uavcan: handle all ESC output in one place

moving all the ESC output handling to one place allows the limits on
actuator values to apply to all types of inputs, and will make it
easier to expand "uavcan status" to show actuator values

src/modules/uavcan/uavcan_main.cpp

@@ -282,8 +282,7 @@ int UavcanNode::run()
 	_test_motor_sub = orb_subscribe(ORB_ID(test_motor));
 	_actuator_direct_sub = orb_subscribe(ORB_ID(actuator_direct));
 
-	actuator_outputs_s outputs;
-	memset(&outputs, 0, sizeof(outputs));
+	memset(&_outputs, 0, sizeof(_outputs));
 
 	const int busevent_fd = ::open(uavcan_stm32::BusEvent::DevName, 0);
 	if (busevent_fd < 0)
@@ -339,6 +338,8 @@ int UavcanNode::run()
 
 		node_spin_once();  // Non-blocking
 
+		bool new_output = false;
+
 		// this would be bad...
 		if (poll_ret < 0) {
 			log("poll error %d", errno);
@@ -360,58 +361,67 @@ int UavcanNode::run()
 			 */
 			if (_actuator_direct_sub != -1 && 
 			    (_poll_fds[_actuator_direct_poll_fd_num].revents & POLLIN) &&
-			    orb_copy(ORB_ID(actuator_direct), _actuator_direct_sub, &_actuator_direct) == OK) {
-				// Output to the bus
-				_esc_controller.update_outputs(_actuator_direct.values, _actuator_direct.nvalues);
+			    orb_copy(ORB_ID(actuator_direct), _actuator_direct_sub, &_actuator_direct) == OK &&
+			    !_test_in_progress) {
+				if (_actuator_direct.nvalues > NUM_ACTUATOR_OUTPUTS) {
+					_actuator_direct.nvalues = NUM_ACTUATOR_OUTPUTS;
+				}
+				memcpy(&_outputs.output[0], &_actuator_direct.values[0], 
+				       _actuator_direct.nvalues*sizeof(float));
+				_outputs.noutputs = _actuator_direct.nvalues;
+				new_output = true;
 			}
 
 			// can we mix?
 			if (_test_in_progress) {
-				float test_outputs[NUM_ACTUATOR_OUTPUTS] = {};
-				test_outputs[_test_motor.motor_number] = _test_motor.value*2.0f-1.0f;
-
-				// Output to the bus
-				_esc_controller.update_outputs(test_outputs, NUM_ACTUATOR_OUTPUTS);
+				memset(&_outputs, 0, sizeof(_outputs));
+				if (_test_motor.motor_number < NUM_ACTUATOR_OUTPUTS) {
+					_outputs.output[_test_motor.motor_number] = _test_motor.value*2.0f-1.0f;
+					_outputs.noutputs = _test_motor.motor_number+1;
+				}
+				new_output = true;
 			} else if (controls_updated && (_mixers != nullptr)) {
 
 				// XXX one output group has 8 outputs max,
 				// but this driver could well serve multiple groups.
 				unsigned num_outputs_max = 8;
 
 				// Do mixing
-				outputs.noutputs = _mixers->mix(&outputs.output[0], num_outputs_max);
-				outputs.timestamp = hrt_absolute_time();
-
-				// iterate actuators
-				for (unsigned i = 0; i < outputs.noutputs; i++) {
-					// last resort: catch NaN, INF and out-of-band errors
-					if (!isfinite(outputs.output[i])) {
-						/*
-						 * Value is NaN, INF or out of band - set to the minimum value.
-						 * This will be clearly visible on the servo status and will limit the risk of accidentally
-						 * spinning motors. It would be deadly in flight.
-						 */
-						outputs.output[i] = -1.0f;
-					}
+				_outputs.noutputs = _mixers->mix(&_outputs.output[0], num_outputs_max);
 
-					// limit outputs to valid range
+				new_output = true;
+			}
+		}
 
-					// never go below min
-					if (outputs.output[i] < -1.0f) {
-						outputs.output[i] = -1.0f;
-					}
+		if (new_output) {
+			// iterate actuators, checking for valid values
+			for (uint8_t i = 0; i < _outputs.noutputs; i++) {
+				// last resort: catch NaN, INF and out-of-band errors
+				if (!isfinite(_outputs.output[i])) {
+					/*
+					 * Value is NaN, INF or out of band - set to the minimum value.
+					 * This will be clearly visible on the servo status and will limit the risk of accidentally
+					 * spinning motors. It would be deadly in flight.
+					 */
+					_outputs.output[i] = -1.0f;
+				}
 
-					// never go below max
-					if (outputs.output[i] > 1.0f) {
-						outputs.output[i] = 1.0f;
-					}
+				// never go below min
+				if (_outputs.output[i] < -1.0f) {
+					_outputs.output[i] = -1.0f;
 				}
 
-				// Output to the bus
-				_esc_controller.update_outputs(outputs.output, outputs.noutputs);
+				// never go above max
+				if (_outputs.output[i] > 1.0f) {
+					_outputs.output[i] = 1.0f;
+				}
 			}
+			// Output to the bus
+			_outputs.timestamp = hrt_absolute_time();
+			_esc_controller.update_outputs(_outputs.output, _outputs.noutputs);
 		}
 
+
 		// Check motor test state
 		bool updated = false;
 		orb_check(_test_motor_sub, &updated);

src/modules/uavcan/uavcan_main.hpp

@@ -133,6 +133,8 @@ class UavcanNode : public device::CDev
 	uint8_t			_actuator_direct_poll_fd_num;
 	actuator_direct_s	_actuator_direct;
 
+	actuator_outputs_s	_outputs;
+
 	// index into _poll_fds for each _control_subs handle
 	uint8_t			_poll_ids[NUM_ACTUATOR_CONTROL_GROUPS_UAVCAN];
 };