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authorSebastian Reichel <sre@ring0.de>2012-08-11 23:02:47 +0200
committerSebastian Reichel <sre@ring0.de>2012-08-11 23:02:47 +0200
commit2b427f4bdfc71b055b7db8ffe2b9dd0ea3e4cc9a (patch)
treef67684ceafcdccd777cc3e1684ca72b63096be1b /firmware
downloadatmostripe-master.tar.bz2
initial commitHEADmaster
Diffstat (limited to 'firmware')
-rw-r--r--firmware/Makefile32
-rw-r--r--firmware/firmware.c170
2 files changed, 202 insertions, 0 deletions
diff --git a/firmware/Makefile b/firmware/Makefile
new file mode 100644
index 0000000..d9b89e7
--- /dev/null
+++ b/firmware/Makefile
@@ -0,0 +1,32 @@
+SOURCES := firmware.c
+OBJECTS := $(patsubst %.c, %.o, $(SOURCES))
+CFLAGS := -O2 -std=c99 -mmcu=atmega48 -Wall -DF_CPU=16000000UL -DDEBUG=1
+LDFLAGS := -mmcu=atmega48 -lm
+
+all: fw.hex
+
+%.o: %.c
+ @echo "[CC] $<"
+ @avr-gcc -o $@ $(CFLAGS) -c $<
+
+fw.hex: fw.elf
+ @echo "[HEX] $@"
+ @avr-objcopy $^ -O ihex -R .eeprom $@
+
+fw.elf: ${OBJECTS}
+ @echo "[LD] $@"
+ @avr-gcc -o $@ $(LDFLAGS) $^
+
+fw.S: fw.elf
+ @avr-objdump -d fw.elf -h -m avr > fw.S
+
+clean:
+ @rm -f ${OBJECTS} fw.hex fw.elf fw.S
+
+backup:
+ avrdude -c buspirate -P /dev/ttyUSB0 -p m48 -U flash:r:"backup.hex":i noreset
+
+flash:
+ avrdude -c buspirate -P /dev/ttyUSB0 -p m48 -U flash:w:"fw.hex":i reset
+
+.PHONY: all clean backup flash
diff --git a/firmware/firmware.c b/firmware/firmware.c
new file mode 100644
index 0000000..9a04d41
--- /dev/null
+++ b/firmware/firmware.c
@@ -0,0 +1,170 @@
+#include <avr/io.h>
+#include <util/delay.h>
+#include <util/delay.h>
+#include <avr/interrupt.h>
+
+/* 500Hz -> 2ms */
+#define MAXPULSFREQ 500
+
+/* timer1 value for a 2ms puls */
+#define TIMER_MAXPULS F_CPU/MAXPULSFREQ
+
+/* min/max values */
+#define MINPULS 13500
+#define MAXPULS 30000
+
+/* baud rate for serial communication */
+#define BAUD 9600UL
+
+/* hardware settings for baud rate */
+#define UBRR_VAL ((F_CPU+BAUD*8)/(BAUD*16)-1)
+#define BAUD_REAL (F_CPU/(16*(UBRR_VAL+1)))
+#define BAUD_ERROR ((BAUD_REAL*1000)/BAUD)
+
+/* compile time check if baud rate is ok */
+#if ((BAUD_ERROR<990) || (BAUD_ERROR>1010))
+ #error systematic error of baud rate is > 1%
+#endif
+
+
+static uint16_t servo_pulslength[20];
+static uint8_t activated = 0;
+
+/* init IO pins */
+static inline void init_io() {
+ /* PB1 = left:red, PB2 = left:green, PB3 = left:blue */
+ DDRB = (1 << PB1) | (1 << PB2) | (1 << PB3);
+
+ /* PD3 = right:red, PD5 = right:green, PD6 = right:blue */
+ DDRD = (1 << PD3) | (1 << PD5) | (1 << PD6);
+
+ /* These pins are broken, so enable them */
+ DDRC = (1 << PC4) | (1 << PC5) | (1 << PC6);
+ PORTC = (1 << PC4) | (1 << PC5) | (1 << PC6);
+}
+
+/* INTERRUPT: timer for software pwm to control servos */
+ISR(TIMER1_OVF_vect) {
+ static uint8_t servo_indexhalf = 0;
+
+ switch(servo_indexhalf) {
+ case 0 : PORTB |= (1 << PB1); break;
+ case 1 : PORTB &= ~(1 << PB1); break;
+ case 2 : PORTB |= (1 << PB2); break;
+ case 3 : PORTB &= ~(1 << PB2); break;
+ case 4 : PORTB |= (1 << PB3); break;
+ case 5 : PORTB &= ~(1 << PB3); break;
+ case 6 : PORTD |= (1 << PD3); break;
+ case 7 : PORTD &= ~(1 << PD3); break;
+ case 8 : PORTD |= (1 << PD5); break;
+ case 9 : PORTD &= ~(1 << PD5); break;
+ case 10: PORTD |= (1 << PD6); break;
+ case 11: PORTD &= ~(1 << PD6); break;
+ }
+
+ /* set time for the next interrupt */
+ TCNT1 = servo_pulslength[servo_indexhalf];
+
+ servo_indexhalf++;
+
+ if(servo_indexhalf == 20)
+ servo_indexhalf = 0;
+}
+
+/* setup serial communication */
+static inline void init_uart() {
+ UBRR0 = UBRR_VAL;
+ UCSR0B |= (1 << TXEN0);
+ UCSR0B |= (1 << RXEN0);
+
+ /* Frame Format: Asynchron 8N1 */
+ UCSR0C = (1<<UCSZ01)|(1<<UCSZ00);
+}
+
+/* set servo speed */
+static inline void servo_set(uint8_t index, uint8_t value) {
+ if(!activated)
+ value = 0;
+
+ if (index < 6) {
+ uint16_t tmp = MINPULS+(MAXPULS-MINPULS)/256*value;
+ /* calculate hightime */
+ servo_pulslength[index<<1]=(-1)*tmp;
+ /* sum of low and hightime for one servo is 2ms */
+ servo_pulslength[(index<<1)+1] = (-1)*(TIMER_MAXPULS-tmp);
+ }
+}
+
+/* init servos, reset speed */
+static inline void init_servo() {
+ uint8_t i;
+
+ /* disable all motors */
+ for(i=0;i<6;i++)
+ servo_set(i, 0);
+
+ /* init timer */
+ TCNT1 = 0 - 16000;
+ TCCR1A = 0;
+ TCCR1B = (1 << CS10);
+ TIMSK1 |= (1 << TOIE1);
+}
+
+/* get a single byte from serial device */
+static inline uint8_t uart_getc() {
+ while (!(UCSR0A & (1<<RXC0)));
+ return UDR0;
+}
+
+/* put a single byte to serial device */
+static inline void uart_putc(uint8_t c) {
+ while (!(UCSR0A & (1<<UDRE0)));
+ UDR0 = c;
+}
+
+int main() {
+ /* initialize hardware */
+ init_io();
+ init_servo();
+ init_uart();
+ sei();
+
+ uint8_t c;
+
+ while(1) {
+ c = uart_getc();
+
+ /* set speed for single engine */
+ if(c >= 0x01 && c <= 0x06) {
+ uint8_t speed = uart_getc();
+ servo_set(c-1, speed);
+ /* set speed for all engines */
+ } else if(c == 0xFF) {
+ uint8_t speed = uart_getc();
+ for(int i=0;i<6;i++)
+ servo_set(i, speed);
+ /* activate engines */
+ } else if(c == 0xCA) {
+ if(uart_getc() != 0xFE) continue;
+ if(uart_getc() != 0xBA) continue;
+ if(uart_getc() != 0xBE) continue;
+ activated=1;
+ /* disable engines */
+ } else if(c == 0xDE) {
+ if(uart_getc() != 0xAD) continue;
+ if(uart_getc() != 0xBA) continue;
+ if(uart_getc() != 0xBE) continue;
+ activated=0;
+ for(int i=0;i<6;i++)
+ servo_set(i, 0);
+ /* ignore unknown commands */
+ } else if(c != 0x00) {
+ continue;
+ }
+
+ /* acknowledge command */
+ uart_putc('.');
+ }
+
+ return 0;
+}