static struct servo servo_table[] = {
{
- .bit = 0,
+ .bit = 3,
.command = 0,
},
{
- .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))
-register uint8_t bypass asm("r2");
-register uint8_t done asm("r3");
-register uint8_t portval asm("r4");
-register uint8_t rxidx asm("r5");
+static volatile uint8_t bypass;
+static volatile uint8_t done;
+static volatile uint8_t portval;
+static volatile uint8_t rxidx;
+
+#define BYPASS_ENABLE 14
+#define BYPASS_DISABLE 15
/*
* SPI protocol:
* Command 14 is to enable bypass mode.
* Command 15 is to disable bypass mode.
*/
-register union {
+static volatile union {
uint8_t u8;
struct {
- uint8_t zero:1;
- uint8_t cmd_num:4;
+ /* inverted: little endian */
uint8_t val_msb:3;
+ uint8_t cmd_num:4;
+ uint8_t zero:1;
};
-} byte0 asm("r6");
+} byte0;
-register union {
+static volatile union {
uint8_t u8;
struct {
- uint8_t one:1;
+ /* inverted: little endian */
uint8_t val_lsb:7;
+ uint8_t one:1;
};
-} byte1 asm("r7");
+} byte1;
SIGNAL(TIMER1_COMPA_vect)
{
- PORTC = portval;
+ PORTD = portval;
TIMSK1 &= ~_BV(OCIE1A);
done = 1;
}
val += byte1.val_lsb;
servo_table[byte0.cmd_num].command = val;
}
- else if (byte0.cmd_num == 14) {
+ else if (byte0.cmd_num == BYPASS_ENABLE) {
bypass = 1;
}
- else if (byte0.cmd_num == 15) {
+ else if (byte0.cmd_num == BYPASS_DISABLE) {
bypass = 0;
}
}
DDRB = 0x20;
/* servo outputs */
- DDRC = 0x7;
+ DDRD = 0xf8;
+ DDRB |= 0x01;
/* start timer1 at clk/1 (8Mhz) */
TCNT1 = 0;
sei();
+ bypass = 1;
while (1) {
t = TCNT0;
for (i = 0; i < NB_SERVO; i++) {
}
/* bypass mode */
while (bypass == 1) {
- PORTC = PORTB;
+ PORTD = ((PINC & 0x0f) << 3) | ((PINB & 0x01) << 7);
+ poll_spi();
}
}