scoutos / scout_avr / bom / bom.c @ f572eaeb
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#include <stdint.h> |
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#include <avr/io.h> |
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#include <avr/interrupt.h> |
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#include <util/delay.h> |
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#include "twi.h" |
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#include "bomi2c.h" |
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#define QUEUE_SIZE 64 |
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uint16_t queue[QUEUE_SIZE]; |
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int queue_idx;
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char last_bit;
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char count;
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uint16_t data; |
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#define READ_BIT(pin, bit) (((pin) >> bit) & 1) |
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#define SET_BIT(pin, bit) ((pin) |= (1 << (bit))) |
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#define RESET_BIT(pin, bit) ((pin) &= ~(1 << (bit))) |
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static void send_bit(char bit); |
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static void slave_tx(void) { |
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twi_transmit((uint8_t*)queue, queue_idx * sizeof(queue[0])); |
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queue_idx = 0;
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} |
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static void slave_rx(uint8_t *buf, int len) { |
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if (len > 0) { |
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switch (buf[0]) { |
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case BOM_I2C_SEND:
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// TODO
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break;
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} |
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} |
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} |
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static void bom_start(void) { |
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data = 0;
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count = 0;
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last_bit = 1;
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// TODO disable interrupt
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// TODO start timer
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} |
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static void bom_stop(void) { |
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// TODO stop timer
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// TODO restart INT0
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} |
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static void bom_init(void) { |
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// setup INT0
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//EICRA |= _BV(ISC01) | _BV(ISC00);
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//EIMSK |= _BV(INT0);
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// setup timer 0
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//TCCR0B |= _BV(CS01);
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// setup output pin
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SET_BIT(DDRD, 5);
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//sei();
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bom_start(); |
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} |
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ISR(TIMER0_COMPA_vect) { |
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char this_bit = READ_BIT(PIND, PD2);
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if (this_bit == 0) { |
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if (last_bit == 0) { |
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bom_stop(); |
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} |
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} else {
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data = data << 1 | (~last_bit & 1); |
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count++; |
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} |
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last_bit = this_bit; |
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if (count == 15) { |
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if (queue_idx < QUEUE_SIZE) {
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queue[queue_idx] = data; |
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queue_idx++; |
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} |
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bom_stop(); |
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} |
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} |
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static void send_data(uint16_t data) { |
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for (int i = 14; i >= 0; i--) { |
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send_bit((data >> i) & 1);
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} |
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send_bit(0);
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} |
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static void send_bit(char bit) { |
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SET_BIT(PORTD, PD5); |
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_delay_us(320);
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RESET_BIT(PORTD, PD5); |
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if (bit) {
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_delay_us(1680);
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} else {
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_delay_us(680);
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} |
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} |
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int main() {
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bom_init(); |
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for (;;) {
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send_data(45243);
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_delay_ms(100);
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} |
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} |
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ISR(INT0_vect) { |
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bom_start(); |
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} |