X-Git-Url: http://git.droids-corp.org/?p=aversive.git;a=blobdiff_plain;f=projects%2Fmicrob2010%2Ftests%2Fstatic_beacon%2Fstatic_beacon.c;h=9f9c8d61ed43a897acb7ffd99899aa0b09d9d161;hp=c34838c0757e1c304433736ced4d847393277290;hb=aa0ebd8b43a0e48d791864ae3268e78d980a70e9;hpb=7e6058416582109d4b73ec4e0c923eb471c36844 diff --git a/projects/microb2010/tests/static_beacon/static_beacon.c b/projects/microb2010/tests/static_beacon/static_beacon.c index c34838c..9f9c8d6 100755 --- a/projects/microb2010/tests/static_beacon/static_beacon.c +++ b/projects/microb2010/tests/static_beacon/static_beacon.c @@ -20,6 +20,8 @@ * */ +#include + #include #include @@ -36,9 +38,43 @@ * lfuse: BODLEVEL=1 BODEN=1 SUT1=1 SUT0=1 CKSEL3=1 CKSEL2=1 CKSEL1=1 CKSEL0=1 */ +//#define NO_MODULATION +#define WAIT_LASER +//#define MODUL_455KHZ +//#define MODUL_56KHZ +#define MODUL_38KHZ +//#define SPEED_40RPS +#define SPEED_10RPS + +/* beacon identifier: must be odd, 3 bits */ +#define BEACON_ID 0x1 +#define BEACON_ID_MASK 0x7 +#define BEACON_ID_SHIFT 0 + +/* */ +#define FRAME_DATA_MASK 0x0FF8 +#define FRAME_DATA_SHIFT 3 + +#if (defined MODUL_455KHZ) #define N_PERIODS 10 #define N_CYCLES_0 17 #define N_CYCLES_1 17 +#elif (defined MODUL_56KHZ) +#define N_PERIODS 15 +#define N_CYCLES_0 143 +#define N_CYCLES_1 143 +#elif (defined MODUL_38KHZ) +#define N_PERIODS 15 +#define N_CYCLES_0 210 +#define N_CYCLES_1 210 +#else +#error "no freq defined" +#endif + +#define MIN_DIST 150. +#define MAX_DIST 3600. +#define LASER_DIST 25. + #define N_CYCLES_PERIOD (N_CYCLES_0 + N_CYCLES_1) #define LED_PORT PORTD @@ -48,11 +84,11 @@ #define LED3_BIT 7 #define LED_TOGGLE(port, bit) do { \ - if (port & _BV(bit)) \ - port &= ~_BV(bit); \ - else \ - port |= _BV(bit); \ - } while(0) + if (port & _BV(bit)) \ + port &= ~_BV(bit); \ + else \ + port |= _BV(bit); \ + } while(0) #define LED1_ON() sbi(LED_PORT, LED1_BIT) #define LED1_OFF() cbi(LED_PORT, LED1_BIT) @@ -75,49 +111,52 @@ #define FRAME_LEN 16 /* pin returns !0 when nothing, and 0 when laser is on photodiode */ -#define PHOTO_PIN PINC +#define PHOTO_PIN PINB #define PHOTO_BIT 0 #define READ_PHOTO() (!!(PHOTO_PIN & (_BV(PHOTO_BIT)))) -/* in cycles/64 (unit is 4 us at 16Mhz) */ -#define MAX_PHOTO_TIME ((uint8_t)25) /* t=100us len=5mm rps=40Hz dist=20cm */ - -/* XXX to be recalculated */ -#define MIN_INTER_TIME ((uint8_t)12) /* t=50us len=50mm rps=40Hz dist=350cm */ -#define MAX_INTER_TIME ((uint8_t)250) /* t=1000us len=50mm rps=40Hz dist=20cm */ - -/* in ms */ -#define INTER_LASER_TIME 10 - -//#define NO_MODULATION -#define WAIT_LASER +/* IR_DELAY **must** be < 32768 */ +#if (defined SPEED_10RPS) +#define MIN_INTER_TIME ((uint16_t)(160*2)) /* t~=160us dist=350cm */ +#define MAX_INTER_TIME ((uint16_t)(8000*2)) /* t=8ms dist=10cm */ +#define IR_DELAY ((uint16_t)(8000*2)) +#define INTER_LASER_TIME 30 /* in ms */ +#elif (defined SPEED_40RPS) +#define MIN_INTER_TIME ((uint16_t)(40*16)) /* t~=40us dist=350cm */ +#define MAX_INTER_TIME ((uint16_t)(2000*16)) /* t=2ms dist=10cm */ +#define IR_DELAY ((uint16_t)(2000*16)) +#define INTER_LASER_TIME 10 /* in ms */ +#else +#error "speed not defined" +#endif /* basic functions to transmit on IR */ static inline void xmit_0(void) { - uint8_t t = ((N_CYCLES_PERIOD * N_PERIODS) / 3); + uint16_t t = ((N_CYCLES_PERIOD * N_PERIODS) / 4); #ifdef NO_MODULATION cbi(IR_PORT, IR_BIT); #else TCCR1B = 0; TCCR1A = 0; #endif - _delay_loop_1(t); /* 3 cycles per loop */ + _delay_loop_2(t); /* 4 cycles per loop */ } static inline void xmit_1(void) { - uint8_t t = ((N_CYCLES_PERIOD * N_PERIODS) / 3); + uint16_t t = ((N_CYCLES_PERIOD * N_PERIODS) / 4); #ifdef NO_MODULATION sbi(IR_PORT, IR_BIT); #else TCCR1B = _BV(WGM13) | _BV(WGM12); TCNT1 = N_CYCLES_PERIOD-1; TCCR1A = _BV(COM1A1) | _BV(WGM11); + ICR1 = N_CYCLES_PERIOD; TCCR1B = _BV(WGM13) | _BV(WGM12) | _BV(CS10); #endif - _delay_loop_1(t); /* 3 cycles per loop */ + _delay_loop_2(t); /* 4 cycles per loop */ } /* transmit in manchester code */ @@ -152,62 +191,123 @@ static void xmit_bits(uint32_t frame, uint8_t nbit) xmit_0(); } -/* */ -static inline int8_t wait_laser(void) +#ifdef WAIT_LASER +/* val is 12 bits. Return the 16 bits value that includes the 4 bits + * cksum in MSB. */ +static uint16_t do_cksum(uint16_t val) { - uint8_t photos; - uint8_t time1, time2; - uint8_t diff; - - /* - wait photo on - wait photo off - wait photo on or timeout - wait photo off - should return the amount of time to wait - */ - - /* wait until all is off */ - while (READ_PHOTO() != 0); - - /* wait until photo is on */ - while (READ_PHOTO() != 1); - time1 = TCNT0; + uint16_t x, cksum; + + x = (val & 0xfff); + /* add the three 4-bits blocks of x together */ + cksum = x & 0xf; + x = x >> 4; + cksum += x & 0xf; + cksum = (cksum & 0xf) + ((cksum & 0xf0) >> 4); + x = x >> 4; + cksum += x & 0xf; + cksum = (cksum & 0xf) + ((cksum & 0xf0) >> 4); + cksum = (~cksum) & 0xf; + return (cksum << 12) + (val & 0xfff); +} + +/* get the frame from laser time difference, return 0 on error (this + * frame cannot be sent). */ +static uint32_t get_frame(uint16_t laserdiff) +{ + uint32_t frame = 0; + double a, d; + uint16_t frame_dist; + + frame |= ((uint32_t)BEACON_ID << BEACON_ID_SHIFT); + + /* process angle from laserdiff time */ +#ifdef SPEED_10RPS + /* timer = 2Mhz */ + a = ((double)laserdiff / (2000000./10.)) * 2. * M_PI; +#else + /* timer = 16Mhz */ + a = ((double)laserdiff / (16000000./40.)) * 2. * M_PI; +#endif + /* get distance from angle */ + d = LASER_DIST / sin(a/2); + + /* scale it between 0 and 511 */ + if (d <= MIN_DIST) + return 0; + if (d >= MAX_DIST) + return 0; + d -= MIN_DIST; + d /= (MAX_DIST-MIN_DIST); + d *= 512; + frame_dist = (uint16_t)d; + if (frame_dist >= 512) /* should not happen... */ + return 0; + + frame |= ((uint32_t)(frame_dist & FRAME_DATA_MASK) << FRAME_DATA_SHIFT); + + /* process cksum and return */ + return do_cksum(frame); +} + +/* Wait 2 consecutive rising edges on photodiode. Return 0 on success, + * in this case, the 'when' pointed area is assigned to the time when + * IR signal should be sent. The 'laserdiff' pointer is the time + * between the 2 lasers, in timer unit. */ +static inline int8_t wait_laser(uint16_t *when, uint16_t *laserdiff) +{ + uint16_t time1, time2; + uint16_t diff; + +#ifdef SPEED_40RPS + /* set timer to 16Mhz, we will use ICP */ + TCCR1A = 0; + TCCR1B = _BV(CS10); +#else /* 10 RPS */ + /* set timer to 2Mhz, we will use ICP */ + TCCR1A = 0; + TCCR1B = _BV(CS11); +#endif + + /* wait until all is off (inverted logic) */ + while (READ_PHOTO() == 0); + TIFR = _BV(ICF1); + + /* wait falling edge */ + while ((TIFR & _BV(ICF1)) == 0); + time1 = ICR1; + LED1_ON(); - /* wait until photo is off, if it takes too long time, - * return. */ - while (READ_PHOTO() != 0) { - diff = TCNT0 - time1; - if (diff > MAX_PHOTO_TIME) - return -1; - } + /* wait a bit to avoid oscillations */ + while ((uint16_t)(TCNT1-time1) < MIN_INTER_TIME); + TIFR = _BV(ICF1); - /* wait photo on. */ - while (READ_PHOTO() != 1) { - diff = TCNT0 - time1; + /* wait next falling edge + timeout */ + while ((TIFR & _BV(ICF1)) == 0) { + diff = TCNT1 - time1; if (diff > MAX_INTER_TIME) return -1; } - time2 = TCNT0; - - /* wait until photo is off, if it takes too long time, - * return. */ - while (READ_PHOTO() != 0) { - diff = TCNT0 - time2; - if (diff > MAX_PHOTO_TIME) - return -1; - } LED2_ON(); + /* get time of 2nd laser */ + time2 = ICR1; + TIFR = _BV(ICF1); + + /* process time difference */ diff = time2 - time1; if (diff < MIN_INTER_TIME) return -1; + *when = time1 + (diff/2) + IR_DELAY; + *laserdiff = diff; + /* laser ok */ return 0; } +#endif /* */ @@ -215,9 +315,11 @@ int main(void) { /* must be odd */ uint32_t frame = FRAME; +#ifdef WAIT_LASER int8_t ret; - int16_t c; - + uint16_t when = 0; + uint16_t diff = 0; +#endif /* LEDS */ LED_DDR = _BV(LED1_BIT) | _BV(LED2_BIT) | _BV(LED3_BIT); IR_DDR |= _BV(IR_BIT); @@ -228,6 +330,7 @@ int main(void) #if 0 while (1) { + int16_t c; c = uart_recv_nowait(0); if (c != -1) printf("%c", (char)(c+1)); @@ -240,7 +343,7 @@ int main(void) #if 0 while (1) { - if (READ_PHOTO() & _BV(PHOTO1_BIT)) + if (READ_PHOTO()) LED1_ON(); else LED1_OFF(); @@ -255,34 +358,51 @@ int main(void) TCCR1B = _BV(WGM13) | _BV(WGM12); #endif +#if 0 + /* test freq */ + ICR1 = N_CYCLES_PERIOD; + OCR1A = N_CYCLES_1; + TCCR1B = _BV(WGM13) | _BV(WGM12); + TCNT1 = N_CYCLES_PERIOD-1; + TCCR1A = _BV(COM1A1) | _BV(WGM11); + TCCR1B = _BV(WGM13) | _BV(WGM12) | _BV(CS10); + while (1); +#endif + + /* configure timer 0, prescaler = 64 */ TCCR0 = _BV(CS01) | _BV(CS00); while (1) { #ifdef WAIT_LASER - ret = wait_laser(); + ret = wait_laser(&when, &diff); LED1_OFF(); LED2_OFF(); if (ret) continue; + + frame = get_frame(diff); + /* cannot convert into frame... skip it */ + if (frame == 0) { + wait_ms(INTER_LASER_TIME); + continue; + } + + /* wait before IR xmit */ + while ((int16_t)(when-TCNT1) > 0); #endif -#if 1 LED3_ON(); /* ok, transmit frame */ xmit_bits(frame, FRAME_LEN); + LED3_OFF(); + /* don't watch a laser during this time */ wait_ms(INTER_LASER_TIME); - LED3_OFF(); -#else - LED1_ON(); - wait_ms(1); - LED1_OFF(); -#endif } return 0; }