AP_UAVCAN: added logging of UAVCAN LogMessage messages

this allows us to log internal errors from nodes into main flight
controller log

libraries/AP_UAVCAN/AP_UAVCAN.cpp

@@ -41,6 +41,7 @@
 #include <ardupilot/indication/Button.hpp>
 #include <ardupilot/equipment/trafficmonitor/TrafficReport.hpp>
 #include <uavcan/equipment/gnss/RTCMStream.hpp>
+#include <uavcan/protocol/debug/LogMessage.hpp>
 
 #include <AP_Baro/AP_Baro_UAVCAN.h>
 #include <AP_RangeFinder/AP_RangeFinder_UAVCAN.h>
@@ -129,6 +130,10 @@ static uavcan::Subscriber<uavcan::equipment::actuator::Status, ActuatorStatusCb>
 UC_REGISTRY_BINDER(ESCStatusCb, uavcan::equipment::esc::Status);
 static uavcan::Subscriber<uavcan::equipment::esc::Status, ESCStatusCb> *esc_status_listener[HAL_MAX_CAN_PROTOCOL_DRIVERS];
 
+// handler DEBUG
+UC_REGISTRY_BINDER(DebugCb, uavcan::protocol::debug::LogMessage);
+static uavcan::Subscriber<uavcan::protocol::debug::LogMessage, DebugCb> *debug_listener[HAL_MAX_CAN_PROTOCOL_DRIVERS];
+
 AP_UAVCAN::esc_data AP_UAVCAN::_escs_data[];
 HAL_Semaphore AP_UAVCAN::_telem_sem;
 
@@ -302,6 +307,11 @@ void AP_UAVCAN::init(uint8_t driver_index, bool enable_filters)
     if (esc_status_listener[driver_index]) {
         esc_status_listener[driver_index]->start(ESCStatusCb(this, &handle_ESC_status));
     }
+
+    debug_listener[driver_index] = new uavcan::Subscriber<uavcan::protocol::debug::LogMessage, DebugCb>(*_node);
+    if (debug_listener[driver_index]) {
+        debug_listener[driver_index]->start(DebugCb(this, &handle_debug));
+    }
     
     _led_conf.devices_count = 0;
     if (enable_filters) {
@@ -871,4 +881,21 @@ bool AP_UAVCAN::is_esc_data_index_valid(const uint8_t index) {
     return true;
 }
 
+/*
+  handle LogMessage debug
+ */
+void AP_UAVCAN::handle_debug(AP_UAVCAN* ap_uavcan, uint8_t node_id, const DebugCb &cb)
+{
+#ifndef HAL_NO_LOGGING
+    const auto &msg = *cb.msg;
+    if (AP::can().get_log_level() != AP_CANManager::LOG_NONE) {
+        // log to onboard log and mavlink
+        GCS_SEND_TEXT(MAV_SEVERITY_INFO, "CAN[%u] %s", node_id, msg.text.c_str());
+    } else {
+        // only log to onboard log
+        AP::logger().Write_MessageF("CAN[%u] %s", node_id, msg.text.c_str());
+    }
+#endif
+}
+
 #endif // HAL_NUM_CAN_IFACES

libraries/AP_UAVCAN/AP_UAVCAN.h

@@ -56,6 +56,7 @@ class ButtonCb;
 class TrafficReportCb;
 class ActuatorStatusCb;
 class ESCStatusCb;
+class DebugCb;
 
 #if defined(__GNUC__) && (__GNUC__ > 8)
 #define DISABLE_W_CAST_FUNCTION_TYPE_PUSH \
@@ -241,12 +242,13 @@ private:
     // safety status send state
     uint32_t _last_safety_state_ms;
 
-    // safety button handling
+    // incoming button handling
     static void handle_button(AP_UAVCAN* ap_uavcan, uint8_t node_id, const ButtonCb &cb);
     static void handle_traffic_report(AP_UAVCAN* ap_uavcan, uint8_t node_id, const TrafficReportCb &cb);
     static void handle_actuator_status(AP_UAVCAN* ap_uavcan, uint8_t node_id, const ActuatorStatusCb &cb);
     static void handle_ESC_status(AP_UAVCAN* ap_uavcan, uint8_t node_id, const ESCStatusCb &cb);
     static bool is_esc_data_index_valid(const uint8_t index);
+    static void handle_debug(AP_UAVCAN* ap_uavcan, uint8_t node_id, const DebugCb &cb);
 };
 
 #endif // #if HAL_ENABLE_LIBUAVCAN_DRIVERS