# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1314115271 -10800
# Node ID 0c17075080709ed5eb2eed554018dbcf2c245cf8

initial commit

diff -r 000000000000 -r 0c1707508070 .hgignore
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/.hgignore	Tue Aug 23 19:01:11 2011 +0300
@@ -0,0 +1,6 @@
+\.d$
+\.o$
+\.swp$
+^odometer.map$
+^odometer.eep$
+^odometer.hex$
diff -r 000000000000 -r 0c1707508070 Makefile
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Makefile	Tue Aug 23 19:01:11 2011 +0300
@@ -0,0 +1,38 @@
+src = $(wildcard *.c)
+obj = $(src:.c=.o)
+bin = odometer
+hex = $(bin).hex
+eep = $(bin).eep
+
+mcu_gcc = atmega168
+mcu_dude = m168
+
+CC = avr-gcc
+OBJCOPY = avr-objcopy
+
+CFLAGS = -O2 -pedantic -Wall -mmcu=$(mcu_gcc)
+LDFLAGS = -Wl,-Map,$(bin).map -mmcu=$(mcu_gcc)
+
+.PHONY: all
+all: $(hex) $(eep)
+
+$(bin): $(obj)
+	$(CC) -o $@ $(obj) $(LDFLAGS)
+
+$(hex): $(bin)
+	$(OBJCOPY) -j .text -j .data -O ihex -R .eeprom $< $@
+
+$(eep): $(bin)
+	$(OBJCOPY) -j .eeprom --change-section-lma .eeprom=0 -O ihex $< $@
+
+.PHONY: fuses
+fuses:
+	avrdude -c usbtiny -p $(mcu_dude) -U lfuse:w:0x66:m
+
+.PHONY: program
+program: $(hex)
+	avrdude -c usbtiny -p $(mcu_dude) -e -U flash:w:$(hex)
+
+.PHONY: clean
+clean:
+	rm -f $(bin) $(obj) $(hex) $(eep) $(bin).$(map)
diff -r 000000000000 -r 0c1707508070 odometer.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/odometer.c	Tue Aug 23 19:01:11 2011 +0300
@@ -0,0 +1,132 @@
+/* PORT USAGE
+ *
+ * D0-D3: data bus, connected to the D0-D3 pins of all the 4511 chips
+ * C0-C5,D4,D5: directly driving the 8 speed graph LEDs
+ * B0-B2: connected to the decoder controlling the 4511 latches as such:
+ *        000 - speed most significant
+ *        001 - speed least significant
+ *        010 - dist most significant
+ *        011 - dist middle
+ *        100 - dist least significant
+ *        101 - all latches are off (high)
+ * B3-B5: ISP. B4 also acts as generic pushbutton input
+ * B6,B7: XTAL
+ * D6,D7: comparator, hall effect sensor input and threshold trimpot.
+ */
+
+/* 16mhz resonator */
+#define F_CPU	2000000
+
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <util/delay.h>
+
+void latch(int n);
+void update_display(void);
+
+int state;
+int debug_mode = 1;
+
+unsigned long nrot;
+
+/* wheel perimeter in centimeters */
+#define WHEEL_PERIMETER		100
+
+int main(void)
+{
+	int i;
+
+	DDRB = 0xf;		/* only first four bits are outputs */
+	DDRC = 0xff;	/* speed leds 6 bits */
+	DDRD = 0xff;	/* 4bits data bus, 2 bits speed leds, 2 bits comparator (don't care) */
+
+	/* zero-out the displays and disable all pullups except for the reset pin */
+	PORTB = 0;
+	PORTC = 0x40;	/* 6th bit set, C6 is reset */
+	PORTD = 0;
+
+	for(i=0; i<5; i++) {
+		latch(i);
+	}
+
+	/* read initial comparator state */
+	state = (ACSR >> ACO) & 1;
+
+	if(debug_mode) {
+		int i, j, leds, leds_val;
+
+		for(i=0; ; i++) {
+			for(j=0; j<5; j++) {
+				/* set bits */
+				PORTD = (PORTD & 0xf0) | (((i + j) % 10) & 0xf);
+				/* latch */
+				latch(j);
+			}
+
+			leds_val = 0;
+			leds = i % 8;
+			for(j=0; j<8; j++) {
+				if(j <= leds) {
+					leds_val |= (1 << j);
+				}
+			}
+			PORTC = leds_val;
+			PORTD = (PORTD & 0xf) | ((leds_val >> 2) & (3 << 4));
+
+			_delay_ms(1000);
+		}
+	}
+
+	/* disable digital input buffer for the AINn pins */
+	/*DIDR1 = 0;*/
+
+	ACSR = (1 << ACIE);
+	/* in debug mode we want an interrupt both on rising and falling edge
+	 * to be able to blink leds when the wheel goes past. otherwise we only need
+	 * a rising edge interrupt to increment the rotation counter.
+	 */
+	if(!debug_mode) {
+		/* rising edge interrupt */
+		ACSR |= (3 << ACIS0);
+	}
+
+	sei();
+
+	for(;;);
+	return 0;
+}
+
+void latch(int n)
+{
+	unsigned char upper = PORTB & 0xf0;
+	/* pull latch low */
+	PORTB = upper | n;
+	asm volatile("nop");
+	/* pull all latches high again */
+	PORTB = upper | 5;
+}
+
+ISR(ANALOG_COMP_vect)
+{
+	if(debug_mode) {
+		int state = (ACSR >> ACO) & 1;
+
+		if(state) {
+			PORTB |= 1;
+			nrot++;
+		} else {
+			PORTB &= ~1;
+		}
+	} else {
+		nrot++;
+	}
+
+	update_display();
+}
+
+void update_display(void)
+{
+	unsigned long dist_cm = (nrot * WHEEL_PERIMETER);
+
+	/* TODO */
+}