--- /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>
+
+#include <uart.h>
+#include <pid.h>
+#include <pwm_ng.h>
+#include <parse.h>
+#include <rdline.h>
+
+#include "cmdline.h"
+#include "main.h"
+
+/******************* TSOP */
+
+#define EICRx_TSOP EICRB /* EICRA is not ok, cannot do intr on any edge */
+#ifdef BOARD2006
+#define INTx_TSOP INT6
+#define ISCx0_TSOP ISC60
+#define ISCx1_TSOP ISC61
+#define SIG_TSOP SIG_INTERRUPT6
+#define TSOP_READ() (PINE & 0x40)
+#else
+#define INTx_TSOP INT4
+#define ISCx0_TSOP ISC40
+#define ISCx1_TSOP ISC41
+#define SIG_TSOP SIG_INTERRUPT4
+#define TSOP_READ() (PINE & 0x10)
+#endif
+
+#define TSOP_FREQ_MHZ 0.455
+#define TSOP_PERIOD_US (1./TSOP_FREQ_MHZ)
+#define N_PERIODS 10.
+
+#define TSOP_TIME_SHORT_US (1.5 * N_PERIODS * TSOP_PERIOD_US)
+#define TSOP_TIME_LONG_US (2.5 * N_PERIODS * TSOP_PERIOD_US)
+
+#define TSOP_TIME_SHORT ((uint16_t)(TSOP_TIME_SHORT_US*2))
+#define TSOP_TIME_LONG ((uint16_t)(TSOP_TIME_LONG_US*2))
+
+#define FRAME_LEN 16
+
+/* frame */
+static uint16_t start_angle_time;
+static uint16_t frame;
+static uint16_t mask;
+static uint8_t len;
+static uint8_t val;
+
+struct detected_frame {
+ uint16_t frame;
+ uint16_t time;
+};
+
+#define FRAME_RING_ORDER 4
+#define FRAME_RING_SIZE (1<<FRAME_RING_ORDER)
+#define FRAME_RING_MASK (FRAME_RING_SIZE-1)
+static uint8_t frame_ring_head = 0;
+static uint8_t frame_ring_tail = 0;
+static struct detected_frame frame_ring[FRAME_RING_SIZE];
+
+/********************** CS */
+
+/* 8ms, easier if it's a pow of 2 */
+#define CS_PERIOD_US (8192)
+#define CS_PERIOD ((uint16_t)(CS_PERIOD_US*2))
+#define CPT_ICR_MAX (uint8_t)((1000000UL/(uint32_t)CS_PERIOD_US)) /* too slow = 1 tr/s */
+#define CPT_ICR_MIN (uint8_t)((10000UL/(uint32_t)CS_PERIOD_US)) /* too fast = 100 tr/s */
+
+/* in tr / 1000s */
+#define CS_CONSIGN (25 * 1000L)
+
+/* pwm for laser:
+ * - clear on timer compare (CTC)
+ * - Toggle OC0 on compare match
+ * - prescaler = 1 */
+#define LASER_ON() do { TCCR0 = _BV(WGM01) | _BV(COM00) | _BV(CS00); } while (0)
+#define LASER_OFF() do { TCCR0 = 0; } while (0)
+
+struct beacon_tsop beacon_tsop;
+
+void debug_serial(void)
+{
+#if 0
+ while (1) {
+ int16_t c;
+ c = uart_recv_nowait(0);
+ if (c != -1)
+ printf("%c", (char)(c+1));
+ LED1_ON();
+ wait_ms(500);
+ LED1_OFF();
+ wait_ms(500);
+ }
+#endif
+}
+
+void debug_tsop(void)
+{
+#if 0
+ while (1) {
+ if (TSOP_READ())
+ LED1_OFF();
+ else {
+ LED1_ON();
+ wait_ms(500);
+ }
+ }
+#endif
+}
+
+/* decode frame */
+SIGNAL(SIG_TSOP) {
+ static uint8_t led_cpt = 0;
+
+ /* tsop status */
+ static uint8_t prev_tsop = 0;
+ uint8_t cur_tsop;
+
+ /* time */
+ static uint16_t prev_time;
+ uint16_t ref_time;
+ uint16_t cur_time;
+ uint16_t diff_time;
+
+ ref_time = ICR3;
+ cur_time = TCNT3;
+ cur_tsop = TSOP_READ();
+ diff_time = cur_time - prev_time;
+
+ /* first rising edge */
+ if (cur_tsop && diff_time > TSOP_TIME_LONG) {
+ len = 1;
+ val = 1;
+ frame = 0;
+ start_angle_time = cur_time - ref_time;
+ mask = 1;
+ }
+ /* any short edge */
+ else if (diff_time < TSOP_TIME_SHORT) {
+ if (len & 1) {
+ if (val)
+ frame |= mask;
+ mask <<= 1;
+ }
+ len ++;
+ }
+ /* any long edge */
+ else if (diff_time < TSOP_TIME_LONG) {
+ val = !val;
+ if (val)
+ frame |= mask;
+ mask <<= 1;
+ len += 2;
+ }
+
+ /* end of frame */
+ if (len == FRAME_LEN*2) {
+ uint8_t tail_next = (frame_ring_tail+1) & FRAME_RING_MASK;
+ if (tail_next != frame_ring_head) {
+ frame_ring[frame_ring_tail].frame = frame;
+ frame_ring[frame_ring_tail].time = start_angle_time;
+ frame_ring_tail = tail_next;
+ }
+ if (led_cpt & 0x8)
+ LED3_TOGGLE();
+ led_cpt ++;
+ }
+
+ prev_time = cur_time;
+ prev_tsop = cur_tsop;
+}
+
+/* absolute value */
+static inline int32_t AbS(int32_t x)
+{
+ if (x > 0)
+ return x;
+ else
+ return -x;
+}
+
+/* Get the speed of motor (tr / 1000s)
+ * - icr_cpt is the number of CS period between 2 ICR updates
+ * - icr_diff is the difference of ICR values between the ICR updates
+ * (modulo 65536 obviously) */
+static inline int32_t get_speed(uint8_t icr_cpt, uint16_t icr_diff)
+{
+ int32_t best_diff = 65536L;
+ int8_t best_cpt = -2;
+ int32_t diff;
+ int8_t i;
+
+ /* too slow (less than 1 tr/s) */
+ if (icr_cpt > CPT_ICR_MAX)
+ return 1000L;
+
+ /* too fast (more than 100 tr/s) */
+ if (icr_cpt < CPT_ICR_MIN)
+ return 100000L;
+
+ /* try to get the real time knowning icr_cpt and icr_diff */
+ for (i=-1; i<2; i++) {
+ diff = ((icr_cpt+i)&3) * 16384L;
+ diff += (icr_diff & 0x3fff);
+ diff -= icr_diff;
+ if (diff > 32768L)
+ diff -= 65536L;
+ if (diff < -32768)
+ diff += 65536L;
+
+ if (AbS(diff) < AbS(best_diff)) {
+ best_diff = diff;
+ best_cpt = icr_cpt + i;
+ }
+ }
+
+ /* real time difference in 1/2 us */
+ diff = (best_cpt * 16384L) + (icr_diff & 0x3fff);
+ return 2000000000L/diff;
+}
+
+int main(void)
+{
+ uint16_t prev_cs = 0;
+ uint16_t prev_icr = 0;
+ uint16_t icr = 0;
+ uint16_t diff_icr = 0;
+ uint8_t cpt_icr = 0;
+ uint8_t cpt = 0;
+ int32_t speed, out, err;
+ uint16_t tcnt3;
+ uint8_t x = 0;
+
+ /* LEDS */
+ LED1_DDR |= _BV(LED1_BIT);
+ LED2_DDR |= _BV(LED2_BIT);
+ LED3_DDR |= _BV(LED3_BIT);
+ DDRB |= 0x10; /* OC0 (laser pwm) */
+
+ /* PID init */
+ pid_init(&beacon_tsop.pid);
+ pid_set_gains(&beacon_tsop.pid, 500, 0, 0);
+ pid_set_maximums(&beacon_tsop.pid, 0, 20000, 4095);
+ pid_set_out_shift(&beacon_tsop.pid, 10);
+ pid_set_derivate_filter(&beacon_tsop.pid, 4);
+
+ uart_init();
+ fdevopen(uart0_dev_send, uart0_dev_recv);
+
+ rdline_init(&beacon_tsop.rdl, write_char, valid_buffer, complete_buffer);
+ snprintf(beacon_tsop.prompt, sizeof(beacon_tsop.prompt), "beacon > ");
+ rdline_newline(&beacon_tsop.rdl, beacon_tsop.prompt);
+
+ debug_tsop();
+ debug_serial();
+
+ /* configure external interrupt for TSOP */
+ EICRx_TSOP |= _BV(ISCx0_TSOP);
+ EIMSK |= _BV(INTx_TSOP);
+
+ /* pwm for motor */
+ PWM_NG_TIMER_16BITS_INIT(1, TIMER_16_MODE_PWM_10,
+ TIMER1_PRESCALER_DIV_1);
+ PWM_NG_INIT16(&beacon_tsop.pwm_motor, 1, A, 10, 0, NULL, 0);
+
+ /* pwm for laser:
+ * - clear on timer compare (CTC)
+ * - Toggle OC0 on compare match
+ * - prescaler = 1 */
+ TCCR0 = _BV(WGM01) | _BV(COM00) | _BV(CS00);
+ OCR0 = 80; /* f = 100 khz at 16 Mhz */
+
+ /* configure timer 3: CLK/8
+ * it is used as a reference time
+ * enable noise canceller for ICP3 */
+ TCCR3B = _BV(ICNC3) | _BV(CS11);
+
+ sei();
+
+ /* Control system will be done in main loop */
+ while (1) {
+
+ /* process pending bytes on uart */
+ cmdline_process();
+
+ /* monitor the value of ICR (which is modified
+ * automatically on TT rising edge). If the value
+ * changed, process the time difference. */
+ if (ETIFR & _BV(ICF3)) {
+ cli();
+ icr = ICR3;
+ sei();
+ ETIFR = _BV(ICF3);
+
+ LED2_TOGGLE();
+ diff_icr = (icr - prev_icr);
+ cpt_icr = cpt;
+ prev_icr = icr;
+ cpt = 0;
+ speed = get_speed(cpt_icr, diff_icr);
+ }
+
+ /* read time reference */
+ cli();
+ tcnt3 = TCNT3;
+ sei();
+
+ /* wait cs period */
+ if (tcnt3 - prev_cs < CS_PERIOD)
+ continue;
+
+ /* CS LED */
+ if (x & 0x80)
+ LED1_ON();
+ else
+ LED1_OFF();
+ x++;
+
+ /* process CS... maybe we don't need to use
+ * control_system_manager, just PID is enough */
+ if (cpt == CPT_ICR_MAX)
+ speed = 0;
+ else
+ speed = get_speed(cpt_icr, diff_icr);
+
+ /* enabled laser when rotation speed if at least 5tr/s */
+ if (speed > 5000)
+ LASER_ON();
+ else
+ LASER_OFF();
+
+ err = CS_CONSIGN - speed;
+ out = pid_do_filter(&beacon_tsop.pid, err);
+ if (x == 0 && beacon_tsop.debug_speed)
+ printf("%ld %ld\n", speed, out);
+ if (out < 0)
+ out = 0;
+ /* XXX */
+ if (out > 2000)
+ out = 2000;
+
+ pwm_ng_set(&beacon_tsop.pwm_motor, out);
+
+ prev_cs = tcnt3;
+
+ /* count the number of CS period between 2 ICR
+ * captures */
+ if (cpt < CPT_ICR_MAX)
+ cpt ++;
+
+ /* after CS, check if we have a new frame in ring */
+ if (frame_ring_head != frame_ring_tail) {
+ uint8_t head_next;
+ head_next = (frame_ring_head+1) & FRAME_RING_MASK;
+ if (beacon_tsop.debug_frame)
+ printf("%x %d\n", frame_ring[frame_ring_head].frame,
+ frame_ring[frame_ring_head].time);
+ frame_ring_head = head_next;
+ }
+
+ }
+
+ return 0;
+}