Merge pull request #1819 from PX4/chan16

Support 16 channels on IO via S.BUS

src/modules/px4iofirmware/mixer.cpp

@@ -272,8 +272,9 @@ mixer_tick(void)
 
 	if (mixer_servos_armed && should_arm) {
 		/* update the servo outputs. */
-		for (unsigned i = 0; i < PX4IO_SERVO_COUNT; i++)
+		for (unsigned i = 0; i < PX4IO_SERVO_HARDWARE_COUNT; i++) {
 			up_pwm_servo_set(i, r_page_servos[i]);
+		}
 
 		/* set S.BUS1 or S.BUS2 outputs */
 
@@ -285,8 +286,9 @@ mixer_tick(void)
 
 	} else if (mixer_servos_armed && should_always_enable_pwm) {
 		/* set the disarmed servo outputs. */
-		for (unsigned i = 0; i < PX4IO_SERVO_COUNT; i++)
+		for (unsigned i = 0; i < PX4IO_SERVO_HARDWARE_COUNT; i++) {
 			up_pwm_servo_set(i, r_page_servo_disarmed[i]);
+		}
 
 		/* set S.BUS1 or S.BUS2 outputs */
 		if (r_setup_features & PX4IO_P_SETUP_FEATURES_SBUS1_OUT)

src/modules/px4iofirmware/px4io.h

@@ -51,7 +51,8 @@
 /*
  * Constants and limits.
  */
-#define PX4IO_SERVO_COUNT		8
+#define PX4IO_SERVO_COUNT		16
+#define PX4IO_SERVO_HARDWARE_COUNT	8
 #define PX4IO_CONTROL_CHANNELS		8
 #define PX4IO_CONTROL_GROUPS		4
 #define PX4IO_RC_INPUT_CHANNELS		18

src/modules/px4iofirmware/registers.c

@@ -284,7 +284,7 @@ registers_set(uint8_t page, uint8_t offset, const uint16_t *values, unsigned num
 	case PX4IO_PAGE_DIRECT_PWM:
 
 		/* copy channel data */
-		while ((offset < PX4IO_CONTROL_CHANNELS) && (num_values > 0)) {
+		while ((offset < PX4IO_SERVO_COUNT) && (num_values > 0)) {
 
 			/* XXX range-check value? */
 			if (*values != PWM_IGNORE_THIS_CHANNEL) {

src/modules/px4iofirmware/sbus.c

@@ -163,8 +163,8 @@ sbus1_output(uint16_t *values, uint16_t num_values)
 void
 sbus2_output(uint16_t *values, uint16_t num_values)
 {
-	char b = 'B';
-	write(sbus_fd, &b, 1);
+	// XXX S.BUS2 is not implemented, fall back to S.BUS1
+	sbus1_output(values, num_values);
 }
 
 bool