Revision b2554c5c
Begin cleaning up bom code
| scout_avr/bom/bom.c | ||
|---|---|---|
| 18 | 18 |
#define TIME_US(us) (F_CPU * (us) / 1000000 / PRESCALAR) |
| 19 | 19 |
|
| 20 | 20 |
#define ADDRESS 0x3 |
| 21 |
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| 22 |
static void bom_start(void) {
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data = 0; |
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| 24 |
count = 0; |
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| 25 |
last_bit = 1; |
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| 26 |
// TODO disable interrupt |
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| 27 |
// TODO start timer0 |
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| 28 |
} |
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| 29 |
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| 30 |
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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| 21 |
#define DETECT PB2 |
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| 22 |
#define EMIT PB4 |
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| 34 | 23 |
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| 35 | 24 |
static void bom_init(void) {
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| 36 | 25 |
|
| ... | ... | |
| 38 | 27 |
//EICRA |= _BV(ISC01) | _BV(ISC00); |
| 39 | 28 |
//EIMSK |= _BV(INT0); |
| 40 | 29 |
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| 41 |
// setup timer 0 |
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| 42 |
TCCR0B |= _BV(CS01); |
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| 43 |
TIMSK |= _BV(OCIE0A); |
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| 30 |
init_timer0(); |
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| 31 |
start_timer0(); |
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| 44 | 32 |
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// setup timer 1 for output |
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OCR1B = TIME_US(320); // Set match b to fire every 320 us |
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| 47 |
TIMSK |= _BV(OCIE1A) | _BV(OCIE1B); // Enable interrupt for match a and b |
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| 48 |
TCCR1 |= _BV(CTC1); // Enables resetting timer1 after matches match c |
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| 33 |
init_timer1(); |
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| 49 | 34 |
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| 50 | 35 |
// setup output pin |
| 51 | 36 |
SET_BIT(DDRB, 4); |
| ... | ... | |
| 54 | 39 |
bom_start(); |
| 55 | 40 |
} |
| 56 | 41 |
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| 42 |
////////////////////////////////// Receiving /////////////////////////////////// |
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static void init_timer0(void) {
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TCCROA |= _BV(WGM01); // enable reset on compare A |
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TIMSK |= _BV(OCIE0A); // enable timer0 compare match A |
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} |
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| 48 |
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| 49 |
static void start_timer0(void) {
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TCNT0 = 0; // Reset timer 0 count to 0 |
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TCCR0B |= _BV(CS01); // setup clkio and start the timer |
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} |
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| 53 |
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| 54 |
static void start_detect(void) {
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data = 0; |
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count = 0; |
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last_bit = 1; |
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start_timer0(); |
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} |
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static void stop_detect(void) {
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TCCR0B &= ~0x07; // Stop timer0 |
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} |
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| 57 | 65 |
ISR(TIMER0_COMPA_vect) {
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| 58 | 66 |
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| 59 |
char this_bit = READ_BIT(PINB, PB2);
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| 67 |
char this_bit = READ_BIT(PINB, DETECT);
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| 60 | 68 |
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| 61 | 69 |
if (this_bit == 0) {
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| 62 | 70 |
if (last_bit == 0) {
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bom_stop();
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stop_detect();
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| 64 | 72 |
} |
| 65 | 73 |
} else {
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| 66 | 74 |
data = data << 1 | (~last_bit & 1); |
| ... | ... | |
| 70 | 78 |
last_bit = this_bit; |
| 71 | 79 |
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| 72 | 80 |
if (count == 15) {
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stop_detect(); |
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| 73 | 82 |
smb_send_data(&data, sizeof(data)); |
| 74 |
bom_stop(); |
|
| 75 | 83 |
} |
| 76 | 84 |
} |
| 77 | 85 |
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| 86 |
//////////////////////////////////////////////////////////////////////////////// |
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//////////////////////////////////// Sending /////////////////////////////////// |
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static void start_timer1() {
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TCNT1 = 0; // Reset timer 1 count to 0 |
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TCCR1 |= _BV(CS12) // Set prescalar to 8 and start timer1 |
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} |
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static void stop_timer1() {
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TCCR1 &= ~0x0F; // Stop the timer without clearing CTC1 |
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} |
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| 98 |
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| 99 |
static void init_timer1() {
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OCR1B = TIME_US(320); // Set match b to fire every 320 us |
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TIMSK |= _BV(OCIE1A) | _BV(OCIE1B); // Enable interrupt for match a and b |
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TCCR1 |= _BV(CTC1); // Enables resetting timer1 after matches match c |
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} |
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| 104 |
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static void send_data(uint16_t data) {
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sending_data = data; |
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sending_counter = 0; |
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| 108 |
currently_sending = 1; |
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SET_BIT(PORTB, EMIT); |
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| 110 |
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start_timer1(); |
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send_next_bit(); |
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} |
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| 78 | 115 |
static void send_next_bit() {
|
| 79 | 116 |
char next_bit = sending_data >> (14 - sending_counter) & 1; |
| 80 | 117 |
char ocr_temp = next_bit ? TIME_US(2000-40) : TIME_US(1000-20); |
| 81 |
OCR1A = ocr_temp; |
|
| 82 |
OCR1C = ocr_temp; |
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| 118 |
OCR1A = ocr_temp; // Compare A - Turns on transmitter
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OCR1C = ocr_temp; // Reset the timer when match a fires
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| 83 | 120 |
} |
| 84 | 121 |
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// Compare A - Turns on transmitter |
|
| 85 | 123 |
ISR(TIMER1_COMPA_vect) {
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SET_BIT(PORTB, PB4);
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SET_BIT(PORTB, EMIT);
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| 87 | 125 |
sending_counter++; |
| 88 | 126 |
send_next_bit(); |
| 89 | 127 |
} |
| 90 | 128 |
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| 129 |
// Compare B - Turns off transmitter after 320us |
|
| 91 | 130 |
ISR(TIMER1_COMPB_vect) {
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| 92 |
CLEAR_BIT(PORTB, PB4);
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| 131 |
CLEAR_BIT(PORTB, EMIT);
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| 93 | 132 |
if (sending_counter >= 15) {
|
| 94 | 133 |
currently_sending = 0; |
| 95 |
TCCR1 &= ~0x0F; // Stop the timer without clearing CTC1
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| 134 |
stop_timer1();
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| 96 | 135 |
} |
| 97 | 136 |
} |
| 98 | 137 |
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| 99 |
static void send_data(uint16_t data) {
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| 100 |
sending_data = data; |
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sending_counter = 0; |
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currently_sending = 1; |
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TCNT1 = 0; |
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TCCR1 |= _BV(CS12); // Set prescalar to 8 and start timer |
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SET_BIT(PORTB, PB4); |
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send_next_bit(); |
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} |
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| 138 |
//////////////////////////////////////////////////////////////////////////////// |
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| 139 |
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| 108 | 140 |
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| 109 | 141 |
ISR(INT0_vect) {
|
| 110 | 142 |
bom_start(); |
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