diff options
Diffstat (limited to 'firmware')
| -rw-r--r-- | firmware/Makefile | 32 | ||||
| -rw-r--r-- | firmware/firmware.c | 170 |
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; +} |