Revision b2554c5c
Begin cleaning up bom code
scout_avr/bom/bom.c | ||
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18 | 18 |
#define TIME_US(us) (F_CPU * (us) / 1000000 / PRESCALAR) |
19 | 19 |
|
20 | 20 |
#define ADDRESS 0x3 |
21 |
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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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27 |
// TODO start timer0 |
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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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#define DETECT PB2 |
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#define EMIT PB4 |
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34 | 23 |
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35 | 24 |
static void bom_init(void) { |
36 | 25 |
|
... | ... | |
38 | 27 |
//EICRA |= _BV(ISC01) | _BV(ISC00); |
39 | 28 |
//EIMSK |= _BV(INT0); |
40 | 29 |
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// setup timer 0 |
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TCCR0B |= _BV(CS01); |
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TIMSK |= _BV(OCIE0A); |
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init_timer0(); |
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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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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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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(); |
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} |
56 | 41 |
|
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////////////////////////////////// Receiving /////////////////////////////////// |
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|
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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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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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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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ISR(TIMER0_COMPA_vect) { |
58 | 66 |
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char this_bit = READ_BIT(PINB, PB2);
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char this_bit = READ_BIT(PINB, DETECT);
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60 | 68 |
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61 | 69 |
if (this_bit == 0) { |
62 | 70 |
if (last_bit == 0) { |
63 |
bom_stop();
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stop_detect();
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|
64 | 72 |
} |
65 | 73 |
} else { |
66 | 74 |
data = data << 1 | (~last_bit & 1); |
... | ... | |
70 | 78 |
last_bit = this_bit; |
71 | 79 |
|
72 | 80 |
if (count == 15) { |
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stop_detect(); |
|
73 | 82 |
smb_send_data(&data, sizeof(data)); |
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bom_stop(); |
|
75 | 83 |
} |
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} |
77 | 85 |
|
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//////////////////////////////////////////////////////////////////////////////// |
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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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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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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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currently_sending = 1; |
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SET_BIT(PORTB, EMIT); |
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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; |
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OCR1C = ocr_temp; |
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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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sending_counter++; |
88 | 126 |
send_next_bit(); |
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} |
90 | 128 |
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// Compare B - Turns off transmitter after 320us |
|
91 | 130 |
ISR(TIMER1_COMPB_vect) { |
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CLEAR_BIT(PORTB, PB4);
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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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stop_timer1();
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96 | 135 |
} |
97 | 136 |
} |
98 | 137 |
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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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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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//////////////////////////////////////////////////////////////////////////////// |
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108 | 140 |
|
109 | 141 |
ISR(INT0_vect) { |
110 | 142 |
bom_start(); |
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