#include <aversive.h>
#include <aversive/wait.h>
-#include <scheduler.h>
+#include <callout.h>
#include "spi_servo.h"
#include "main.h"
* callback is unloaded.
*/
-/* 1ms */
-#define SPI_EVT_PERIOD (10000UL/SCHEDULER_UNIT)
+#define PPM_BIT 0x01
+#define BYPASS_BIT 0x02
-#define N_SERVO 6
-#define BYPASS_ENABLE 14
-#define BYPASS_DISABLE 15
struct spi_servo_tx {
- uint16_t servo[N_SERVO];
+ uint16_t servo[N_SERVO+1]; /* one more for control channel */
uint16_t cmd_mask;
uint8_t next_byte; /* next byte to send, 0 if nothing in pipe */
uint8_t cur_idx;
};
static struct spi_servo_rx spi_servo_rx;
+static struct callout spi_timer;
+
/*
* SPI protocol:
*
* second one to 1. The first received byte contains the command number, and the
* msb of the servo value. The second byte contains the lsb of the servo value.
*
- * Commands 0 to NB_SERVO are to set the value of servo.
- * Command 14 is to enable bypass mode.
- * Command 15 is to disable bypass mode.
+ * Command 0 is only one byte long, it means "I have nothing to say".
+ * Commands 1 to N_SERVO (included) are to set the value of servo.
+ * Command N_SERVO+1 is:
+ * - to enable/disable ppm generation in place of last servo.
+ * - to enable/disable bypass mode
*/
union spi_byte0 {
uint8_t u8;
union spi_byte1 byte1;
byte0.val_msb = val >> 7;
- if (num < N_SERVO)
- byte0.cmd_num = num + 1;
- else
- byte0.cmd_num = num;
+ byte0.cmd_num = num + 1;
byte0.zero = 0;
byte1.one = 1;
byte1.val_lsb = val;
}
/* called by the scheduler */
-static void spi_servo_cb(void *arg)
+static void spi_servo_cb(struct callout_mgr *cm, struct callout *tim, void *arg)
{
uint8_t idx;
union spi_byte0 byte0;
if (spi_servo_tx.next_byte != 0) {
spi_send_byte(spi_servo_tx.next_byte);
spi_servo_tx.next_byte = 0;
- return;
+ goto reschedule;
}
/* if there is no updated servo, send 0 and return. */
if (spi_servo_tx.cmd_mask == 0) {
spi_send_byte(0);
- return;
+ goto reschedule;
}
/* else find it and send it */
idx = spi_servo_tx.cur_idx;
while (1) {
idx++;
- if (idx == N_SERVO)
- idx = BYPASS_ENABLE;
- else if (idx >= sizeof(uint16_t) * 8)
+ if (idx > N_SERVO + 1)
idx = 0;
if (spi_servo_tx.cmd_mask & (1 << (uint16_t)idx))
spi_send_one_servo(idx, spi_servo_tx.servo[idx]);
spi_servo_tx.cmd_mask &= (~(1 << idx));
spi_servo_tx.cur_idx = idx;
+
+ reschedule:
+ /* don't use callout_reschedule() here, we want to schedule in one tick
+ * relative to current time: 1 tick is 682us at 12Mhz */
+ callout_schedule(cm, tim, 0);
}
void spi_servo_init(void)
/* remove power reduction on spi */
PRR0 &= ~(1 << PRSPI);
- /* Enable SPI, Master, set clock rate fck/64 */
- SPCR = (1<<SPE)|(1<<MSTR)|(1<<SPR1);
+ /* Enable SPI, Master, set clock rate fck/16 */
+ SPCR = (1<<SPE)|(1<<MSTR)|(1<<SPR0);
SS_HIGH();
- scheduler_add_periodical_event_priority(&spi_servo_cb, NULL,
- SPI_EVT_PERIOD, SPI_PRIO);
- spi_servo_set(BYPASS_DISABLE, 0);
+ callout_init(&spi_timer, spi_servo_cb, NULL, SPI_PRIO);
+ callout_schedule(&xbeeboard.intr_cm, &spi_timer, 0); /* immediate */
+ spi_servo_set_bypass(1);
}
void spi_servo_set(uint8_t num, uint16_t val)
return val;
}
-void spi_servo_bypass(uint8_t enable)
+uint8_t spi_servo_get_bypass(void)
+{
+ return !!(spi_servo_tx.servo[N_SERVO] & BYPASS_BIT);
+}
+
+uint8_t spi_servo_get_ppm(void)
+{
+ return !!(spi_servo_tx.servo[N_SERVO] & PPM_BIT);
+}
+
+void spi_servo_set_bypass(uint8_t enable)
{
uint8_t flags;
- if (enable) {
- IRQ_LOCK(flags);
- spi_servo_tx.cmd_mask |= (1 << BYPASS_ENABLE);
- IRQ_UNLOCK(flags);
- }
- else {
- IRQ_LOCK(flags);
- spi_servo_tx.cmd_mask |= (1 << BYPASS_DISABLE);
- IRQ_UNLOCK(flags);
- }
+ IRQ_LOCK(flags);
+ spi_servo_tx.cmd_mask |= (1 << N_SERVO);
+ if (enable)
+ spi_servo_tx.servo[N_SERVO] |= BYPASS_BIT;
+ else
+ spi_servo_tx.servo[N_SERVO] &= (~BYPASS_BIT);
+ spi_servo_tx.cmd_mask |= (1 << N_SERVO);
+ IRQ_UNLOCK(flags);
+}
+
+void spi_servo_set_ppm(uint8_t enable)
+{
+ uint8_t flags;
+
+ IRQ_LOCK(flags);
+ spi_servo_tx.cmd_mask |= (1 << N_SERVO);
+ if (enable)
+ spi_servo_tx.servo[N_SERVO] |= PPM_BIT;
+ else
+ spi_servo_tx.servo[N_SERVO] &= (~PPM_BIT);
+ spi_servo_tx.cmd_mask |= (1 << N_SERVO);
+ IRQ_UNLOCK(flags);
+}
+
+void spi_servo_dump(void)
+{
+ uint8_t i;
+
+ for (i = 0; i < N_SERVO; i++)
+ printf_P(PSTR("%d: rx=%4.4d tx=%4.4d\r\n"), i,
+ spi_servo_get(i), spi_servo_tx.servo[i]);
+ printf_P(PSTR("bypass=%d ppm=%d\n"),
+ spi_servo_get_bypass(), spi_servo_get_ppm());
}