Revision ec9e417d
| ID | ec9e417da9689f8ed4cf566110abcaf8f462f876 |
Added second range sensor to scout_avr
Not yet tested.
| scout_avr/src/range.cpp | ||
|---|---|---|
| 17 | 17 |
// so that we can test on a 328 |
| 18 | 18 |
#if defined(__AVR_ATmega128RFA1__) |
| 19 | 19 |
# define read_INT0 (PIND & _BV(PD0)) |
| 20 |
# define read_INT1 (PIND & _BV(PD1)) |
|
| 20 | 21 |
#elif defined(__AVR_ATmega328P__) || defined(__AVR_ATmega328__) |
| 21 | 22 |
# define read_INT0 (PIND & _BV(PD2)) |
| 23 |
# define read_INT1 (PIND & _BV(PD3)) |
|
| 22 | 24 |
#else |
| 23 |
# error "Please define read_INT0 for this device"
|
|
| 25 |
# error "Please define read_INTx for this device"
|
|
| 24 | 26 |
#endif |
| 25 | 27 |
|
| 28 |
struct range_t {
|
|
| 29 |
unsigned int start; // timer value on rising edge |
|
| 30 |
unsigned int value; // last measured range |
|
| 31 |
} range[2]; |
|
| 32 |
|
|
| 26 | 33 |
unsigned int range; |
| 27 | 34 |
|
| 28 |
ISR(INT0_vect)
|
|
| 35 |
static void on_edge(int which)
|
|
| 29 | 36 |
{
|
| 37 |
unsigned int time = TCNT1; |
|
| 30 | 38 |
if (read_INT0) |
| 31 | 39 |
{
|
| 32 |
// reset timer |
|
| 33 |
TCNT1 = 0; |
|
| 40 |
range[which].start = time; |
|
| 34 | 41 |
} |
| 35 | 42 |
else |
| 36 | 43 |
{
|
| 37 |
range = TCNT1; |
|
| 44 |
// if timer overflowed since start, this arithmetic should still work out |
|
| 45 |
range[which].value = time - range[which].start; |
|
| 38 | 46 |
} |
| 39 | 47 |
} |
| 40 | 48 |
|
| 49 |
ISR(INT0_vect) |
|
| 50 |
{
|
|
| 51 |
on_edge(0); |
|
| 52 |
} |
|
| 53 |
|
|
| 54 |
ISR(INT1_vect) |
|
| 55 |
{
|
|
| 56 |
on_edge(1); |
|
| 57 |
} |
|
| 58 |
|
|
| 41 | 59 |
void range_init() |
| 42 | 60 |
{
|
| 43 |
// ISC0 = 1, edge triggered
|
|
| 44 |
EICRA |= _BV(ISC00); |
|
| 45 |
// enable INT0 |
|
| 46 |
EIMSK |= _BV(INT0); |
|
| 61 |
// ISCx = 1, edge triggered
|
|
| 62 |
EICRA |= _BV(ISC10) | _BV(ISC00);
|
|
| 63 |
// enable INT0 and INT1
|
|
| 64 |
EIMSK |= _BV(INT1) | _BV(INT0);
|
|
| 47 | 65 |
|
| 48 | 66 |
// CS1 = 2, 1/8 prescaler |
| 49 | 67 |
TCCR1B = _BV(CS11); |
| ... | ... | |
| 51 | 69 |
range = -1; |
| 52 | 70 |
} |
| 53 | 71 |
|
| 54 |
int range_get()
|
|
| 72 |
unsigned int range_get(int which)
|
|
| 55 | 73 |
{
|
| 56 |
int ret; |
|
| 57 |
cli(); |
|
| 58 |
ret = range; |
|
| 59 |
sei(); |
|
| 60 |
return ret; |
|
| 74 |
unsigned int ret; |
|
| 75 |
if (0 <= which && which <= 1) |
|
| 76 |
{
|
|
| 77 |
cli(); |
|
| 78 |
ret = range[which].value; |
|
| 79 |
sei(); |
|
| 80 |
return ret; |
|
| 81 |
} |
|
| 82 |
else return 0xFFFF; |
|
| 61 | 83 |
} |
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