change prescaler of timer1 from 1 to 8

[protos/rc_servos.git] / main.c

diff --git a/main.c b/main.c
index dd98345..5849b8b 100644 (file)
--- a/main.c
+++ b/main.c
@@ -1,4 +1,5 @@
 #include <aversive.h>
+#include <aversive/wait.h>
 
 struct servo {
        uint8_t bit;
@@ -6,9 +7,13 @@ struct servo {
 };
 
 static struct servo servo_table[] = {
+       {
+               .bit = 2,
+               .command = 300,
+       },
        {
                .bit = 3,
-               .command = 0,
+               .command = 700,
        },
        {
                .bit = 4,
@@ -29,14 +34,17 @@ static struct servo servo_table[] = {
 };
 #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;
 
 #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:
  *
@@ -48,7 +56,7 @@ 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 */
@@ -58,7 +66,7 @@ static volatile union {
        };
 } byte0;
 
-static volatile union {
+static union {
        uint8_t u8;
        struct {
                /* inverted: little endian */
@@ -133,7 +141,7 @@ 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();
 
@@ -141,7 +149,7 @@ static void do_one_servo(struct servo *s)
        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();
 }
@@ -150,17 +158,26 @@ int main(void)
 {
        uint8_t i;
        uint8_t t, diff;
+       uint8_t tmp;
 
        /* LED */
-       DDRB = 0x20;
+       DDRB = 0x02;
 
-       /* servo outputs */
-       DDRD = 0xf8;
-       DDRB |= 0x01;
+#if 0 /* LED debug */
+       while (1) {
+               LED_ON();
+               wait_ms(100);
+               LED_OFF();
+               wait_ms(100);
+       }
+#endif
+
+       /* servo outputs PD2-PD7 */
+       DDRD = 0xfc;
 
-       /* start timer1 at clk/1 (8Mhz) */
+       /* start timer1 at clk/8 (1Mhz) */
        TCNT1 = 0;
-       TCCR1B = _BV(CS10);
+       TCCR1B = _BV(CS11);
 
        /* start timer0 at clk/1024 (~8Khz) */
        TCNT0 = 0;
@@ -171,7 +188,7 @@ int main(void)
 
        sei();
 
-       bypass = 1;
+       bypass = 0;
        while (1) {
                t = TCNT0;
                for (i = 0; i < NB_SERVO; i++) {
@@ -185,9 +202,17 @@ int main(void)
                        poll_spi();
                }
                /* bypass mode */
-               while (bypass == 1) {
-                       PORTD = ((PINC & 0x0f) << 3) | ((PINB & 0x01) << 7);
-                       poll_spi();
+               if (bypass == 1) {
+                       LED_ON();
+
+                       while (bypass == 1) {
+                               tmp = PINC;
+                               tmp &= 0x3f;
+                               tmp <<= 2;
+                               PORTD = tmp;
+                               poll_spi();
+                       }
+                       LED_OFF();
                }
        }