(AVRDUDE_PORT) -c $(AVRDUDE_PROGRAMMER)

-sig_bate = 0x1e 0x92 0x2c
+sig_dose = 0x1e 0x92 0x2c

 id: $(PROJ).id
 %.id:
@ -104,12 +96,12 @@ ad: $(PROJ).ad
 %.ad:
 	$(AD) -v -t

-%.burn: %.hex
+%.burn: %.hex %.id
 	$(AD) -U flash:v:$< || $(AD) -U flash:w:$<

-%.verify: %.hex %.eeprom
+%.verify: %.hex %.eeprom %.userrow
 	-$(AD) -qq -U fuses:v:"$(fuses_$*)":m
-	-$(AD) -qq -U userrow:v:"$(BATE_CONFIG)":m
+	-$(AD) -qq -U userrow:v:$(word 3, $^)
 	-$(AD) -qq -U eeprom:v:$(word 2, $^)
 	-$(AD) -qq -U flash:v:$<

@ -119,41 +111,10 @@ fuse: $(PROJ).fuse$F
 	echo "$*: fuse$F = $(fuse$F_$*)"
 	[ -n "$(fuse$F_$*)" ] && $(AD) -B 5 -U fuse$F:w:$(fuse$F_$*):m

-# see bate.c: Configuration in USERROW
-BC_MAGIC = 0xba
-BC_VERS  = 9
-BC_TRIG  = 0x29
-BC_SEND  = 0x59
-BC_PWR   = 0xfc
-BC_TEST  = 0
-BC_SPI   = 4
-BC_MDEL  = 2
-BC_PER   = 9
-BC_CPER  = 30
-
-BC_CLK   = 1
-BC_MCLK  = 0
-BC_BAUD  = 0 0
-BC_UART  = 0xd0
-BC_PIT   = 0xff
-BC_IMM   = 5
-BC_PAD   = 0 0 0 0 0 0 0
-BC_PRE   = 0xff 0xff 0xff 0xff 0xff 0x55 0x0a 0
-
-BATE_CONFIG = $(BC_MAGIC) $(BC_VERS) \
-              $(BC_TRIG) $(BC_SEND) $(BC_PWR) $(BC_TEST) \
-              $(BC_SPI) $(BC_MDEL) $(BC_PER) $(BC_CPER) \
-              $(BC_CLK) $(BC_MCLK) $(BC_BAUD) $(BC_UART) \
-              $(BC_PIT) $(BC_IMM) $(BC_PAD) $(BC_PRE)
-
-bate.config:
-	$(AD) -U userrow:v:"$(BATE_CONFIG)":m \
-     ||	$(AD) -U userrow:w:"$(BATE_CONFIG)":m
-
 clean:
 	rm -f *.hex *.o *.s *.map *.elf *.d

-bate.hex: bate.eeprom
+# $(PROJ).hex: $(PROJ).eeprom $(PROJ).userrow

 .PHONY: eeprom.eeprom
 eeprom.eeprom:
@ -161,7 +122,3 @@ eeprom.eeprom:
 %.eeprom.burn: %.eeprom
 	$(AD) -U eeprom:v:$< || $(AD) -U eeprom:w:$< 

-calib: calib.c mul.c
-	gcc -DCALIB_DEBUG -o $@ $<
-mul: mul.c
-	gcc -DMUL_TEST -o $@ $<
--- a/src/adc.c
+++ b/src/adc.c
@ -3,9 +3,6 @@
 //

 #include "adc.h"
-#include "bate.h"
-#include "mul.h"
-#include "eeprom.h"
 #include <avr/interrupt.h>

 enum adc_conf_parameter {
@ -14,64 +11,52 @@ enum adc_conf_parameter {
 	REF =  10 << ADC_TIMEBASE_gp,
 	MODE = ADC_MODE_BURST_SCALING_gc | ADC_START_IMMEDIATE_gc,
 	MODE_DIFF = ADC_MODE_BURST_SCALING_gc | ADC_START_IMMEDIATE_gc | ADC_DIFF_bm,
-	V_RFP = ADC_MUXPOS_AIN4_gc,
-	V_NTC = ADC_MUXPOS_AIN6_gc,
-	V_BAT = ADC_MUXPOS_AIN7_gc,
+	VD1 = ADC_MUXPOS_AIN7_gc,
+	VD2 = ADC_MUXPOS_AIN10_gc,
+	VDG = ADC_MUXPOS_AIN6_gc,
 };

-struct adc_conf adc_conf[N_ADC] ADC_CONF_ADDR  = {
-	{ // Internal Temperature
-		.mode = MODE,
-		.ref  = REF | ADC_REFSEL_1024MV_gc,
-		.inp  = INP | ADC_MUXPOS_TEMPSENSE_gc,
-		.calib = 80 * 256,
-		.shifts = 1,
-	},
+__attribute__((section(".eeprom1")))
+struct adc_conf adc_conf[N_ADC]  = {
 	{ // V_CC / 10
 		.mode = MODE,
 		.ref  = REF | ADC_REFSEL_1024MV_gc,
 		.inp  = INP | ADC_MUXPOS_VDDDIV10_gc,
-		.calib = 1024 * 10,
-		.shifts = 3, // V [×10]
 	},
-	{ // Batterie Voltage / 11
+	{ // Internal Temperature
 		.mode = MODE,
 		.ref  = REF | ADC_REFSEL_1024MV_gc,
-		.inp  = INP | V_BAT,
-		.calib = 1024 * 11,
-		.shifts = 3, // V [×11]
+		.inp  = INP | ADC_MUXPOS_TEMPSENSE_gc,
 	},
-	{ // NTC biased by V_RF
-		.mode = MODE_DIFF,
+	{ // VD1
+		.mode = MODE,
 		.ref  = REF | ADC_REFSEL_1024MV_gc,
-		.inp  = INP | V_NTC,
-		.inn  = INP | V_RFP,
-		.calib = 2048 * 10,
-		.shifts = 1, // mV
+		.inp  = INP | VD1,
 	},
-	{ // NTC biased by V_RF
+	{ // VD2
+		.mode = MODE,
+		.ref  = REF | ADC_REFSEL_1024MV_gc,
+		.inp  = INP | VD2,
+	},
+	{ // VD1
 		.mode = MODE,
 		.ref  = REF | ADC_REFSEL_2500MV_gc,
-		.inp  = INP | V_NTC,
-		.calib = 2500 * 10,
-		.shifts = 1,
+		.inp  = INP | VD1,
 	},
-	{ // NTC biased by V_RF
-		.mode = MODE,
-		.ref  = REF | ADC_REFSEL_VDD_gc,
-		.inp  = INP | V_NTC,
-	},
-	{ // Transmitter power
+	{ // VD2
 		.mode = MODE,
 		.ref  = REF | ADC_REFSEL_2500MV_gc,
-		.inp  = INP | V_RFP,
-		.calib = 2500 * 10,
-		.shifts = 1,
+		.inp  = INP | VD2,
 	},
-	{ // Transmitter power
+	{ // VDG
+		.mode = MODE,
+		.ref  = REF | ADC_REFSEL_2500MV_gc,
+		.inp  = INP | VDG,
+	},
+	{ // VDG
 		.mode = MODE,
 		.ref  = REF | ADC_REFSEL_VDD_gc,
-		.inp  = INP | V_RFP,
+		.inp  = INP | VDG,
 	},
 };

@ -87,13 +72,17 @@ void start_conversion(const struct adc_conf *c)
 	ADC.COMMAND = c->mode;
 }

+#ifdef NO_EE_CONFIG
+
 void init_adc()
 {
-	PORTA.PIN4CTRL |= PORT_ISC_INPUT_DISABLE_gc;
+	PORTB.PIN1CTRL |= PORT_ISC_INPUT_DISABLE_gc;
 	PORTA.PIN6CTRL |= PORT_ISC_INPUT_DISABLE_gc;
 	PORTA.PIN7CTRL |= PORT_ISC_INPUT_DISABLE_gc;
 }

+#endif
+
 void start_adc()
 {
 	if (!adc_conf->mode)
@ -112,20 +101,18 @@ void start_adc()
 #if 0
 ISR(ADC0_RESRDY_vect)
 {
-	DEBUG_COUNTER(adc_irqs);
-
 	uint8_t i = adc_current;
 	if (i >= N_ADC)
 		goto stop;
 	adc_readings[i] = *(volatile uint16_t *) &ADC.RESULT;
-	if (++i < N_ADC) {
+	while (++i < N_ADC) {
 		const struct adc_conf *c = adc_conf + i;
-		if (c->mode || c->mode == 0xff)
-			goto stop;
-		adc_current = i;
+		if (c->mode) {
 			start_conversion(c);
+			adc_current = i;
 			return;
 		}
+	}
 stop:
 	ADC.CTRLA = 0;
 	adc_current = N_ADC;
@ -149,7 +136,7 @@ ISR(ADC0_RESRDY_vect, ISR_NAKED)
 		"push	r31"				"\n\t"
 		"lds	r24, adc_current"		"\n\t"
 		"cpi	r24, %[NADC]"			"\n\t"
-		"brsh 3f"				"\n\t"
+		"brcc 3f"				"\n\t"
 		"mov	r30, r24"			"\n\t"
 		"ldi	r31, 0"				"\n\t"
 		"lsl	r30"				"\n\t"
@ -158,22 +145,18 @@ ISR(ADC0_RESRDY_vect, ISR_NAKED)
 		"lds	r25, %[RESULT]"			"\n\t"
 		"st	Z, r25"				"\n\t"
 		"lds	r25, %[RESULT]+1"		"\n\t"
-		"std	Z+1, r25"			"\n\t"
-		"cpi	r24, %[NADC]-1"			"\n\t"
-		"brsh 3f"				"\n\t"
-		"subi	r24, 0xff"			"\n\t"
+		"std	Z+1, r25"			"\n"
+	"1:"						"\n\t"
+		"subi	r24, -1"			"\n\t"
+		"cpi	r24, %[NADC]"			"\n\t"
+		"brcc 3f"				"\n\t"
 		"mov	r30, r24"			"\n\t"
 		"ldi	r31, 0"				"\n\t"
 		"lsl	r30"				"\n\t"
 		"lsl	r30"				"\n\t"
-		"lsl	r30"				"\n\t"
+		"lsl	r30	; NADC==8!"		"\n\t"
 		"subi	r30, lo8(-(adc_conf))"		"\n\t"
-		"sbci	r31, hi8(-(adc_conf))"		"\n"
-	"1:"						"\n\t"
-		"ld	r25, Z"				"\n\t"
-		"subi	r25, 1"				"\n\t"
-		"cpi	r25, 0xfe"			"\n\t"
-		"brsh 3f"				"\n\t"
+		"sbci	r31, hi8(-(adc_conf))"		"\n\t"
 		"ldd	r25, Z+1"			"\n\t"
 		"sts	%[CTRLC], r25"			"\n\t"
 		"ldd	r25, Z+3"			"\n\t"
@ -181,6 +164,8 @@ ISR(ADC0_RESRDY_vect, ISR_NAKED)
 		"ldd	r25, Z+2"			"\n\t"
 		"sts	%[MUXPOS], r25"			"\n\t"
 		"ld	r25, Z"				"\n\t"
+		"tst	r25"				"\n\t"
+		"breq 1b"				"\n\t"
 		"sts	%[COMMAND], r25"		"\n"
 	"2:"						"\n\t"
 		"sts	adc_current, r24"		"\n\t"
@ -207,98 +192,3 @@ ISR(ADC0_RESRDY_vect, ISR_NAKED)
 		);
 }
 #endif
-
-static inline
-int16_t calib_temp(uint16_t a)
-{
-	uint16_t calib = SIGROW.TEMPSENSE0;
-	int16_t offset = (int8_t) SIGROW.TEMPSENSE1;
-	a >>= 1;
-	a -= offset << 5;
-	a = mul16sun(calib, a, 8);
-	a -= 8741;
-	// [K × 32]
-	return a;
-}
-
-// saturating addition, signed + signed
-
-static inline
-int16_t saddss(int16_t a, int16_t o)
-{
-	__asm__(
-		"	add  	%A[a], %A[o]	\n"
-		"	adc  	%B[a], %B[o]	\n"
-		"	brvc 1f			\n"
-		"	ldi  	%A[a], 0xff	\n"
-		"	ldi  	%B[a], 0x7f	\n"
-		"	brmi 1f			\n"
-		"	adiw 	%[a], 1		\n"
-		"1:				\n"
-		: [a] "+w" (a)
-		: [o] "r"  (o)
-		);
-	return a;
-}
-
-// saturating addition, unsigned + signed
-
-static inline
-uint16_t saddus(uint16_t a, int16_t o)
-{
-	__asm__(
-		"	add  	%A[a], %A[o]	\n"
-		"	adc  	%B[a], %B[o]	\n"
-		"	tst	%B[o]		\n"
-		"	brmi 1f			\n"
-		"	brcc 3f			\n"
-		"	rjmp 2f			\n"
-		"1:				\n"
-		"	brcs 3f			\n"
-		"2:				\n"
-		"	ldi  	%A[a], 0xff	\n"
-		"	ldi  	%B[a], 0xff	\n"
-		"	brcs 3f			\n"
-		"	adiw 	%[a], 1		\n"
-		"3:				\n"
-		: [a] "+w" (a)
-		: [o] "r"  (o)
-		);
-	return a;
-}
-
-void send_calib_adc(uint8_t i)
-{
-	struct adc_conf *conf = adc_conf + i;
-	uint8_t sgnd = conf->mode & ADC_DIFF_bm;
-	int16_t offset = (int16_t)conf->offset;
-	uint16_t calib = conf->calib;
-	uint16_t a = adc_readings[i];
-
-	if (conf->inp == ADC_MUXPOS_TEMPSENSE_gc) {
-		a = calib_temp(a);
-		sgnd = 1;
-	}
-
-	if (sgnd)
-		a = saddss(a, offset);
-	else
-		a = saddus(a, offset);
-
-	if (!calib) {
-		send_str(" 0x");
-		send_hex_word(a);
-		return;
-	}
-	uint16_t c;
-	if (sgnd)
-		c = calib;
-	else {
-		c = a;
-		a = calib;
-	}
-	a = mul16sun(a, c, conf->shifts >> 4);
-
-	send_char(' ');
-	send_str(decimal_str(a, conf->shifts & 3));
-}
--- a/src/adc.h
+++ b/src/adc.h
@ -10,12 +10,9 @@ struct adc_conf {
 	uint8_t ref;
 	uint8_t inp;
 	uint8_t inn;
-	int8_t offset;
-	uint8_t shifts;
-	uint16_t calib;
 };

-#define N_ADC (64/sizeof(struct adc_conf))
+#define N_ADC 8

 extern uint16_t adc_readings[N_ADC];
 extern uint8_t adc_current;
@ -24,4 +21,3 @@ void start_adc();
 void init_adc();
 static inline uint8_t adc_busy() { return ADC.STATUS & 1; }
 extern struct adc_conf adc_conf[N_ADC];
-void send_calib_adc(uint8_t i);
--- a/src/base85.c
+++ b/src/base85.c
@ -0,0 +1,43 @@
+
+#include <stdint.h>
+#include <base85.h>
+
+uint32_t divmod85(uint32_t u, uint8_t *m);
+uint32_t mul85(uint32_t u, uint8_t m);
+uint8_t base85_error;
+
+#ifdef BASE85C
+
+int base85_encode(uint32_t u, uint8_t *s)
+{
+	s += 5;
+	*s = 0;
+	u = divmod85(u, s);
+	u = divmod85(u, s);
+	u = divmod85(u, s);
+	u = divmod85(u, s);
+	*--s = (u>>24) + 33;
+	return 5;
+}
+
+const uint8_t *base85_decode(const uint8_t *s, uint32_t *u)
+{
+	uint32_t uu = 0;
+	uint8_t c;
+	for (int i=0; i<5; i++) {
+		while (1) {
+			c = *s++ - 33;
+			if (c >= 85) 
+				goto error;
+			uu = mul85(uu, c);
+			break;
+		}
+	}
+	c = 0;
+error:
+	base85_error = c;
+	*u = uu;
+	return s;
+}
+
+#endif
--- a/src/base85.h
+++ b/src/base85.h
@ -0,0 +1,4 @@
+
+extern uint8_t base85_error;
+int base85_encode(uint32_t u, uint8_t *s);
+const uint8_t *base85_decode(const uint8_t *s, uint32_t *u);
--- a/src/base85a.S
+++ b/src/base85a.S
@ -0,0 +1,148 @@
+; uint32_t divmod85(uint32_t u, uint8_t *m)
+
+				; r26/r27 = m
+				; r25 = A LSB, big endian
+				; r24 = B
+				; r23 = C
+				; r22 = D MSB
+				; r1 = undef
+
+	#ifdef BASE85C
+	.global divmod85
+divmod85:
+	movw r26, r20
+	# endif
+
+	;; ! C-ABI: gobbles r1,  m=X
+_divmod85:			; r25,r24,r23,r22 = A,B,C,D 
+	mov r18, r25
+	add r18, r24
+	clr r21
+	rol r21          	; r18,r21 = A+B
+	add r23, r18
+	clr r31
+	adc r31, r21            ; r23,r31 = A+B+C
+	add r21, r23
+	clr r18
+	adc r18, r31 		; r21,r18 = A+B>>8 + A+B+C
+	add r23, r22
+	clr r20
+	adc r31, r20		; r23,r31 = A+B+C+D
+	add r18, r23
+	adc r21, r31		; r18,r21 = A+B>>16 + A+B+C>>8 + A+B+C+D
+	sub r23, r25
+	sbc r31, r20 		; r23,r31 = B+C+D
+	add r21, r23
+	adc r20, r31 		; r18,r21,r20 = … + B+C+D<<8
+	sub r23, r24
+	clr r30
+	sbc r31, r30          	; r23,r31 = C+D
+	add r20, r23
+	adc r31, r22
+	rol r30 		; r18,r21,r20,r31,r30 = … + C+D<<16 + D<<24
+	mov r19, r18
+	movw r22, r20
+	movw r24, r30
+	lsl r19
+	rol r21
+	rol r20
+	rol r31
+	rol r30
+	add r18, r19
+	adc r25, r21 
+	adc r24, r20 
+	adc r23, r31 
+	adc r22, r30 
+	ldi r19, 85
+	mul r18, r19
+	lsl r0
+	ldi r18, 33
+	adc r1, r18
+	# ifdef BASE85C
+	st X, r1
+	clr r1
+	# else
+	st -X, r1
+	# endif
+	ret
+	
+	#ifndef	BASE85C
+	.global base85_encode
+base85_encode:
+	movw r26, r20
+	adiw r26, 5
+	st X, r1
+	rcall _divmod85
+	rcall _divmod85
+	rcall _divmod85
+	rcall _divmod85
+	subi r25, -33
+	st -X, r25
+	ldi r24, 5
+	clr r1
+	ret
+	# endif	
+
+; uint32_t mul85(uint32_t u, uint8_t m);
+
+	#ifdef BASE85C
+	.global mul85
+mul85:
+	# endif
+
+_mul85:
+	ldi r21, 85
+	mul r25, r21
+	movw r18, r0
+	mul r24, r21
+	movw r24, r0
+	mul r23, r21
+	movw r30, r0
+	mul r22, r21
+	add r18, r20
+	adc r24, r19
+	adc r30, r25
+	adc r31, r0
+	mov r25, r18
+	mov r23, r30
+	mov r22, r31
+	# ifdef BASE85C
+	clr r1
+	# endif	
+	ret
+
+	#ifndef	BASE85C
+	
+	.global base85_decode
+base85_decode:
+	push r17
+	push r22
+	push r23
+	movw r26, r24
+	clr r25
+	clr r24
+	clr r23
+	clr r22
+	ldi r17, 5
+1:	
+	ld r20, Y+
+	cpi r20, 85
+	brcc 2f
+	rcall _mul85
+	subi r17, 1
+	brne 1b
+	clr r20
+2:
+	sts base85_error, r20
+	pop r31
+	pop r30
+	st Z, r22
+	std Z+1, r23
+	std Z+2, r24
+	std Z+3, r25
+	movw r24, r26
+	pop r17
+	clr r1
+	ret
+
+	# endif
--- a/src/bch4369.c
+++ b/src/bch4369.c
@ -0,0 +1,93 @@
+/*********************************************************************
+
+galois.BCH(4369, 4369-128, extension_field=galois.GF(2**16))
+→ <BCH Code: [4369, 4241, 17] over GF(2)>
+
+hex(bch.generator_poly)
+→ '0x124a5eda5ec0cbce2104522c1782ed521'
+
+A flash page is 512 + 16 bytes.  Use the extended page size for parity
+bits.  A code size of n=4369 is achievable with m=16.  There are n-k =
+128 parity bits.  The code has a Hamming distance of d=17. That allows
+correction of up to 8 error bits.  The message is padded with 145 bits
+of zeros.
+
+*********************************************************************/
+
+
+#include "bch4369.h"
+
+uint8_t bch_parity[16];
+const
+uint8_t bch_genpoly[16] = {
+	0x24, 0xa5, 0xed, 0xa5,
+	0xec, 0x0c, 0xbc, 0xe2,
+	0x10, 0x45, 0x22, 0xc1,
+	0x78, 0x2e, 0xd5, 0x21
+};
+
+#ifdef BCH_C
+
+void bch4369(uint8_t d)
+{
+	uint8_t *p = bch_parity;
+	uint8_t m = *p;
+	for (int i=0; i<8; i++) {
+		p += 16;
+		const uint8_t *pp = bch_genpoly + 16;
+		uint8_t b = d;
+		d <<= 1;
+		uint8_t mm = m;
+		for (int j=0; j<16; j++) {
+			uint8_t bb = *--p;
+			m = bb << 1 | b >> 7;
+			if (mm & 0x80)
+				m ^= *--pp;
+			*p = m;
+			b = bb;
+		}
+	}
+}
+
+#else
+
+__attribute__ ((noinline, noclone))
+void bch4369(uint8_t d)
+{
+	__asm__ __volatile__(
+	""
+	"ldi r30, lo8(bch_parity)"	"\n\t"
+	"ldi r31, hi8(bch_parity)"	"\n\t"
+ 	"ld r25, Z"			"\n\t"
+	"bst r25, 7"			"\n\t" // copy MSB of parity → T-bit
+	"ldi r20, 8"			"\n\t" // loop r20 = 8 → 1
+   "1:"					"\n\t"
+	"adiw r30, 16"			"\n\t"
+	"ldi r26, lo8(bch_genpoly+16)"	"\n\t"
+	"ldi r27, hi8(bch_genpoly+16)"	"\n\t"
+	"rol %[D]"			"\n\t" // move next input bit → r25.7
+	"ror r25"			"\n\t"
+    "2:"				"\n\t"
+	"rol r25"			"\n\t" // Move r25.7 → C-bit 
+	"ld r25, -Z"			"\n\t" // Rotage input bit into parity byte
+	"rol r25"			"\n\t"
+	"brtc 3f"			"\n\t" // if T-bit:
+	"ld r0, -X"			"\n\t" //    xor with gen_poly
+	"eor r25, r0"			"\n\t"
+    "3:"				"\n\t"
+	"st Z, r25"			"\n\t"
+	"ror r25"			"\n\t" // save C-bit → r25.7 and MSB → r25.6
+	"cpi r30, lo8(bch_parity)"	"\n\t"
+	"brne 2b"			"\n\t"
+	"bst r25, 6"			"\n\t" // copy MSB r25.6 → T-bit
+	"subi r20, 1"			"\n\t"
+	"brne 1b"			"\n"
+	: [D] "+w" (d)
+	:
+	: "memory", "cc",
+	  "r0", "r20", "r21", "r25",
+	  "r26", "r27", "r30", "r31"
+		);
+}
+
+#endif
--- a/src/bch4369.h
+++ b/src/bch4369.h
@ -0,0 +1,6 @@
+
+#include <stdint.h>
+#include <string.h>
+extern uint8_t bch_parity[16];
+void bch4369(uint8_t d);
+static inline void bch4369_init() { memset(bch_parity, 0 , 16); }
--- a/src/calib.c
+++ b/src/calib.c
@ -1,98 +0,0 @@
-//
-// calib.c
-//
-
-// MS5534-CM.pdf
-// https://media.digikey.com/pdf/Data%20Sheets/Measurement%20Specialties%20PDFs/MS5534-CM.pdf
-
-#ifdef CALIB_DEBUG
-#    include <stdio.h>
-#    define TESTDATA_ADDR
-#else
-#    include "eeprom.h"
-#endif
-
-#include "calib.h"
-#include "mul.h"
-
-void bate_calib(const union bate *bate, struct pressure *pt)
-{
-	uint16_t C1 = bate->W1 >> 1;
-	uint16_t C5 = (bate->W1 & 1) << 13 | (bate->W2 & 0xffc0) >> 3;
-	uint8_t  C6 = bate->W2 & 0x3f;
-	uint16_t C4 = bate->W3 >> 6;
-	uint16_t C3 = bate->W4 & 0xffc0;
-	uint16_t C2 = (bate->W3 & 0x3f) << 6 | bate->W4 & 0x3f;
-
-	uint16_t D1 = bate->D1;
-	uint16_t D2 = bate->D2;
-
-	uint16_t UT1 = C5 + 20224;
-	uint16_t  dT = D2 - UT1;
-
-	uint16_t TEMPSENS = C6 + 50;
-	int16_t  TEMP = mul16sun(dT, TEMPSENS, 6) + 200;
-
-	int16_t  TCO = C4 - 512;
-	uint16_t OFFT1 = C2 << 2;
-	// fails when TCO < 0
-	uint16_t OFF = OFFT1 + mul16sun(dT, TCO, 4);
-
-	uint16_t SENST1 = C1 + 24576;
-	uint16_t TCS = C3;
-	uint16_t SENS = SENST1 + mul16sun(dT, TCS, 0);
-
-	int16_t  X = mul16sun(D1 - 7168, SENS, 2) - OFF;
-	int16_t  P = mul16sun(X, 80, 8) + 2500;
-
-	pt->T = TEMP + 2732;
-	pt->p = P;
-
-#ifdef CALIB_DEBUG
-
-	printf("W1 0x%04x\n", bate->W1);
-	printf("W2 0x%04x\n", bate->W2);
-	printf("W3 0x%04x\n", bate->W3);
-	printf("W4 0x%04x\n", bate->W4);
-	printf("D1 0x%04x %6d\n", D1, D1 - 7168);
-	printf("D2 0x%04x\n", D2);
-	printf("C1 %5u\n",     C1);
-	printf("C2 %5u\n",     C2);
-	printf("C3 %5d %5d\n", C3>>6, C3);
-	printf("C4 %5d\n",     C4);
-	printf("C5 %5u %5u\n", C5>>3, C5);
-	printf("C6 %5u\n",     C6);
-	printf("UT1 %5u\n",  UT1);
-	printf("dT        %5d\n",  dT);
-	printf("TEMPSENS  %5u\n",  TEMPSENS);
-	printf("TEMP      %5d\n",  TEMP);
-	printf("TCO       %5d\n",  TCO);
-	printf("OFFT1     %5u\n",  OFFT1);
-	printf("OFF       %5u\n",  OFF);
-	printf("SENST1    %5u\n",  SENST1);
-	printf("TCS       %5u %5u\n",  TCS>>6, TCS);
-	printf("SENS      %5u\n",  SENS);
-	printf("X         %5d\n",  X);
-	printf("P         %5d\n",  P);
-	printf(" %.1f °C %.1f mbar\n\n", TEMP/10., P/10.);
-}
-
-#define MUL_DEBUG
-#include "mul.c"
-
-int main()
-{
-	struct pressure pt;
-	for (int i=0; i<5; i++)
-		bate_calib(testdata+i, &pt);
-	return 0;
-#endif
-}
-
-const union bate testdata[] TESTDATA_ADDR = {
-	{ .w = { 0xA691, 0x0A97, 0x989F, 0xAF28, 0x4896, 0x71F4 }, },
-	{ .W = { 0xabaf, 0x3c99, 0xa31a, 0xb589}, .D = { 0x470c, 0x773f }, }, //  21.2 °C, 1021.7 mbar
-	{ .W = { 0xabaf, 0x3c99, 0xa31a, 0xb589}, .D = { 0x1a51, 0x6fed }, }, //   7.5 °C, 5.4 mbar
-	{ .W = { 0xaa3d, 0x35d9, 0xcbe5, 0xb736}, .D = { 0x4bb7, 0x7487 }, }, //  17.7 °C, 1023.0 mbar
-	{ .W = { 0xaa3d, 0x35d9, 0xcbe5, 0xb736}, .D = { 0x1e25, 0x650a }, }, // -11.3 °C, 2.4 mbar
-};
--- a/src/calib.h
+++ b/src/calib.h
@ -1,29 +0,0 @@
-
-#include <stdint.h>
-// !!! int = int8_t
-
-union bate {
-       uint8_t b[12];
-       uint16_t w[6];
-       struct {
-               uint16_t W[4];
-               uint16_t D[2];
-       };
-       struct {
-               uint16_t W1;
-               uint16_t W2;
-               uint16_t W3;
-               uint16_t W4;
-               uint16_t D1;
-               uint16_t D2;
-       };
-};
-
-struct pressure {
-	uint16_t T;
-	uint16_t p;
-};
-
-#define N_TESTDATA (64/sizeof(union bate))
-void bate_calib(const union bate *bate, struct pressure *pt);
-extern const union bate testdata[N_TESTDATA];
--- a/src/cmd.c
+++ b/src/cmd.c
@ -2,215 +2,118 @@
 // cmd.c
 //

-#include "bate.h"
-#include "rtc.h"
-#include <string.h>
+#include "cmd.h"
+#include "adc.h"
+#include "flash.h"
+#include "bch4369.h"
+#include "base85.h"
+#include "uart.h"

-#ifdef NOCMD
-// no space for this
-void parse_command(uint8_t *s, uint8_t n) {}
-#else
+void base85_send_buffer(const uint8_t *buf);
+const uint8_t *base85_fill_buffer(const uint8_t *s);
+const uint8_t *skip_space(const uint8_t *s);
+uint8_t cmd_buffer[16];
+uint8_t uart_stream_source;

-uint8_t rx_params[8];
-
-#if 0
-
-__attribute__ ((noinline, noclone))
-uint8_t parse_hex_nibble(uint8_t c)
+void parse_command(const uint8_t *s, uint8_t n)
 {
-	if (c >= '0' && c <= '9')
-		return c - '0';
-	if (c >= 'a' && c <= 'f')
-		return c - 'a' + 0x0a;
-	return 0xf0;
-}
-
-static inline
-uint8_t parse_rx_params(uint8_t *s, uint8_t n)
-{
-	uint8_t p;
-	p = 0;
-	while (n) {
-		while (n) {
-			if (*s != ' ')
-				break;
-			n--;
-			s++;
-		}
-		if (!n || p >= sizeof(rx_params))
-			break;
-		uint8_t d = parse_hex_nibble(*s);
-		if (d==0xf0)
-			break;
-		n--;
-		s++;
-		if (n) {
-			uint8_t h = 0;
-			h = parse_hex_nibble(*s);
-			if (h != 0xf0) {
-				n--;
-				s++;
-				d <<= 4;
-				d |= h;
-			}
-		}
-		rx_params[p++] = d;
-		DEBUG_POKE(rxhex, d);
-	}
-	if (!n || *s != '\n')
-		p = 0;
-	DEBUG_POKE(rxpar, p);
-	return p;
-}
-
-#else
-
-static inline
-uint8_t parse_rx_params(uint8_t *s, uint8_t n)
-{
-	uint8_t p;
-	__asm__("\n"
-		"1:					\n"
-		"	clr	%[p]			\n"
-		"	tst	%[n]			\n"
-		"	breq 8f				\n"
-		"	ldi	r26, lo8(rx_params)	\n"
-		"	ldi	r27, hi8(rx_params)	\n"
-		"2:					\n"
-		"	ld	r21, Z+			\n"
-		"	cpi	r21, ' '		\n"
-		"	breq 6f				\n"
-		"	cpi	r21, '\\n'		\n"
-		"	breq 8f				\n"
-		"	rcall	nibble			\n"
-		"	brcc 7f				\n"
-		"	mov	r25, r21		\n"
-		"	subi	%[n], 1			\n"
-		"	breq 7f				\n"
-		"	ld	r21, Z			\n"
-		"	rcall	nibble			\n"
-		"	brcc 5f				\n"
-		"	subi	%[n], 1			\n"
-		"	breq	7f			\n"
-		"	adiw	r30, 1			\n"
-		"	swap	r25			\n"
-		"	or	r25, r21		\n"
-		"5:					\n"
-		"	cpi	%[p], 8	; sz rx_params	\n"
-		"	brcc 7f				\n"
-		"	subi	%[p], -1		\n"
-		"	st	X+, r25			\n"
-#ifdef DEBUG
-		"	sts	debug_data + 6, r25	\n"
-		"	sts	debug_data + 9, %[p]	\n"
-#endif
-		"	rjmp 2b				\n"
-		"					\n"
-		"nibble:				\n"		
-		"	subi	r21, '0'		\n"
-		"	cpi	r21, 10			\n"
-		"	brcs 9f				\n"
-		"	subi	r21, 'a'-'0'		\n"
-		"	cpi	r21, 6			\n"
-		"	brcc 9f				\n"
-		"	subi	r21, -10		\n"
-		"	sec				\n"
-		"9:	ret				\n"
-		"					\n"
-		"6:					\n"
-		"	subi	%[n], 1			\n"
-		"	brne 2b				\n"
-		"7:					\n"
-		"	clr	%[p]			\n"
-		"8:					\n"
-		: [p] "=a" (p), // r24      (r16…)
-		  [s] "+z" (s), // r30,r31
-		  [n] "+a" (n)  // r22      (r16…)
-		: : "r21", "r25", "r26", "r27"
-		);
-	DEBUG_POKE(rxpar, p);
-	return p;
-}
-#endif
-
-void parse_command(uint8_t *s, uint8_t n)
-{
-	if (!n || n >= 15)
-		goto fail;
-
 	uint8_t cmd = *s++;
-	uint8_t p = parse_rx_params(s, n-1);
-	uint8_t *pp = rx_params;
-
-	uint8_t *a = (uint8_t *)(((uint16_t)pp[0] << 8) | pp[1]);
-
-	if (cmd == 'R' && p==1) 
-		__asm__("\n"
-			"	ldi	r18, 1		\n"
-			"	out	%[ccp], %[p]	\n"
-			"	sts	%[swrr], r18	\n"
-			:
-			: [p]    "r" (pp[0]),
-			  [ccp]  "n" (_SFR_IO_ADDR(CCP)),
-			  [swrr] "n" (&RSTCTRL.SWRR)
-			: "r18"
-			);
-
-	if (p >= 3 && p < 8 && (
-		    cmd == 'C' && pp[0]==0xba
-		    || cmd == 'E'
-		    || cmd == 'U')) {
-		uint8_t *e = (uint8_t*) &config;
-		if (cmd=='E')
-			e = (uint8_t*) EEPROM_START;
-		if (cmd=='U')
-			e = (uint8_t*) &USERROW;
-		e += pp[1];
-		pp[p] = *e;
-		memcpy(e, pp+2, p-2);
-		if (cmd != 'C')
-			__asm__("\n"
-				"	ldi	r24, %[erwp]	\n"
-				"	out	%[ccp], %[p]	\n"
-				"	sts	%[ctrl], r24	\n"
-				:
-				: [p]    "r" (pp[0]),
-				  [ccp]  "n" (_SFR_IO_ADDR(CCP)),
-				  [ctrl] "n" (&NVMCTRL.CTRLA),
-				  [erwp] "n" (NVMCTRL_CMD_PAGEERASEWRITE_gc)
-				: "r24"
-				);
+	if (*s =='|')
+		return;
+	s = skip_space(s);
+	uint8_t flag = *s++;
+	uint8_t r = 0;
+	send_char(cmd);
+	send_char('|');
+	if (cmd == 'A') {
+		r = adc_current;
+		if (r >= N_ADC) {
+			if (flag == '>') {
+				base85_send_buffer((void*)adc_readings);
+				flag = *s++;
 			}
-	else if (cmd == 'T' && p==1) {
-		immediate += pp[0];
-		pp[1] = immediate;
+			if (flag == '+')
+				start_adc();
 		}
-	else if (cmd == 'M' && p==2) {
-		pp[2] = *a;
 	}
-	else if (cmd == 'W' && p==3) {
-		pp[3] = *a;
-		*a = pp[2];
+	if (cmd == 'W') {
+		s = base85_fill_buffer(s);
+		r = base85_error;
 	}
-	else if (cmd == 'K' && p==4) {
-		cli();
-		pp[4] = clock_tick;
-		clock = *(uint32_t*)pp;
-		sei();
+	else if (cmd == 'B') { 
+		if (flag == '<') {
+			s = base85_fill_buffer(s);
+			flag = *s - '0';
+			if (flag < 4) {
+				s++;
+				if (!(uart_stream_source & 0xe0)) {
+					memcpy(flash_buffer+16*flag, cmd_buffer, 16);
+					uart_stream_source = flag;
 				}
-	else if (cmd == 'D' && p==1) {
-		pp[1] = test_calib;
-		test_calib = pp[0];
+				r = uart_stream_source;
+			}
+			flag = *s++;
+		}
+		r = base85_error;
+		if (!r && flag == '%') {
+			if (*s=='>')
+				base85_send_buffer(bch_parity);
+			else if (*s=='<')
+				bch4369_feed_buffer(*++s);
+			r = bch4369_feed_n;
+		}
+		else if (flag == '>') {
+			uint8_t *b = cmd_buffer;
+			flag = *s - '0';
+			if (flag < 4)
+				b = flash_buffer + 16*flag;
+			base85_send_buffer(b);
+		}
+	}
+	else if (cmd=='F') {
+		base85_fill_buffer(s);
+		r = base85_error;
+		if (!r)
+			r = flash_submit_command(cmd_buffer);
 	}
 	else
-		goto fail;
-
-	send_char('R');
-	send_char('!');
-	send_hex(cmd, pp, p+1, 1);
-	return;
-fail:
-	send_str("R?\n");
+		send_char('?');
+	send_hex_byte_eol(r);
 }

-#endif
+const uint8_t *skip_space(const uint8_t *s) {
+	while (*s == ' ')
+		s++;
+	return s;
+}
+
+const uint8_t *base85_fill_buffer(const uint8_t *s) {
+	base85_error = 0;
+	s = skip_space(s);
+	for (int i=0; !base85_error && i<FB_SIZE; i+=4)
+		s = base85_decode(s, (uint32_t *)(cmd_buffer + i));
+	s = skip_space(s);
+	return s;
+}
+
+void base85_send_buffer(const uint8_t *buf)
+{
+	uint8_t s[6];
+	for(int i=0; i<16; i++) {
+		base85_encode(buf[i], s);
+		send_str((const char *)s);
+	}
+}
+
+uint8_t bch4369_feed_n;
+
+void bch4369_feed_buffer(uint8_t flag)
+{
+	if (flag=='0') {
+		bch4369_feed_n = 0;
+		memset(bch_parity, 0, 16);
+	}
+	for (int i=0; i<16; i++)
+		bch4369(cmd_buffer[i]);
+	bch4369_feed_n++;
+}
--- a/src/cmd.h
+++ b/src/cmd.h
@ -0,0 +1,8 @@
+
+#include <stdint.h>
+
+extern uint8_t base85_error;
+extern uint8_t bch4369_feed_n;
+void parse_command(const uint8_t *s, uint8_t n);
+void bch4369_feed_buffer(uint8_t flag);
+extern uint8_t cmd_buffer[16];
--- a/src/config.c
+++ b/src/config.c
@ -0,0 +1,57 @@
+
+#include "config.h"
+
+struct_ioconf(port_config) = {
+	conf_prefix(PORTA),
+	conf_io(PORTA.PIN6CTRL, PORT_ISC_INPUT_DISABLE_gc), // AIN
+	conf_io(PORTA.PIN7CTRL, PORT_ISC_INPUT_DISABLE_gc), // AIN
+	conf_io(PORTB.PIN1CTRL, PORT_ISC_INPUT_DISABLE_gc), // AIN
+	conf_io(PORTA.OUT, Bit(SSEL_PIN)), 
+	conf_io(PORTA.DIR, Bit(SSEL_PIN) | Bit(DRAIN_PIN)
+		| Bit(MOSI_PIN) | Bit(SCK_PIN)),
+	conf_io(PORTB.OUT, 0), 
+	conf_io(PORTB.DIR, Bit(PWM_PIN)), 
+};
+
+#if 0
+
+void apply_config(const struct io_config *c, uint8_t n)
+{
+	uint8_t prefix = 0;
+	while (n--) {
+		const struct io_config *io = c++;
+		if (io->addr == 0xff)
+			prefix = io->val;
+		else {
+			uint8_t *p = (uint8_t*)((uint16_t)prefix << 8 | io->addr);
+			*p = io->val;
+		}	
+	}
+}
+
+#else
+
+__attribute__((naked))
+void apply_config(const struct io_config *c, uint8_t n)
+{
+	__asm__(
+		"movw	r30,r24"		"\n\t"
+		"clr	r24"			"\n"
+		"1:"				"\n\t"
+		"mov	r24, r27"		"\n\t"
+		"subi	r22,-1"			"\n\t"
+		"brcs 9f"			"\n"
+		"2:"				"\n\t"
+		"ld	r25, Z+"		"\n\t"
+		"ld	r24, Z+"		"\n\t"
+		"cpi	r25, 0xff"		"\n\t"
+		"breq 1b"			"\n\t"
+		"st 	X, r25"			"\n\t"
+		"subi	r22,1"			"\n\t"
+		"brcc 2b"			"\n\t"
+		"9:"				"\n\t"
+		"ret"				"\n\t"
+		);
+}
+
+#endif
--- a/src/config.h
+++ b/src/config.h
@ -0,0 +1,43 @@
+
+#ifndef _CONFIG_H
+#define _CONFIG_H
+#include <avr/io.h>
+#include <stdint.h>
+
+struct io_config {
+	uint8_t addr;
+	uint8_t val;
+};
+
+#define struct_ioconf(_n) struct io_config _n[] \
+	__attribute__((section(".eeprom9"), aligned(2)))
+
+#define conf_prefix(_io) { 0xff, (uint16_t)&(_io) >> 8 }
+#define conf_io(_io, _v) { (uint16_t)&(_io) & 0xff, (_v) }
+#define conf_ioo(_io, _o, _v) { (uint16_t)&(_io) + _o & 0xff, (_v) }
+#define conf_iow(_io, _v) conf_io(_io, (_v) & 0xff), conf_ioo(_io, 1, (_v) >> 8)
+
+void apply_config(const struct io_config *c, uint8_t n);
+
+extern struct io_config *ee9_start, *ee9_end;
+#define IO_CONFIG ee9_start
+#define IO_CONFIG_SIZE (ee9_end - ee9_start)
+
+#define Bit(x) (1<<(x))
+
+#define DRAIN_VPORT VPORTA
+#define DRAIN_PORT PORTA
+#define DRAIN_PIN  5
+#define SSEL_VPORT VPORTA
+#define SSEL_PORT PORTA
+#define SSEL_PIN 4
+#define PWM_VPORT VPORTB
+#define PWM_PORT PORTB
+#define PWM_PIN 0
+#define SPI_VPORT VPORTA
+#define SPI_PORT PORTA
+#define MOSI_PIN 1
+#define MISO_PIN 2
+#define SCK_PIN 3
+
+#endif // _CONFIG_H
--- a/src/dose.c
+++ b/src/dose.c
@ -0,0 +1,62 @@
+//
+// dose.c
+//
+
+// !!! int = int8_t
+
+#include <stdint.h>
+#include <string.h>
+
+#include <avr/interrupt.h>
+#include <avr/sleep.h>
+#include <avr/wdt.h>
+
+#include "config.h"
+#include "dose.h"
+#include "uart.h"
+#include "rtc.h"
+#include "spi.h"
+#include "cmd.h"
+#include "adc.h"
+#include "pwm.h"
+#include "flash.h"
+
+////////////////////////////////////////////////////////////////////////////////
+//
+//  Configuration in USERROW
+
+__attribute__((section(".userrow")))
+const struct config config = {
+	.magic       = USE_USERROW,
+	.version     = USE_VERSION,
+	.cpu_clk     = CLKCTRL_PDIV_2X_gc | 1, // 10MHz (max @ 3V)
+	.flash_page_size = FM_528,
+};
+
+////////////////////////////////////////////////////////////////////////////////
+//
+//  main()
+
+int main()
+{
+	while (CLKCTRL.MCLKCTRLB != config.cpu_clk) {
+		CCP = CCP_IOREG_gc;
+		CLKCTRL.MCLKCTRLB = config.cpu_clk;
+	}
+
+	set_sleep_mode(SLEEP_MODE_IDLE);
+	sleep_enable();
+	while (config.magic != USE_USERROW)
+		sleep_cpu();
+	apply_config(IO_CONFIG, IO_CONFIG_SIZE);
+
+	uint8_t reset_source = RSTCTRL.RSTFR;
+	RSTCTRL.RSTFR = reset_source;
+	send_str("\nV Turbo Dose V0.9");
+	send_hex_byte_eol(reset_source);
+
+	while (1) {
+		sleep_cpu();
+		command();
+	}
+}
--- a/src/dose.h
+++ b/src/dose.h
@ -0,0 +1,25 @@
+//
+// dose.h
+//
+
+////////////////////////////////////////////////////////////////////////////////
+//
+//  Configuration
+
+#include <stdint.h>
+#include <avr/io.h>
+
+struct config {
+	uint8_t   magic;
+	uint8_t   version;
+	uint8_t   cpu_clk;
+	uint8_t   flash_page_size;
+};
+
+enum magic_flags {
+	USE_USERROW       = 0xD0,
+	USE_VERSION       = 0x01,
+	
+};
+
+extern const struct config config;
--- a/src/eeprom.h
+++ b/src/eeprom.h
@ -1,3 +0,0 @@
-
-#define ADC_CONF_ADDR __attribute__((__section__(".eeprom")))
-#define TESTDATA_ADDR __attribute__((__section__(".eeprom")))
--- a/src/eeprom.ld
+++ b/src/eeprom.ld
@ -6,12 +6,24 @@ MEMORY
 {
    eemap   : ORIGIN =   0x1400,  LENGTH = 0x80
    eedef   : ORIGIN = 0x810000,  LENGTH = 0x80
+    uumap   : ORIGIN =   0x1300,  LENGTH = 0x20
+    uudef   : ORIGIN = 0x850000,  LENGTH = 0x20
 }
 SECTIONS
 {
    .eemap 0x1400:
    {
+	ee1_start = .;
+	*(.eeprom1)
+	ee1_end = .;
        *(.eeprom)
+	ee9_start = .;
+	*(.eeprom9)
+	ee9_end = .;
    } >eemap AT >eedef
+    .uumap 0x1300:
+    {
+        *(.userrow)
+    } >uumap AT >uudef
 }
 INSERT BEFORE .eeprom
--- a/src/flash.c
+++ b/src/flash.c
@ -0,0 +1,212 @@
+/******************************************************
+
+- opcode (hex)
+- address  
+  - pb  page and byte address
+  - xb  byte address
+  - px  page address
+  - kx  block address
+  - sx  sector address
+  - xxx don't care
+- padding
+  - 0    1 byte
+  - 00   2 bytes
+  - 0000 4 bytes
+- data
+  - …    data bytes
+  - |    no data bytes
+
+
+read commands
+
+- Main Memory Page Read                  D2 pb 0000 …
+- Continuous Array Read (Low-Power Mode) 01 pb …
+- Continuous Array Read (Low-Frequency)  03 pb …
+- Continuous Array Read (High-Frequency) 0B pb 0 …
+- Continuous Array Read (High-Frequency) 1B pb 00 …
+- Continuous Array Read (Legacy Command) E8 pb 0000 …
+- Buffer 1 Read (Low-Frequency)          D1 xb …
+- Buffer 2 Read (Low-Frequency)          D3 xb …
+- Buffer 1 Read (High-Frequency)         D4 xb 0 …
+- Buffer 2 Read (High-Frequency)         D6 xb 0 …
+
+write commands
+
+- Buffer 1 Write                         84 xb …
+- Buffer 2 Write                         87 xb …
+- Buffer 1 Page Program with Erase       83 px |
+- Buffer 2 Page Program with Erase       86 px |
+- Buffer 1 Page Program w/o  Erase       88 px |
+- Buffer 2 Page Program w/o  Erase       89 px |
+- Page through Buffer 1 with Erase       82 pb …
+- Page through Buffer 2 with Erase       85 pb …
+- Byte/Page through Buffer 1 w/o Erase   02 pb …
+- Page Erase                             81 px |
+- Block Erase                            50 kx |
+- Sector Erase                           7C sx |
+- Chip Erase                             C7_94_80_9A |
+- Program/Erase Suspend                  B0 |
+- Program/Erase Resume                   D0 |
+- Read-Modify-Write through Buffer 1     58 pbx …
+- Read-Modify-Write through Buffer 2     59 pbx …
+
+security commands
+
+- Enable Sector Protection               3D_2A_7F_A9 |
+- Disable Sector Protection              3D_2A_7F_9A |
+- Erase Sector Protection Register       3D_2A_7F_CF |
+- Program Sector Protection Register     3D_2A_7F_FC … 
+- Read Sector Protection Register        32 xxx …
+- Sector Lockdown                        3D_2A_7F_30 …
+- Read Sector Lockdown Register          35 xxx …
+- Freeze Sector Lockdown                 34_55_AA_40 |
+- Program Security Register              9B_00_00_00 …
+- Read Security Register                 77 xxx …
+
+miscellanious
+
+- Main Memory Page to Buffer 1 Transfer  53 px |
+- Main Memory Page to Buffer 2 Transfer  55 px |
+- Main Memory Page to Buffer 1 Compare   60 px |
+- Main Memory Page to Buffer 2 Compare   61 px |
+- Auto Page Rewrite through Buffer 1     58 px |
+- Auto Page Rewrite through Buffer 2     59 px |
+- Deep Power-Down                        B9 |
+- Resume from Deep Power-Down            AB |
+- Ultra-Deep Power-Down                  79 |
+- Status Register Read                   D7 …
+- Manufacturer and Device ID Read        9F …
+- “Power of 2” (Binary) Page Size        3D_2A_80_A6 |
+- Standard DataFlash Page Size           3D_2A_80_A7 |
+- Software Reset                         F0_00_00_00 |
+
+*/
+
+#include "flash.h"
+#include "cmd.h"
+
+uint8_t flash_cmd_buffer[4];
+uint8_t flash_status_bytes[2];
+uint8_t flash_buffer[FB_SIZE];
+
+uint8_t flash_cmd_na(uint16_t mode, uint16_t what)
+{
+	return flash_cmd(mode, what, 0, 0);
+}
+
+uint8_t flash_cmd(uint16_t mode, uint16_t what, uint16_t page, uint16_t byte)
+{
+	uint8_t spi_mode = SPI_FLASH | mode & FM_SPI;
+	uint8_t op = mode;
+	mode >>= 8;
+	uint8_t size = what;
+	what >>= 8;
+	uint8_t s = spi_select(spi_mode);
+	if (s)
+		return s;
+	uint8_t *b =  flash_cmd_buffer;
+	*b++ = op ;
+	switch (mode & FM_ADDR) {
+	case FM_528:
+		page <<= 1;
+	case FM_512:
+		byte |= page << 9;
+		page >>= 7;
+	case FM_SEC:
+		*b++ = page;
+		*b++ = byte>>8;
+		*b++ = byte;
+	}
+	uint8_t csize = b - flash_cmd_buffer;
+	uint8_t pads = 0;
+	switch (mode & FM_PAD) {
+	case FM_PAD4: pads = 2;
+	case FM_PAD2: pads += 1;
+	case FM_PAD1: pads += 1;
+	}
+	spi.zsize = pads;
+	if (what + size <= 64)
+		b = flash_buffer + what;
+	else if (what+size <= 80)
+		b = cmd_buffer + (what-64);
+	else if (size <= 2)
+		b = flash_status_bytes;
+	else
+		return what;
+	switch (mode & FM_START) {
+	case FM_WRITE:
+		spi_start_write(csize, flash_cmd_buffer, size, b);
+		break;
+	case FM_READ:
+		spi_start_read(csize, flash_cmd_buffer, size, b);
+		break;
+	case FM_WAIT:
+		spi.mask = 0x80;
+		spi_start_read(csize, flash_cmd_buffer, 2, b);
+		break;
+	}
+	return 0;
+}
+
+
+uint16_t flash_page, flash_block, n_blocks;
+uint8_t flash_stream_status;
+
+enum {
+	FS_IDLE  = 0,
+	FS_Rdy   = 1,
+	FS_Bsy   = 2,
+	FS_Read  = 4,
+	FS_Write = 8,
+	FS_Erase = 12,
+	FS_Buff  = 32,
+	FS_StBsy = 64,
+	FS_TxBCH = 128,
+};
+
+uint8_t flash_poll()
+{
+	uint8_t r = spi_busy_p();
+	if (r)
+		// SPI is shifting something
+		return 0x80 | r;
+	r = flash_stream_status;
+	if (r & FS_StBsy) {
+		// status bytes arrived
+		if (flash_status_bytes[0] & 0x80)
+			// flash is still busy burning
+			goto rd_status;
+		// not busy any more, move Bsy → Rdy
+		if (r & FS_Bsy)
+			r |= FS_Rdy;
+		goto rdy;
+	}
+	if (!(r & FS_Bsy))
+	    goto rdy;
+	if (r & FS_Write) {
+	rd_status:
+		// request status bytes for pending Tx od Er
+		r |= FS_StBsy;
+		flash_stream_status = r;
+		flash_cmd_na(0xd7, 0xff02);
+		return r & FS_Bsy;
+	}
+	// Rx is Rdy when SPI is idle
+rdy:
+	// clear the Bsy bits
+	r &= ~(FS_Bsy | FS_StBsy);
+	// return the ready bits
+	flash_stream_status = r;
+	return r;
+}
+
+struct flash_cmd {
+	uint16_t mode, what, page, byte;
+	uint8_t buffer[8];
+};
+
+uint8_t flash_submit_command(uint8_t *cmd)
+{
+	struct flash_cmd *c = (void*)cmd;
+	return flash_cmd(c->mode, c->what, c->page, c->byte);
+}
--- a/src/flash.h
+++ b/src/flash.h
@ -0,0 +1,24 @@
+
+#include "spi.h"
+
+enum flash_mode_bits {
+	FM_PAD1  = 0x01,
+	FM_PAD2  = 0x02,
+	FM_PAD4  = 0x03,
+	FM_PAD   = 0x03,
+	FM_512   = 0x04,
+	FM_528   = 0x08,
+	FM_SEC   = 0x0c,
+	FM_ADDR  = 0x0c,
+	FM_WRITE = 0x10,
+	FM_READ  = 0x20,
+	FM_WAIT  = 0x30,
+	FM_START = 0x30,
+	FM_CONT  = SPI_CONT,
+	FM_SPI   = FM_CONT,
+};
+
+uint8_t flash_cmd(uint16_t mode, uint16_t what, uint16_t page, uint16_t byte);
+#define FB_SIZE 64
+extern uint8_t flash_buffer[FB_SIZE];
+uint8_t flash_submit_command(uint8_t *cmd);
--- a/src/mul.c
+++ b/src/mul.c
@ -1,284 +0,0 @@
-//
-// mul.c
-//
-// To save space in ATtinys.
-// 16bit × 16bit → 16bit multiplication for AVR w/ `mul`, `muls`, `mulsu`,
-// returning the high bits, not the low bits.
-//
-// Also provides a variant for printing decimal numbers.
-
-#include "mul.h"
-
-// To save space, omit what is not needed.  Use -D when needed.
-
-#ifndef MUL_NONE
-#   define MUL16SUN
-#   define MUL_DECIMAL_STR
-#   ifdef MUL_ALL
-#       define MUL16SU
-#       define MUL16SS
-#       define MUL16UU
-#   endif
-#endif
-
-#ifdef MUL_TEST
-#define MUL_DEBUG
-#include <stdio.h>
-int main()
-{
-	int16_t tests[] = {
-		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
-		89, 99, 100, 101, 102, 0xff, 0x100, 0x101,
-		999, 1000, 1001, 9999, 10000, 10001,
-		0x7ffe, 0x7fff 
-	};
-
-	for (uint8_t dec = 0; dec < 5; dec++)
-		for (int i=0; i < sizeof(tests)/sizeof(*tests); i++) 
-			for (int s=0; s<2; s++) {
-				int16_t n = tests[i];
-				if (s)
-					n = -n;
-				printf("%u 0x%04x %+d %s\n",
-				       dec, n & 0xffff, n,
-				       decimal_str(n, dec));
-			}
-	return 0;
-}
-#endif
-
-#ifndef MUL_DEBUG
-
-#ifdef MUL16SU
-int16_t mul16su(int16_t s, uint16_t u)
-{
-	__asm__(
-		"movw  r18, %[s]"	"\n\t"
-		"mul   r18, %A[u]"	"\n\t"
-		"mov   r20, r1"		"\n\t"
-		"mulsu r19, %B[u]"	"\n\t"
-		"movw  %[s], r0"	"\n\t"
-		"mul   r18, %B[u]"	"\n\t"
-		"clr   r18"		"\n\t"
-		"add   r20, r0"		"\n\t"
-		"adc   %A[s], r1"	"\n\t"
-		"adc   %B[s], r18"	"\n\t"
-		"mulsu r19, %A[u]"	"\n\t"
-		"sbc   %B[s], r18"	"\n\t"
-		"add   r20, r0"		"\n\t"
-		"adc   %A[s], r1"	"\n\t"
-		"adc   %B[s], r18"	"\n\t"
-		"clr   r1"		"\n\t"
-		: [s] "+r" (s)
-		: [u] "a" (u)
-		: "r0", "r1", "r18", "r19", "r20"
-		);
-	return s;
-}
-#endif
-
-#ifdef MUL16SUN
-int16_t mul16sun(int16_t s, uint16_t u, uint8_t n)
-{
-	// n = 0 … 8
-	__asm__(
-		"movw  r18, %[s]"	"\n\t"
-		"mul   r18, %A[u]"	"\n\t"
-		"mov   r21, r1"		"\n\t"
-		"mulsu r19, %B[u]"	"\n\t"
-		"movw  %[s], r0"	"\n\t"
-		"mul   r18, %B[u]"	"\n\t"
-		"clr   r18"		"\n\t"
-		"add   r21, r0"		"\n\t"
-		"adc   %A[s], r1"	"\n\t"
-		"adc   %B[s], r18"	"\n\t"
-		"mulsu r19, %A[u]"	"\n\t"
-		"sbc   %B[s], r18"	"\n\t"
-		"add   r21, r0"		"\n\t"
-		"adc   %A[s], r1"	"\n\t"
-		"adc   %B[s], r18"	"\n\t"
-		"cpi   %[n], 0" 	"\n\t"
-		"breq  3f"		"\n\t"
-		"sbrs  %[n], 3"		"\n\t"
-		"rjmp  2f"		"\n\t"
-		"mov   %B[s], %A[s]"	"\n\t"
-		"mov   %A[s], r21"	"\n\t"
-		"rjmp  3f"		"\n"
-	"1:"				"\t"
-		"lsl   r21"		"\n\t"
-		"rol   %A[s]"		"\n\t"
-		"rol   %B[s]"		"\n\t"
-	"2:"				"\t"
-		"dec   %[n]"		"\n\t"
-		"brpl  1b"		"\n"
-	"3:"				"\t"
-		"clr   r1"		"\n\t"
-		: [s] "+r" (s)
-		: [u] "a" (u),
-		  [n] "r" (n)
-		: "r0", "r1", "r18", "r19", "r21"
-		);
-	return s;
-}
-#endif
-
-#ifdef MUL16SS
-int16_t mul16ss(int16_t a, int16_t b)
-{
-        // ((int32_t)a*b) >> 16
-	__asm__(
-		"movw  r18, %[a]"	"\n\t"
-		"mul   r18, %A[b]"	"\n\t"
-		"mov   r20, r1"		"\n\t"
-		"muls  r19, %B[b]"	"\n\t"
-		"movw  %[a], r0"	"\n\t"
-		"mulsu %B[b], r18"	"\n\t"
-		"clr   r18"		"\n\t"
-		"sbc   %B[a], r18"	"\n\t"
-		"add   r20, r0"		"\n\t"
-		"adc   %A[a], r1"	"\n\t"
-		"adc   %B[a], r18"	"\n\t"
-		"mulsu r19, %A[b]"	"\n\t"
-		"sbc   %B[a], r18"	"\n\t"
-		"add   r20, r0"		"\n\t"
-		"adc   %A[a], r1"	"\n\t"
-		"adc   %B[a], r18"	"\n\t"
-		"clr   r1"		"\n\t"
-		: [a] "+r" (a)
-		: [b] "a" (b)
-		: "r0", "r1", "r18", "r19", "r20"
-		);
-	return a;
-}
-#endif
-
-#ifdef MUL16UU
-int16_t mul16uu(uint16_t a, uint16_t b)
-{
-        // ((uint32_t)a*(uint32_t)b) >> 16
-	__asm__(
-		"movw  r18, %[a]"	"\n\t"
-		"mul   r18, %A[b]"	"\n\t"
-		"mov   r20, r1"		"\n\t"
-		"mul   r19, %B[b]"	"\n\t"
-		"movw  %[a], r0"	"\n\t"
-		"mul  %B[b], r18"	"\n\t"
-		"clr   r18"		"\n\t"
-		"add   r20, r0"		"\n\t"
-		"adc   %A[a], r1"	"\n\t"
-		"adc   %B[a], r18"	"\n\t"
-		"mul   r19, %A[b]"	"\n\t"
-		"add   r20, r0"		"\n\t"
-		"adc   %A[a], r1"	"\n\t"
-		"adc   %B[a], r18"	"\n\t"
-		"clr   r1"		"\n\t"
-		: [a] "+r" (a)
-		: [b] "a" (b)
-		: "r0", "r1", "r18", "r19", "r20"
-		);
-	return a;
-}
-#endif
-
-#if defined(MUL_DIVMOD10) || defined(MUL_DECIMAL_STR)
-#ifndef MUL_DIVMOD10
-static inline
-#endif
-uint16_t divmod10(uint16_t u, uint8_t *mod)
-{
-	uint16_t r;
-	uint8_t d; 
-	__asm__(
-		"ldi   r18, lo8(6554)"	"\n\t"
-		"ldi   r19, hi8(6554)"	"\n\t"
-		"mul   r18, %A[u]"	"\n\t"
-		"mov   r20, r1"		"\n\t"
-		"mul   r19, %B[u]"	"\n\t"
-		"movw  %[r], r0"	"\n\t"
-		"mul   r19, %A[u]"	"\n\t"
-		"clr   r19"		"\n\t"
-		"add   r20, r0"		"\n\t"
-		"adc   %A[r], r1"	"\n\t"
-		"adc   %B[r], r19"	"\n\t"
-		"mul   r18, %B[u]"	"\n\t"
-		"add   r20, r0"		"\n\t"
-		"adc   %A[r], r1"	"\n\t"
-		"adc   %B[r], r19"	"\n\t"
-		"ldi   r19, 10"		"\n\t"
-		"inc   r20"		"\n\t"
-		"mul   r19, r20"	"\n\t"
-		"mov   %[d], r1"	"\n\t"
-		"clr   r1"		"\n\t"
-		: [r] "=&r" (r),
-		  [d] "=r" (d)
-		: [u] "d" (u)
-		: "r0", "r1", "r18", "r19", "r20"
-		);
-	*mod = d;
-	return r;
-}
-#endif
-
-#else // MUL_DEBUG
-
-// Models for what the assembly is supposed to do.
-// Also usefull for testing in non-AVR hosts.
-
-int16_t mul16su(int16_t s, uint16_t u)
-{
-	uint32_t r = (int32_t)s * (int32_t)u;
-	return r >> 16;
-}
-int16_t mul16sun(int16_t s, uint16_t u, uint8_t n)
-{
-	// n = 0 … 8
-	uint32_t r = (int32_t)s * (int32_t)u;
-	return r >> (16-n);
-}
-int16_t mul16ss(int16_t a, int16_t b)
-{
-	uint32_t r = (int32_t)a * (int32_t)b;
-	return r >> 16;
-}
-int16_t mul16uu(uint16_t a, uint16_t b)
-{
-	uint32_t r = (int32_t)a * (int32_t)b;
-	return r >> 16;
-}
-uint16_t divmod10(uint16_t u, uint8_t *mod)
-{
-	uint32_t r = (uint32_t)u * (uint32_t)6554;
-	*mod = (((r & 0xff00)+0x100)*10) >> 16;
-	return r >> 16;
-}
-
-#endif // MUL_DEBUG
-
-#ifdef MUL_DECIMAL_STR
-static uint8_t decimals[8];
-char *decimal_str(int16_t b, uint8_t dec)
-{
-	uint8_t s = 0;
-	if (b<0) {
-		s = 1;
-		b  = -b;
-	}
-	uint8_t *c = decimals+6;
-	uint8_t n = 0;
-	while ((b || n < dec) && n<7) {
-		b = divmod10(b, c);
-		*c-- += '0';
-		if (++n==dec) {
-			*c-- = '.';
-			n++;
-		}
-	}
-	if (!n)
-		*c = '0';
-	else if (s)
-		*c = '-';
-	else
-		*c = '+';
-	return (char *)c;
-}
-#endif
--- a/src/mul.h
+++ b/src/mul.h
@ -1,15 +0,0 @@
-//
-// mul.h
-//
-
-#include <stdint.h>
-
-int16_t mul16su(int16_t s, uint16_t u);
-int16_t mul16ss(int16_t a, int16_t b);
-int16_t mul16uu(uint16_t a, uint16_t b);
-int16_t mul16sun(int16_t s, uint16_t u, uint8_t n);
-char *decimal_str(int16_t b, uint8_t dec);
-
-#if defined(MUL_DIVMOD10) || defined(MUL_ALL)
-uint16_t divmod10(uint16_t u, uint8_t *mod);
-#endif
--- a/src/pwm.c
+++ b/src/pwm.c
@ -0,0 +1,30 @@
+
+// pwm.c
+
+#include "pwm.h"
+
+#ifdef NO_EE_CONFIG
+
+void init_pwm(uint16_t period)
+{
+	PWM.CTRLA = 0;
+	PWM.CTRLB = TCA_SINGLE_CMP0EN_bm | TCA_SINGLE_WGMODE_SINGLESLOPE_gc;
+	PWM.PER   = period;
+	PWM.CMP0  = 0xffff;
+	PWM.CTRLA = 0x81;
+	D_PORT.OUT |= 1<<D_PIN;
+	D_PORT.DIR |= 1<<D_PIN;
+}
+
+#else
+
+struct_ioconf(pwm_config) = {
+	conf_prefix(PWM),
+	conf_io(PWM.CTRLA, 0),
+	conf_io(PWM.CTRLB, TCA_SINGLE_CMP0EN_bm | TCA_SINGLE_WGMODE_SINGLESLOPE_gc),
+	conf_iow(PWM.PER, 0xfff),
+	conf_iow(PWM.CMP0, 0xffff),
+	conf_io(PWM.CTRLA, 0x81),
+};
+
+#endif
--- a/src/pwm.h
+++ b/src/pwm.h
@ -0,0 +1,32 @@
+
+#include "config.h"
+
+#define PWM TCA0.SINGLE
+
+void init_pwm(uint16_t period);
+
+static inline
+void pwm_set(uint16_t dc, uint8_t d)
+{
+	PWM.CMP0 = dc;
+	if (d)
+		DRAIN_VPORT.OUT |= 1 << DRAIN_PIN;
+	else
+		DRAIN_VPORT.OUT &=~ (1 << DRAIN_PIN);
+}
+
+static inline
+void pwm_bias()
+{
+	pwm_set(0xffff, 0);
+}
+
+static inline
+void pwm_step()
+{
+	uint16_t c = PWM.CMP0+1;
+	if (c > PWM.PER+1)
+		pwm_bias();
+	else
+		pwm_set(c, 1);
+}
--- a/src/rtc.c
+++ b/src/rtc.c
@ -4,69 +4,117 @@

 // !!! int = int8_t

-#include "bate.h"
+#include "config.h"
 #include "rtc.h"

-#include <avr/io.h>
-#include <avr/interrupt.h>
-#include <avr/sleep.h>
-
 #define Bit(x) (1<<(x))

-volatile uint32_t clock;
-volatile uint8_t clock_tick;
+volatile uint16_t clock;
+volatile uint8_t pit_tick;
+volatile uint8_t rtc_tick;

-void init_rtc(uint8_t p)
-{
-	if (p>=16)
-		p = RTC_PERIOD_CYC1024_gc;
-	RTC.CLKSEL = RTC_CLKSEL_INT1K_gc;
-	RTC.PITINTCTRL = 1;
-	RTC.PITCTRLA = p;
-	while (RTC.PITSTATUS & 1) ;
-	RTC.PITCTRLA = p | 1;
-}
+struct_ioconf(rtc_config) = {
+	conf_prefix(RTC),
+	conf_iow(RTC.CMP, 3600),
+	conf_io(RTC.CLKSEL, RTC_CLKSEL_INT1K_gc),
+	conf_io(RTC.PITINTCTRL, 1),
+	conf_io(RTC.PITCTRLA, RTC_PERIOD_CYC1024_gc | RTC_PITEN_bm),
+	conf_iow(RTC.PER, 0xffff),
+	conf_io(RTC.CTRLA, RTC_PRESCALER_DIV1024_gc | RTC_RUNSTDBY_bm | RTC_RTCEN_bm),
+	conf_io(RTC.INTCTRL, RTC_CMP_bm | RTC_OVF_bm),
+};

 #if 1
+
 ISR(RTC_PIT_vect, ISR_NAKED)
 {
-	__asm__ ("push r24"            "\n\t"
-		 "in r24, __SREG__"    "\n\t"
+	__asm__ (
 		"push r24"		"\n\t"
-#ifdef DEBUG
-		 "lds r24, debug_data+9"	"\n\t"
-		 "subi r24, -1"			"\n\t"
-		 "sts debug_data+9, r24"	"\n\t"
-#endif
 		"ldi r24, 1"		"\n\t"
 		"sts %[flag], r24"	"\n\t"
-		 "sts %[tick], r24"    "\n\t"
-		 "lds r24, %[clock]"   "\n\t"
-		 "subi r24, -1"        "\n\t"
-		 "sts %[clock], r24"   "\n\t"
-		 "lds r24, %[clock]+1" "\n\t"
-		 "sbci r24, -1"        "\n\t"
-		 "sts %[clock]+1, r24" "\n\t"
-		 "lds r24, %[clock]+2" "\n\t"
-		 "sbci r24, -1"        "\n\t"
-		 "sts %[clock]+2, r24" "\n\t"
-		 "lds r24, %[clock]+3" "\n\t"
-		 "sbci r24, -1"        "\n\t"
-		 "sts %[clock]+3, r24" "\n\t"
-		 "pop r24"             "\n\t"
-		 "out __SREG__, r24"   "\n\t"
-		 "pop r24"             "\n\t"
+		"sts pit_tick, r24"	"\n\t"
+		"ldi r24, "		"\n\t"
+		"sts %[flag], r24"	"\n\t"
 		"reti"			"\n"
-		 :[tick] "+m" (clock_tick),
-		  [clock] "+m" (clock)
-		 :[flag] "n" (&RTC.PITINTFLAGS)
+		::[flag] "n" (&RTC.PITINTFLAGS)
 		);
 }
+
+ISR(RTC_CNT_vect, ISR_NAKED)
+{
+	__asm__ (
+		"push 	r24"			"\n\t"
+		"in 	r24, __SREG__"		"\n\t"
+		"push 	r24"			"\n\t"
+		"lds 	r24, %[flag]"		"\n\t"
+		"sts 	%[flag], r24"		"\n\t"
+		"sts 	rtc_tick, r24"		"\n\t"
+		"sbrs 	r24, 1"			"\n\t"
+		"rjmp 1f"			"\n\t"
+		"push 	r24"			"\n\t"
+		"push 	r25"			"\n\t"
+		"push 	r26"			"\n\t"
+		"lds 	r24, %[CMPL]"		"\n\t"
+		"lds 	r25, %[CMPH]"		"\n\t"
+		"lds 	r26, config+3"		"\n\t"
+		"add 	r24, r26"		"\n\t"
+		"sts 	%[CMPL], r24"		"\n\t"
+		"lds 	r26, config+5"		"\n\t"
+		"add 	r25, r26"		"\n\t"
+		"sts 	%[CMPH], r25"		"\n\t"
+		"pop 	r26"			"\n\t"
+		"pop 	r25"			"\n\t"
+		"pop 	r24"			"\n"
+		"1:"				"\n\t"
+		"sbrs 	r24, 0"			"\n\t"
+		"rjmp 2f"			"\n\t"
+		"lds 	r24, clock"		"\n\t"
+		"subi 	r24, -1"		"\n\t"
+		"sts 	clock, r24"		"\n\t"
+		"lds 	r24, clock+1"		"\n\t"
+		"sbci 	r24, -1"		"\n\t"
+		"sts 	clock+1, r24"		"\n\t"
+		"2:"				"\n\t"
+		"pop 	r24"			"\n\t"
+		"out 	__SREG__, r24"		"\n"
+		"pop 	r24"			"\n\t"
+		"reti"				"\n"
+		::
+		 [flag] "n" (&RTC.INTFLAGS),
+		 [CMPL] "n" (&RTC.CMP),
+		 [CMPH] "n" (&RTC.CMP+1)
+		);
+}
+
 #else
 ISR(RTC_PIT_vect)
 {
 	clock_tick = 1;
 	RTC.PITINTFLAGS = 1;
-	clock++;
+}
+ISR(RTC_CNT_vect)
+{
+	uint8_t flag = RTC.INTFLAGS;
+	RTC.INTFLAGS = flag;
+	rtc_tick = flag;
+	if (flag & RTC_CNT_bm)
+		RTC.CMP += rtc_config[1].val | rtc_config[2].val << 8;
+	if (flag & RTC_OVF_bm)
+		clock += 1;
+	return;
 }
 #endif
+
+#define NOINLINE_TICKS
+#ifdef NOINLINE_TICKS
+
+#undef time
+#undef second_tick
+#undef hour_tick
+#undef day_tick
+uint8_t time() { return timei(); }
+uint8_t second_tick() { return second_ticki(); }
+uint8_t hour_tick() { return hour_ticki(); }
+uint8_t day_tick() { return day_ticki(); }
+
+#endif
--- a/src/rtc.h
+++ b/src/rtc.h
@ -3,7 +3,53 @@
 //

 #include <stdint.h>
+#include <avr/interrupt.h>

-volatile extern uint32_t clock;
-volatile extern uint8_t clock_tick;
+volatile extern uint16_t clock;
+volatile extern uint8_t pit_tick;
+volatile extern uint8_t rtc_tick;
 void init_rtc(uint8_t p);
+
+static inline
+uint32_t timei()
+{
+	cli();
+	uint16_t c = RTC.CNT;
+	sei();
+	return c | (uint32_t)clock << 16;
+}
+
+static inline
+uint8_t second_ticki()
+{
+	cli();
+	uint8_t c = pit_tick;
+	pit_tick = 0;
+	sei();
+	return c;
+}
+
+static inline
+uint8_t hour_ticki()
+{
+	cli();
+	uint8_t c = rtc_tick;
+	rtc_tick = c & ~2;
+	sei();
+	return c & 2;
+}
+
+static inline
+uint8_t day_ticki()
+{
+	cli();
+	uint8_t c = rtc_tick;
+	rtc_tick = c & ~1;
+	sei();
+	return c & 1;
+}
+
+#define time timei
+#define second_tick second_ticki
+#define hour_tick hour_ticki
+#define day_tick day_ticki
--- a/src/spi.c
+++ b/src/spi.c
@ -2,67 +2,135 @@
 // spi.c
 //

-// !!! int = int8_t
+// ! int = int8_t

 #include "spi.h"
-#include "bate.h"
-#include <avr/interrupt.h>
-#include <avr/sleep.h>
+#include <string.h>

-volatile uint8_t spi_tick;
+struct spi_job spi;

-// The Pressure sensor samples on the rising edge, MODE = 0
-static const uint8_t SPI_Mode_Write = SPI_SSD_bm | SPI_BUFEN_bm;
+#ifdef NO_EE_CONFIG

-// The Pressure sensor delivers on the rising edge, MODE = 1
-static const uint8_t SPI_Mode_Read  = SPI_SSD_bm | SPI_BUFEN_bm | SPI_MODE_0_bm;
-
-void init_spi(uint8_t div)
+void init_spi(uint8_t spi_div)
 {
-	if (div & ~SPI_PRESC_gm)
-		div = SPI_PRESC_DIV64_gc;
-	SPI.CTRLB = SPI_Mode_Write;
-	SPI.CTRLA = SPI_MASTER_bm | SPI_ENABLE_bm | div;
+	SSEL_PORT.OUT |= 1 << SSEL_PIN;
+	SSEL_PORT.DIR |= 1 << SSEL_PIN;
+	SPI.CTRLB = SPI_SSD_bm | SPI_BUFEN_bm; // Mode 0
+	SPI.CTRLA = SPI_MASTER_bm | SPI_ENABLE_bm | spi_div;
 	SPI.DATA;
 	SPI.DATA;
 	SPI.INTFLAGS = 0xff;
-	SPI.INTCTRL = SPI_TXCIE_bm;
+	SPI.INTCTRL = 0;
 }

-uint16_t spi_frame(uint16_t d)
+#else
+
+struct_ioconf(spi_config) = {
+	conf_prefix(SPI),
+	conf_io(SPI.CTRLB, SPI_SSD_bm | SPI_BUFEN_bm),
+	conf_io(SPI.CTRLA, SPI_MASTER_bm | SPI_ENABLE_bm | SPI_SPEED),
+};
+
+#endif
+
+ISR(SPI0_INT_vect)
 {
-	if (d)
-		SPI.CTRLB = SPI_Mode_Write;
+	uint8_t ifg = SPI.INTFLAGS;
+	while (ifg & SPI_DREIF_bm) {
+		if (spi.csize) {
+			SPI.DATA = *spi.cmd++;
+			spi.csize--;
+		}
+		else if (spi.zsize) {
+			SPI.DATA = spi.zero;
+			spi.zsize--;
+		}
+		else if (spi.wsize) {
+			if (spi.wdata)
+				SPI.DATA = *spi.wdata++;
 			else
-		SPI.CTRLB = SPI_Mode_Read;
-	SPI.DATA;
-	SPI.DATA;
-	SPI.INTFLAGS = 0xff;
-	spi_tick = 0;
-	SPI.DATA = d >> 8;
-	SPI.DATA = d;
-	uint8_t timeout = 20; // 20×15µs = 300µs
-	sei();
-	while (!spi_tick) {
-		sleep_cpu();
-		if (!--timeout) {
-			DEBUG_COUNTER(spi_timeout);
+				SPI.DATA = spi.zero;
+		}
+		else {
+			if (ifg & SPI_TXCIF_bm) {
+				if (!(spi.mode & SPI_CONT))
+					SSEL_PORT.OUT |= 1 << SSEL_PIN;
+				spi.status |= SPI_IDLE;
+				SPI.INTCTRL = SPI_RXCIF_bm;
+			}
+			else {
+				SPI.INTCTRL = SPI_TXCIF_bm | SPI_RXCIF_bm;
+			}
 			break;
 		}
+		ifg = SPI.INTFLAGS;
+	}
+	while (ifg & SPI_RXCIF_bm) {
+		uint8_t d = SPI.DATA; // clears the IF flag
+		if (spi.isize)
+			spi.isize --;
+		else {
+			if (spi.mask) {
+				if ((d & spi.mask) == spi.wait) {
+					spi.zsize++;
+					SPI.INTCTRL = SPI_DREIF_bm | SPI_RXCIF_bm;
+					continue;
+				}
+				spi.mask = 0;
+			}
+			if (spi.rsize) {
+				*spi.rdata++ = d;
+				spi.rsize--;
+			}
+			else if (!spi.mask) {
+				SPI.INTCTRL = SPI_DREIF_bm;
+			}
+		}
+		ifg = SPI.INTFLAGS;
 	}
-	uint16_t b = SPI.DATA;
-	return (b<<8) | SPI.DATA;
 }

-ISR(SPI0_INT_vect, ISR_NAKED)
+uint8_t spi_select(uint8_t mode)
 {
-	__asm__ ("push r24"          "\n\t"
-		 "lds r24, %[flag]"  "\n\t"
-		 "sts %[flag], r24"  "\n\t"
-		 "sts spi_tick, r24" "\n\t"
-		 "pop r24"           "\n\t"
-		 "reti"              "\n"
-		 : : [flag] "n" (&SPI.INTFLAGS)
-		);
+	uint8_t s = spi_busy_p();
+	if (s)
+		return s;
+	memset(&spi, 0, sizeof(spi));
+	spi.mode = mode;
+	if (mode & SPI_FLASH)
+		SSEL_PORT.OUT &=~ (1 << SSEL_PIN);
+	else
+		SSEL_PORT.OUT |= 1 << SSEL_PIN;
+	if (mode & SPI_CONFIG)
+		SPI.CTRLA |= SPI_DORD_bm;
+	else
+		SPI.CTRLA &=~ SPI_DORD_bm;
+	return 0;
 }

+
+void spi_start_cmd(uint8_t csize, uint8_t *cmd)
+{
+	spi.cmd = cmd;
+	barrier();
+	spi.csize = csize;
+	spi_start();
+}
+
+void spi_start_write(uint8_t csize, uint8_t *cmd, uint8_t wsize, uint8_t *wdata)
+{
+	spi.wdata = wdata;
+	barrier();
+	spi.wsize = wsize;
+	spi_start_cmd(csize, cmd);
+}
+
+void spi_start_read(uint8_t csize, uint8_t *cmd, uint8_t rsize, uint8_t *rdata)
+{
+	spi.rdata = rdata;
+	spi.isize = csize + spi.zsize;
+	barrier();
+	spi.wsize = rsize; // more zeros
+	spi.rsize = rsize;
+	spi_start_cmd(csize, cmd);
+}
--- a/src/spi.h
+++ b/src/spi.h
@ -2,12 +2,69 @@
 // spi.h
 //

-#include <stdint.h>
-#include <avr/io.h>
+#ifndef _SPI_H
+#define _SPI_H
+
+#include "config.h"
+#include <avr/interrupt.h>

 #define SPI SPI0
+#define SPI_SPEED (SPI_CLK2X_bm | SPI_PRESC_DIV4_gc)

-extern volatile uint8_t spi_tick;
-uint16_t spi_frame(uint16_t d);
-void init_spi(uint8_t div);
-static inline void spi_off() { SPI.INTCTRL = SPI.CTRLA = 0; }
+extern
+struct spi_job {
+	uint8_t mode;
+	uint8_t status;
+	uint8_t csize;
+	uint8_t zsize;
+	uint8_t isize;
+	uint8_t rsize;
+	uint8_t wsize;
+	uint8_t zero;
+	uint8_t wait;
+	uint8_t mask;
+	const uint8_t *cmd;
+	const uint8_t *wdata;
+	uint8_t *rdata;
+} spi;
+
+enum spi_mode_bits {
+	SPI_FLASH   = 0x01,
+	SPI_CONFIG  = 0x02,
+	SPI_CONT    = 0x80,
+};
+
+enum spi_status_bits {
+	SPI_IDLE = 0x01,
+};
+
+static inline
+uint8_t spi_abort()
+{
+	cli();
+	uint8_t f = SPI.INTFLAGS;
+	SPI.INTFLAGS = 0;
+	sei();
+	return f;
+}
+
+static inline
+uint8_t spi_busy_p()
+{
+	return SPI.INTFLAGS;
+}
+
+static inline
+void  spi_start()
+{
+	SPI.INTCTRL = SPI_DREIF_bm | SPI_RXCIF_bm;	
+}
+
+static inline void barrier() { __asm__("":::"memory"); }
+void init_spi(uint8_t spi_div);
+uint8_t spi_select(uint8_t mode);
+void spi_start_cmd(uint8_t csize, uint8_t *cmd);
+void spi_start_write(uint8_t csize, uint8_t *cmd, uint8_t wsize, uint8_t *wdata);
+void spi_start_read(uint8_t csize, uint8_t *cmd, uint8_t rsize, uint8_t *rdata);
+
+#endif
--- a/src/uart.c
+++ b/src/uart.c
@ -4,99 +4,41 @@

 // !!! int = int8_t

-#include "bate.h"
-#include "mul.h"
-
-#include <avr/io.h>
+#include "uart.h"
 #include <avr/sleep.h>
 #include <avr/interrupt.h>

-#define Bit(x) (1<<(x))
-
-// 10 MHz / 2400 / 16 * 64
-#define UART_DIV 16667
-
-__attribute__ ((noinline, noclone))
-void init_uart(uint16_t div, uint8_t mode)
-{
-	if (mode==0xff)
-		mode = USART_TXEN_bm;
-	mode |= USART_TXEN_bm;
-	if (div<64)
-		div = UART_DIV;
-	USART0.BAUD = div;
-	PORTB.DIRSET = Bit(2);
-	USART0.CTRLB = mode;
-	if (mode & USART_RXEN_bm)
-		USART0.CTRLA = USART_RXCIE_bm;
-	// `BOTHEDGES` should wake from power down sleep()
-	PORTB.PIN3CTRL = PORT_PULLUPEN_bm | PORT_ISC_BOTHEDGES_gc;
-}
-
-volatile uint8_t rx_tick;
-
-ISR(PORTB_PORT_vect, ISR_NAKED)
-{
-	__asm__ ("push r24"         "\n\t"
-		 "lds r24, %[stat]" "\n\t"
-		 "sts %[stat], r24" "\n\t"
-		 "sts rx_tick, r24" "\n\t"
-		 "pop r24"          "\n\t"
-		 "reti"             "\n"
-		 : : [stat] "n" (&VPORTB.INTFLAGS)
-		);
-}
-
-__attribute__ ((noinline, noclone))
-uint8_t uart_tick()
-{
-	cli();
-	uint8_t r = rx_tick;
-	rx_tick = 0;
-	sei();
-	return r;
-}
+struct_ioconf(uart_config) = {
+	conf_prefix(USART0),
+	conf_iow(USART0.BAUD, UART_BAUD),
+	conf_io(USART0.CTRLB, UART_MODE & 0xff),
+	conf_io(USART0.CTRLC, UART_MODE >> 8),
+	conf_io(USART0.CTRLA,USART_RXCIE_bm),
+};

 // `uart_tx` buffer size must be a power of 2, max 256.
-// Fix `tx()` and `put_char()` / `put_char:`
-// when the size changes.
-// For now, we can afford half of the available RAM,
-// and still have 128 bytes for the stack
-#ifdef UART_TX_SMALL
-uint8_t uart_tx[128];
-#else
-uint8_t uart_tx[256];
-#endif
+uint8_t uart_tx[32];

 #define uart_tx_m (sizeof(uart_tx) - 1)
 volatile uint8_t uart_tx_w;
 volatile uint8_t uart_tx_r;
-volatile uint8_t uart_tx_busy;
-uint8_t uart_cks;

 #if 0

 __attribute__ ((noinline, noclone))
 void tx()
 {
-	// interrupts must be disabled
-	if (USART0.STATUS & USART_TXCIF_bm) {
-		USART0.STATUS = USART_TXCIF_bm;
-		uart_tx_busy = 0;
-	}
 	// read volatile memory once, for speed
 	uint8_t r = uart_tx_r;
 	uint8_t w = uart_tx_w;
 	while (w - r) {
-		uart_tx_busy = w - r;
 		if (!(USART0.STATUS & USART_DREIF_bm)) {
-			USART0.CTRLA |= USART_DREIE_bm | USART_TXCIE_bm;
+			USART0.CTRLA |= USART_DREIE_bm;
 			uart_tx_r = r;
 			return;
 		}
 		USART0.TXDATAL = uart_tx[r++ & uart_tx_m];
-		// race?  TXC while we were looping?  Drop it.
-		USART0.STATUS = USART_TXCIF_bm;
+		USART0.STATUS |= USART_TXCIF_bm
 	}
 	uart_tx_r = r;
 	USART0.CTRLA &=~ USART_DREIE_bm;
@ -104,7 +46,6 @@ void tx()

 ISR(USART0_DRE_vect)
 {
-	DEBUG_COUNTER(tx_irqs);
 	tx();
 }

@ -113,57 +54,43 @@ ISR(USART0_DRE_vect)
 __attribute__ ((noinline, noclone))
 void tx()
 {
-	// This uses only six registers, to save stack in the ISR.
-	// r0 and r1 need not be saved
-	// Avoids unlikely branches.
-	// [STATUS] is prepared in advance, to avoid two branches and one memory load,
-	// at the cost of one register on the ISR stack (r25)
+	// This uses only three registers, to save stack in the ISR.
 	__asm__("\n"
-		"	lds	r21, uart_tx_r				\n"
-		"	lds	r19, uart_tx_w				\n"
 		"	lds 	r25, %[CTRLA]				\n"
-		"	andi 	r25, ~0x20	; clr DREIE		\n"
-		"	lds	r30, %[STATUS]				\n"
-		"	ldi	r24, 0x40				\n"
-		"	and	r30, r24	; TXCIF			\n"
-		"	breq 2f						\n"
-		"	sts	%[STATUS], r24	; clr TXCIF		\n"
-		"	ldi	r31, 0					\n"
-		"	sts	uart_tx_busy, r31			\n"
+		"	andi 	r25, ~(1<<%[DRE])			\n"
 		"	rjmp 2f						\n"
-		"							\n"
 		"1:							\n"
-		"	mov	r30, r21	;			\n"
-		"	subi 	r21, 0xff	; r++ & uart_tx_m	\n"
-#ifdef UART_TX_SMALL
-		"	andi	r30, 0x7f	;			\n"
-#endif
-		"	ldi 	r31, 0					\n"
+		"	mov	r31, r30	;			\n"
+		"	subi 	r31, 0xff	; r++ & uart_tx_m	\n"
+		"	sts	uart_tx_r, r31 				\n"
+		"	andi	r30, 0x1f	;			\n"
+		"	clr 	r31					\n"
 		"	subi 	r30, lo8(-(uart_tx))			\n"
 		"	sbci	r31, hi8(-(uart_tx))			\n"
-		"	ld 	r24, Z					\n"
-		"	sts 	%[TXDATA], r24				\n"
-		"	ldi	r24, 0x40				\n"
-		"	sts	%[STATUS], r24	; clr TXCIF		\n"
+		"	ld 	r30, Z					\n"
+		"	sts 	%[TXDATA], r30				\n"
+		"	ldi	r30, 1<<%[TXC]				\n"
+		"	sts	%[STATUS], r30     			\n"
 		"2:							\n"
-		"	cp	r21, r19				\n"
+		"	lds	r30, uart_tx_r				\n"
+		"	lds	r31, uart_tx_w				\n"
+		"	cp	r30, r31				\n"
 		"	breq 3f						\n"
-		"	sts 	uart_tx_busy, r24	; =0x40		\n"
-		"	lds 	r24, %[STATUS]				\n"
-		"	sbrc 	r24, 5		; DREIF			\n"
+		"	lds 	r30, %[STATUS]				\n"
+		"	sbrc 	r30, %[DRE]				\n"
 		"	rjmp 1b						\n"
-		"	ori	r25, 0x60	; set DREIE TXCIE	\n"
+		"	ori	r25, 1<<%[DRE]				\n"
 		"3:							\n"		
 		"	sts 	%[CTRLA], r25				\n"
 		"	sts 	uart_tx_r, r21				\n"
 		:
-		: [STATUS] "n" (&USART0.STATUS),
+		:
+		[TXC] "n" (USART_TXCIF_bp),
+		[DRE] "n" (USART_DREIF_bp),
 		[CTRLA] "n" (&USART0.CTRLA),
+		[STATUS] "n" (&USART0.STATUS),
 		[TXDATA] "n" (&USART0.TXDATAL)
-		: "r19", "r21",
-		  "r24", "r25",
-		  "r30", "r31",
-		  "memory"
+		: "r25", "r30", "r31", "memory"
 		);
 }

@ -174,30 +101,17 @@ ISR(USART0_DRE_vect, ISR_NAKED)
 	// OTOH, the C implementation of tx() is not bad either,
 	// if we are doing this asm, then we do it agressively.
 	__asm__("\n"
-		"	push	r24				\n"
-		"	in 	r24, __SREG__			\n"
-		"	push	r24				\n"
 		"	push	r25				\n"
-		"	push	r19				\n"
-		"	push	r21				\n"
+		"	in 	r25, __SREG__			\n"
+		"	push	r25				\n"
 		"	push	r30				\n"
 		"	push	r31				\n"
-		"						\n"
-#ifdef DEBUG
-		"	lds 	r24, debug_data + 3		\n"
-		"	subi 	r24, 0xff			\n"
-		"	sts 	debug_data + 3, r24		\n"
-#endif
 		"	rcall	tx				\n"
-		"						\n"
 		"	pop	r31				\n"
 		"	pop	r30				\n"
-		"	pop	r21				\n"
-		"	pop	r19				\n"
 		"	pop	r25				\n"
-		"	pop	r24				\n"
-		"	out	__SREG__, r24			\n"
-		"	pop	r24				\n"
+		"	out	__SREG__, r25			\n"
+		"	pop	r25				\n"
 		"	reti					\n"
 		);
 }
@ -206,26 +120,28 @@ ISR(USART0_DRE_vect, ISR_NAKED)

 ISR(USART0_TXC_vect, ISR_ALIASOF(USART0_DRE_vect));

-uint8_t uart_rx[16];
+uint8_t uart_rx[32];
 #define uart_rx_m (sizeof(uart_rx) - 1)

 volatile uint8_t uart_rx_w;
+volatile uint8_t uart_rx_s;
 volatile uint8_t uart_rx_mes;
+uint8_t uart_rx_err;
+uint8_t uart_rx_errors;

 #if 0
 ISR(USART0_RXC_vect)
 {
-	DEBUG_COUNTER(rx_irqs);
-	// s/while/if/ !
 	if (USART0.STATUS & USART_RXCIF_bm) {
-		uint8_t c = USART0.RXDATAL;
-		DEBUG_POKE(rx_char, c);
+		uart_rx_s |= USART0.RXDATAH;
 		uint8_t w = uart_rx_w;
-		uart_rx[w] = c;
-		if (w < uart_rx_m)
-			uart_rx_w = ++w;
+		if (w<=uart_rx_m) {
+			uint8_t c = USART0.RXDATAL;
+			uart_rx[w++] = c;
 			if (!uart_rx_mes && c=='\n')
 				uart_rx_mes = w;
+			uart_rx_w = w;
+		}
 	}
 }
 #else
@ -246,23 +162,19 @@ ISR(USART0_RXC_vect, ISR_NAKED)
 		"	push	r24				\n"
 		"	push	r30				\n"
 		"	push	r31				\n"
-#ifdef DEBUG
-		"	lds 	r24, debug_data + 4		\n"
-		"	subi 	r24, -1				\n"
-		"	sts 	debug_data + 4, r24		\n"
-#endif
-		"	lds 	r24, %[RXDATA]	 		\n"
+		"	lds 	r24, %[DH] 			\n"
+		"	lds	r30, uart_rx_s	 		\n"
+		"	and	r24, r30			\n"
+		"	sts	uart_rx_s, r24			\n"
+		"	lds 	r24, %[DL]			\n"
 		"	lds 	r30, uart_rx_w			\n"
+		"	cpi	r30, 0x20			\n"
+		"	brcc 1f					\n"
 		"	ldi 	r31, 0		 		\n"
 		"	subi 	r30, lo8(-(uart_rx)) 		\n"
 		"	sbci 	r31, hi8(-(uart_rx)) 		\n"
 		"	st 	Z+, r24		 		\n"
-#ifdef DEBUG
-		"	sts 	debug_data + 5, r24		\n"
-#endif
 		"	subi	r30, lo8(uart_rx)		\n"
-		"	sbrc 	r30, 4 ; log2(sizeof(uart_rx))	\n"
-		"	subi	r30, 1				\n"
 		"	sts 	uart_rx_w, r30			\n"
 		"	cpi 	r24, '\n'	 		\n"
 		"	brne 1f			 		\n"
@ -277,145 +189,7 @@ ISR(USART0_RXC_vect, ISR_NAKED)
 		"	out	__SREG__, r24			\n"
 		"	pop	r24				\n"
 		"	reti					\n"
-		: : [RXDATA] "n" (&USART0.RXDATAL)
+		:: [DL] "n" (&USART0.RXDATAL), [DH] "n" (&USART0.RXDATAH)
 		);
 }
 #endif
-
-#if 0
-// These are implemented in `uart_tx.S`
-
-__attribute__ ((noinline, noclone))
-uint8_t uart_put_char(uint8_t c)
-{
-	uint8_t r = uart_tx_r;
-	uint8_t w = uart_tx_w;
-	uint8_t ww = w + 1;
-	if ((ww & uart_tx_m) == (r & uart_tx_m))
-		return 1;
-	uart_tx[w & uart_tx_m] = c;
-	__asm__("" ::: "memory");
-	uart_tx_w = ww;
-	__asm__("" ::: "memory");
-	return 0;
-}
-
-__attribute__ ((noinline, noclone))
-void send_char(uint8_t c)
-{
-	uint8_t s = 0;
-	uint8_t b;
-	while (1) {
-		b = uart_put_char(c);
-		uart_busy();
-		if (!b)
-			break;
-		sleep_cpu();
-		s = 1;
-	}
-	if (s)
-		DEBUG_COUNTER(tx_sleep);
-}
-
-__attribute__ ((noinline, noclone))
-void send_str(const char *s)
-{
-	while (*s) {
-		uint8_t c = *s++;
-		if (!uart_put_char(c))
-			continue;
-		send_char(c);
-	}
-	uart_busy();
-}
-
-static inline
-void rx_dismiss(uint8_t n)
-{
-	cli();
-	uint8_t i = 0;
-	uint8_t m = 0;
-	uint8_t w = uart_rx_w;
-	if (w != uart_rx_m)
-		while (n < w) {
-			uint8_t c = uart_rx[n++];
-			uart_rx[i++] = c;
-			if (!m && c=='\n')
-				m = i;
-		}
-	uart_rx_mes = m;
-	uart_rx_w = i;
-	sei();	
-}
-
-__attribute__ ((noinline, noclone))
-uint8_t uart_busy()
-{
-	cli();
-	tx();
-	sei();
-	return uart_tx_busy;
-}
-
-static __attribute__ ((noinline, noclone))
-void send_hex_nibble(uint8_t b)
-{
-	b += '0';
-	if (b>'9')
-		b += '@' - '9'; 
-	send_char(b);
-}
-
-__attribute__ ((noinline, noclone))
-void send_hex_byte(uint8_t b)
-{
-	send_hex_nibble(b >> 4);
-	send_hex_nibble(b & 0xf);
-}
-
-__attribute__ ((noinline, noclone))
-void send_hex_word(uint16_t b)
-{
-	send_hex_byte(b >> 8);
-	send_hex_byte(b);
-}
-
-__attribute__ ((noinline, noclone))
-void send_hex(uint8_t header, const uint8_t *s, uint8_t n, uint8_t words)
-{
-	// dump little endian words.
-	send_char(header);
-	while (n--) {
-		if (words & 1)
-			send_char(' ');
-		uint8_t l = *(s++);
-		if (words & 2 && n & 1) {
-			send_hex_byte(*(s++));
-			n--;
-		}
-		send_hex_byte(l);
-	}
-	send_char('\n');
-}
-
-void command(void)
-{
-	uint8_t m = uart_rx_mes;
-	if (!m)
-		return;
-	uint8_t *s = uart_rx;
-	uint8_t i = 0;
-	uint8_t c;
-	send_str("R ");
-	while (i++ < m) {
-		c = *s++;
-		send_char(c);
-	}
-	if (c != '\n') 
-		send_char('\n');
-	else
-		parse_command(uart_rx, m);
-	rx_dismiss(m);
-}
-
-#endif
--- a/src/uart.h
+++ b/src/uart.h
@ -2,32 +2,23 @@
 // uart.h
 //

-#include <stdint.h>
-#include <avr/io.h>
-#include <avr/sleep.h>
-#include <avr/interrupt.h>
+#include "config.h"

-void init_uart(uint16_t div, uint8_t mode);
-uint8_t uart_tick();
+#define UART_MODE 0x03c0
+#define UART_BAUD 5555 // 115200 baud

-static inline
-uint8_t uart_break_p()
-{
-	return !(VPORTB.IN & 0x08);
-}
+void init_uart(uint16_t mode, uint16_t div);

 void send_char(uint8_t c);
 void send_eol();
 void send_str(const char *s);
 void send_hex_byte(uint8_t b);
+void send_hex_byte_eol(uint8_t b);
 void send_hex_word(uint16_t b);
-void send_hex(uint8_t header, const uint8_t *s, uint8_t n, uint8_t words);
+void send_hex(const void *s, uint8_t n);
 uint8_t uart_busy();
 void command(void);
-
-void send_decimal(uint16_t b,  uint8_t dec);
-
-void parse_command(uint8_t *s, uint8_t n);
+void parse_command(const uint8_t *s, uint8_t n);

 static inline
 void send_hex_long(uint32_t b)
@ -36,5 +27,5 @@ void send_hex_long(uint32_t b)
 	send_hex_word(b);
 }

-extern uint8_t uart_cks;
-void send_cks();
+extern uint8_t uart_rx_err;
+extern uint8_t uart_rx_errors;
--- a/src/uart_tx.S
+++ b/src/uart_tx.S
@ -3,17 +3,18 @@
 //
 // avoid quite a few push and pops and jumps

+#include <avr/io.h>
+	
 	.global send_hex_word
 	.global send_hex_byte
+	.global send_hex_byte_eol
 	.global send_char
 	.global send_str
 	.global uart_busy
 	.global send_hex
-	.global send_cks
-	.global send_eol
 	.global	command

-// `tx()` and `put_char()` do not gobble r18, r20, r22, r23, r26, and r27.
+// `tx()` and `put_char()` do not gobble r18, r20, r21, r22, r24, r26, and r27.
 	
 put_char:
 	// non-global, non-C
@ -23,60 +24,64 @@ put_char:
 	ldi	r19, 1
 	add	r19, r30
 	eor	r23, r19
-#ifdef UART_TX_SMALL
-	andi	r23, 0x7f // uart_tx_m
-	breq 1f
-	andi 	r30, 0x7f // uart_tx_m
-#else
-	breq 1f
-#endif
+	andi 	r30, 0x1f // uart_tx_m
 	ldi	r31, 0
 	subi 	r30, lo8(-(uart_tx))
 	sbci 	r31, hi8(-(uart_tx))
+	andi	r23, 0x1f // uart_tx_m
+	breq 1f
 	st 	Z, r22
 	sts 	uart_tx_w, r19
-	lds	r19, uart_cks
-	add	r19, r22
-	sts	uart_cks, r19
 1:
 	// r22 preserved
 	// r23 full when zero
 	ret

-	// r18, r20, r26, and 27 must be preseved in the hex functions
-	// r22 and r23 must be preserved in `uart_busy()` and `put_char()'
+	// r18, r26, and 27 must be preseved in the hex functions
+	// …, r20, r21, r24,  must be preserved in `uart_busy()` and `put_char()'
+
+send_hex_byte_eol:
+	ldi	r22, ' '
+	rcall	send_char22
+	rcall	send_hex_byte
+send_eol:	
+	ldi	r22, '\n'
+	rcall	send_char22
+uart_busy:
+	cli
+	rcall	tx	; gobbles r25, r30, and r31
+	sei	
+	lds	r25, USART0_STATUS
+	andi	r25, SPI_TXCIF_bm
+9:
+	ret

 send_hex_word:
-	push	r24
+	mov	r20, r24
 	mov	r24, r25
 	rcall	send_hex_byte
-	pop	r24
+	mov	r24, r20
 send_hex_byte:
-	push	r24
+	mov	r21, r24
 	swap	r24
 	rcall	send_hex_nibble
-	pop	r24
+	mov	r24, r21
 send_hex_nibble:
 	andi	r24, 0x0f
 	subi 	r24, -'0'
 	cpi 	r24, '9'+1
 	brlo	send_char
 	subi	r24, '9'+1-'A'
-
 send_char:
 	mov	r22, r24
 send_char22:	
 	rcall	put_char
-	rcall	uart_busy
-	tst	r23
 	brne	9f
+	rcall	uart_busy
 	sleep
 	rjmp	send_char22

 2:
-	rcall	put_char
-	tst	r23
-	brne 1f
 	rcall	send_char22
 1:
 	movw	r24, r26
@ -85,86 +90,53 @@ send_str:
 	ld 	r22, X+
 	tst	r22
 	brne 2b
-uart_busy:
-	cli
-	rcall	tx	; gobbles only r19, r21, r24, r25, r30, and r31
-	sei	
-	lds	r24, uart_tx_busy
+send_hex:
+	movw	r26, r24
+	mov	r18, r22
+1:
+	ld	r24, X+
+	rcall	send_hex_byte
+	subi	r18, 1
+	brcc	1b
 9:
 	ret

-	; send_hex('Q', &uart_cks, 1, 0);
-send_cks:
-	ldi 	r24, 'Q'
-	ldi	r18, 0
-	ldi	r20, 1
-	ldi	r22, lo8(uart_cks)
-	ldi	r23, hi8(uart_cks)
-send_hex:
-	movw	r26, r22
-	rcall	send_char
-	rjmp	3f
-
-1:
-	ldi	r22, ' '
-	sbrc	r18, 0
-	rcall	send_char22
-	ld	r24, X+
-	sbrs	r18, 1
-	rjmp 2f
-	sbrs	r20, 0
-	rjmp 2f
-	push	r24
-	subi	r20, 1
-	ld	r24, X+
-	rcall	send_hex_byte
-	pop	r24
-2:	
-	rcall	send_hex_byte
-3:	
-	subi	r20, 1
-	brcc	1b
-send_eol:
-	ldi	r22, 10
-	rjmp	send_char22
-
 command:
-	lds	r20, uart_rx_mes
-	tst	r20
-	breq 9b
-	ldi	r22, 'R'
-	rcall	send_char22
-	ldi	r22, '>'
-	rcall	send_char22
-	ldi	r26, lo8(uart_rx)
-	ldi	r27, hi8(uart_rx)
-	mov	r18, r20
-1:
-	ld	r22, X+
-	rcall	send_char22
-	subi	r18, 1
-	brne	1b
+	;; when any frame errors occured, dismiss the buffer
+	lds	r22, uart_rx_s
+	andi	r22, 0x46
+	brne uart_errs_p
+	;; when there is no message, check for overflow
+	lds	r22, uart_rx_mes
+	tst	r22
+	breq uart_full_p
+	;; when the buffer was dismissed for errors, skip this command
+	push	r22
+	lds	r24, uart_rx_err
+	sts	uart_rx_err, r1
+	lds	r25, uart_rx_errors
+	or 	r25, r24
+	sts	uart_rx_errors, r25
+	tst	r24
+	brne 2f
 	ldi	r24, lo8(uart_rx)
 	ldi	r25, hi8(uart_rx)
-	mov	r22, r20
-	push	r20
 	rcall	parse_command
+2:
 	pop	r24
 rx_dismiss:
 	cli
 	lds	r18, uart_rx_w
 	clr	r19
 	clr	r20
-	cpi	r18, 15
-	brcc 3f
 	sub	r18, r24
 	breq 3f
-	brcs 3f // TCNH, n > w
+	brcs 3f
 	ldi	r26, lo8(uart_rx)
 	ldi	r27, hi8(uart_rx)
 	movw	r30, r26
 	add	r30, r24
-	adc	r31, r1
+	adc	r31, r20
 1:	
 	ld	r25, Z+
 	st	X+, r25
@ -175,7 +147,7 @@ rx_dismiss:
 	brne 2f
 	mov	r20, r19
 2:	
-	cp	r19, r18
+	subi	r18, 1
 	brne	1b
 3:
 	sts	uart_rx_mes, r20
@ -183,3 +155,15 @@ rx_dismiss:
 	sei
 9:
 	ret
+
+uart_full_p:
+	lds	r22, uart_rx_w
+	andi 	r22, 0x20
+	breq 9b
+uart_errs_p:
+	lds	r24, uart_rx_err
+	or	r24, r22
+rx_dismiss_buffer:
+	sts	uart_rx_err, r24
+	lds	r24, uart_rx_w
+	rjmp rx_dismiss
Author	SHA1	Message	Date
Stephan I. Böttcher	46809f6fac	coding for 36h straight	2026-01-03 00:30:48 +01:00
Stephan I. Böttcher	bf73d2b586	src: dose.c	2026-01-02 07:04:46 +01:00