poll input capture register

[protos/rc_servos.git] / main.c

diff --git a/main.c b/main.c
index 2e2f13a..82739b0 100644 (file)
--- a/main.c
+++ b/main.c
@@ -1,4 +1,5 @@
 #include <aversive.h>
+#include <aversive/wait.h>
 
 struct servo {
        uint8_t bit;
@@ -7,28 +8,47 @@ struct servo {
 
 static struct servo servo_table[] = {
        {
-               .bit = 0,
-               .command = 0,
+               .bit = 2,
+               .command = 300,
+       },
+       {
+               .bit = 3,
+               .command = 700,
        },
        {
-               .bit = 1,
+               .bit = 4,
                .command = 512,
        },
        {
-               .bit = 2,
-               .command = 1023,
+               .bit = 5,
+               .command = 512,
+       },
+       {
+               .bit = 6,
+               .command = 512,
+       },
+       {
+               .bit = 7,
+               .command = 512,
        },
 };
 #define NB_SERVO (sizeof(servo_table)/sizeof(*servo_table))
 
-static volatile uint8_t bypass;
+static uint8_t bypass;
 static volatile uint8_t done;
-static volatile uint8_t portval;
-static volatile uint8_t rxidx;
+static uint8_t portval;
+static uint8_t rxidx;
+
+static uint8_t icp_idx = NB_SERVO;
+static uint16_t icp_servos[NB_SERVO];
+static uint16_t icp_prev;
 
 #define BYPASS_ENABLE 14
 #define BYPASS_DISABLE 15
 
+#define LED_ON() do { PORTB |= 0x02; } while(0)
+#define LED_OFF() do { PORTB &= ~0x02; } while(0)
+
 /*
  * SPI protocol:
  *
@@ -40,7 +60,7 @@ static volatile uint8_t rxidx;
  * Command 14 is to enable bypass mode.
  * Command 15 is to disable bypass mode.
  */
-static volatile union {
+static union {
        uint8_t u8;
        struct {
                /* inverted: little endian */
@@ -50,7 +70,7 @@ static volatile union {
        };
 } byte0;
 
-static volatile union {
+static union {
        uint8_t u8;
        struct {
                /* inverted: little endian */
@@ -61,7 +81,7 @@ static volatile union {
 
 SIGNAL(TIMER1_COMPA_vect)
 {
-       PORTC = portval;
+       PORTD = portval;
        TIMSK1 &= ~_BV(OCIE1A);
        done = 1;
 }
@@ -110,6 +130,53 @@ static void poll_spi(void)
        rxidx ^= 1;
 }
 
+static void poll_input_capture(void)
+{
+       uint16_t icp, diff;
+       uint8_t rising;
+
+       /* no new sample, return */
+       if ((TIFR1 & _BV(ICF1)) == 0)
+               return;
+
+       sei();
+       icp = ICR1;
+       cli();
+
+       rising = TCCR1B & _BV(ICES1);
+
+       /* change the edge type */
+       TCCR1B ^= _BV(ICES1);
+
+       /* clear the flag */
+       TIFR1 = TIFR1 | _BV(ICF1);
+
+       diff = icp - icp_prev;
+       icp_prev = icp;
+
+       /* a rising edge with at least 2ms of state 0 means that we
+        * get the first servo */
+       if (rising == 1 && diff > 2000) {
+               icp_idx = 0;
+               return;
+       }
+
+       /* get the value for the servo */
+       if (rising == 0 && icp_idx < NB_SERVO) {
+               if (diff < 1000)
+                       icp_servos[icp_idx] = 0;
+               else
+                       icp_servos[icp_idx] = diff - 1000;
+               icp_idx++;
+       }
+}
+
+static void poll(void)
+{
+       poll_spi();
+       poll_input_capture();
+}
+
 static void load_timer_at(uint16_t t)
 {
        OCR1A = t;
@@ -125,33 +192,47 @@ static void do_one_servo(struct servo *s)
        //portval = PORTC | (1 << s->bit);
        portval = (1 << s->bit);
        t = TCNT1;
-       load_timer_at(t + 150);
+       load_timer_at(t + 20);
        while (done == 0)
-               poll_spi();
+               poll();
 
        /* reset bit */
        done = 0;
        portval = 0;
        //portval = PORTC & (~(1 << s->bit));
-       load_timer_at(t + 150 + 8000 + s->command * 8);
+       load_timer_at(t + 20 + 1000 + s->command);
        while (done == 0)
-               poll_spi();
+               poll();
 }
 
 int main(void)
 {
        uint8_t i;
        uint8_t t, diff;
+       uint8_t tmp;
+
+       /* use pull-up for inputs */
+       PORTC |= 0x3f;
 
        /* LED */
-       DDRB = 0x20;
+       DDRB = 0x02;
 
-       /* servo outputs */
-       DDRC = 0x7;
+#if 0 /* LED debug */
+       while (1) {
+               LED_ON();
+               wait_ms(100);
+               LED_OFF();
+               wait_ms(100);
+       }
+#endif
 
-       /* start timer1 at clk/1 (8Mhz) */
+       /* servo outputs PD2-PD7 */
+       DDRD = 0xfc;
+
+       /* start timer1 at clk/8 (1Mhz), enable noise canceler on
+        * input capture, capture rising edge */
        TCNT1 = 0;
-       TCCR1B = _BV(CS10);
+       TCCR1B = _BV(CS11) | _BV(ICNC1) | _BV(ICES1);
 
        /* start timer0 at clk/1024 (~8Khz) */
        TCNT0 = 0;
@@ -173,11 +254,20 @@ int main(void)
                        diff = TCNT0 - t;
                        if (diff >= 160)
                                break;
-                       poll_spi();
+                       poll();
                }
                /* bypass mode */
-               while (bypass == 1) {
-                       PORTC = PORTB;
+               if (bypass == 1) {
+                       LED_ON();
+
+                       while (bypass == 1) {
+                               tmp = PINC;
+                               tmp &= 0x3f;
+                               tmp <<= 2;
+                               PORTD = tmp;
+                               poll();
+                       }
+                       LED_OFF();
                }
        }