--- /dev/null
+/*
+ * Copyright Droids Corporation (2009)
+ * Olivier Matz <zer0@droids-corp.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Revision : $Id: main.c,v 1.8 2009-05-02 10:08:09 zer0 Exp $
+ *
+ */
+
+#include <aversive.h>
+#include <aversive/wait.h>
+
+/*
+ * Leds: PD5 -> PD7
+ * Photodiodes: PC0 PC1
+ * IR: PB1, OC1A
+ */
+
+/*
+ * hfuse: RSTDISBL=1 WTDON=1 SPIEN=0 CKOPT=0 EESAVE=1 BOOTSZ1=0 BOOTSZ0=0 BOOTRST=1
+ * lfuse: BODLEVEL=1 BODEN=1 SUT1=1 SUT0=1 CKSEL3=1 CKSEL2=1 CKSEL1=1 CKSEL0=1
+ */
+
+#define N_PERIODS 10
+#define N_CYCLES_0 17
+#define N_CYCLES_1 17
+#define N_CYCLES_PERIOD (N_CYCLES_0 + N_CYCLES_1)
+
+#define LED_PORT PORTD
+#define LED_DDR DDRD
+#define LED1_BIT 5
+#define LED2_BIT 6
+#define LED3_BIT 7
+
+#define LED_TOGGLE(port, bit) do { \
+ 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)
+#define LED1_TOGGLE() LED_TOGGLE(LED_PORT, LED1_BIT)
+#define LED2_ON() sbi(LED_PORT, LED2_BIT)
+#define LED2_OFF() cbi(LED_PORT, LED2_BIT)
+#define LED2_TOGGLE() LED_TOGGLE(LED_PORT, LED2_BIT)
+#define LED3_ON() sbi(LED_PORT, LED3_BIT)
+#define LED3_OFF() cbi(LED_PORT, LED3_BIT)
+#define LED3_TOGGLE() LED_TOGGLE(LED_PORT, LED3_BIT)
+
+#define IR_PORT PORTB
+#define IR_DDR DDRB
+#define IR_BIT 1
+
+/* FRAME must be odd */
+#define FRAME 0x0B /* in little endian 1-1-0-1 */
+#define FRAME_LEN 4
+
+/* pin returns 1 when nothing, and 0 when laser is on photodiode */
+#define PHOTO_PIN PINC
+#define PHOTO1_BIT 0
+#define PHOTO2_BIT 1
+#define READ_PHOTOS() (PHOTO_PIN & (_BV(PHOTO1_BIT) | _BV(PHOTO2_BIT)))
+#define READ_PHOTO1() (PHOTO_PIN & _BV(PHOTO1_BIT))
+#define READ_PHOTO2() (PHOTO_PIN & _BV(PHOTO2_BIT))
+
+#define PHOTOS_ALL_OFF (_BV(PHOTO1_BIT) | _BV(PHOTO2_BIT))
+#define PHOTOS_ALL_ON (0)
+#define PHOTOS_1ON_2OFF (_BV(PHOTO2_BIT))
+#define PHOTOS_1OFF_2ON (_BV(PHOTO1_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 */
+
+#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 WAIT_LASER
+
+/* basic functions to transmit on IR */
+
+static inline void xmit_0(void)
+{
+ uint8_t t = ((N_CYCLES_PERIOD * N_PERIODS) / 3);
+ TCCR1B = 0;
+ TCCR1A = 0;
+ _delay_loop_1(t); /* 3 cycles per loop */
+}
+
+static inline void xmit_1(void)
+{
+ uint8_t t = ((N_CYCLES_PERIOD * N_PERIODS) / 3);
+ TCCR1B = _BV(WGM13) | _BV(WGM12);
+ TCNT1 = N_CYCLES_PERIOD-1;
+ TCCR1A = _BV(COM1A1) | _BV(WGM11);
+ TCCR1B = _BV(WGM13) | _BV(WGM12) | _BV(CS10);
+ _delay_loop_1(t); /* 3 cycles per loop */
+}
+
+/* transmit in manchester code */
+
+static inline void xmit_manchester_0(void)
+{
+ xmit_0();
+ xmit_1();
+}
+
+static inline void xmit_manchester_1(void)
+{
+ xmit_1();
+ xmit_0();
+}
+
+/* transmit a full frame. Each byte is lsb first. */
+
+static void xmit_bits(uint8_t *buf, uint8_t nbit)
+{
+ uint8_t i;
+ uint8_t byte = *buf;
+
+ for (i=0; i<nbit; i++) {
+ if (byte & 1)
+ xmit_manchester_1();
+ else
+ xmit_manchester_0();
+
+ /* next bit */
+ byte >>= 1;
+
+ /* next byte */
+ if (((i & 0x07) == 0) && (i != 0))
+ byte = *(++buf);
+ }
+ xmit_0();
+}
+
+/* */
+static inline int8_t wait_laser(void)
+{
+ uint8_t photos;
+ uint8_t time;
+ uint8_t diff;
+
+ /* wait until all is off */
+ while (READ_PHOTOS() != PHOTOS_ALL_OFF);
+
+ /* wait an event, it must be photo1 on */
+ while ((photos = READ_PHOTOS()) == PHOTOS_ALL_OFF);
+
+ if (photos != PHOTOS_1ON_2OFF)
+ return -1;
+ time = TCNT0;
+ LED1_ON();
+
+ /* wait an event, it must be photo1 off */
+ while ((photos = READ_PHOTOS()) == PHOTOS_1ON_2OFF) {
+ diff = TCNT0 - time;
+ if (diff > MAX_PHOTO_TIME)
+ return -1;
+ }
+ if (photos != PHOTOS_ALL_OFF)
+ return -1;
+ //time = TCNT0;
+
+ /* wait an event, it must be photo2 on */
+ while ((photos = READ_PHOTOS()) == PHOTOS_ALL_OFF) {
+ diff = TCNT0 - time;
+ if (diff > MAX_INTER_TIME)
+ return -1;
+ }
+ LED2_ON();
+
+ diff = TCNT0 - time;
+ if (diff < MIN_INTER_TIME)
+ return -1;
+ if (photos != PHOTOS_1OFF_2ON)
+ return -1;
+
+#if 0
+ time = TCNT0;
+
+ /* wait an event, it must be photo2 off */
+ while ((photos = READ_PHOTOS()) == PHOTOS_1OFF_2ON) {
+ diff = TCNT0 - time;
+ if (diff > MAX_PHOTO_TIME)
+ return -1;
+ }
+ if (photos != PHOTOS_ALL_OFF)
+ return -1;
+#endif
+
+ /* laser ok */
+ return 0;
+}
+
+/* */
+
+int main(void)
+{
+ /* must be odd */
+ uint8_t frame = FRAME;
+ int8_t ret;
+
+ /* LEDS */
+ LED_DDR = _BV(LED1_BIT) | _BV(LED2_BIT) | _BV(LED3_BIT);
+ IR_DDR |= _BV(IR_BIT);
+
+#if 0
+ while (1) {
+ LED1_ON();
+ wait_ms(500);
+ LED1_OFF();
+ wait_ms(500);
+ }
+#endif
+
+#if 0
+ while (1) {
+ if (READ_PHOTO() & _BV(PHOTO1_BIT))
+ LED1_ON();
+ else
+ LED1_OFF();
+ }
+#endif
+
+ /* configure PWM */
+ ICR1 = N_CYCLES_PERIOD;
+ OCR1A = N_CYCLES_1;
+ TCCR1A = _BV(COM1A1) | _BV(WGM11);
+ TCCR1B = _BV(WGM13) | _BV(WGM12);
+
+ /* configure timer 0, prescaler = 64 */
+ TCCR0 = _BV(CS01) | _BV(CS00);
+
+ while (1) {
+
+#ifdef WAIT_LASER
+ ret = wait_laser();
+
+ LED1_OFF();
+ LED2_OFF();
+
+ if (ret)
+ continue;
+#endif
+
+#if 1
+ LED3_ON();
+ /* ok, transmit frame */
+ xmit_bits(&frame, FRAME_LEN);
+
+ /* 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;
+}
git.droids-corp.org / aversive.git / blobdiff