UAVCAN max instances for sensors/devices

owen487 · March 26, 2025, 9:34am

I have a setup with 8 ark CAN nodes all with various sensors attached and am trying to get all instances down to QGC. It appears that the max number of instances for any one sensor/topic is 4. Where can I find the code that determines this.
If it is relevant - these are custom messages/topics that I have written (in case this is something produced by me)

dakejahl · March 27, 2025, 8:10pm

github.com/PX4/PX4-Autopilot

src/drivers/uavcan/sensors/sensor_bridge.hpp

7cb797726


      
          * This is the base class for redundant sensors with an independent ORB topic per each redundancy channel.
          * For example, sensor_mag0, sensor_mag1, etc.
          */
          class UavcanSensorBridgeBase : public IUavcanSensorBridge, public device::Device
          {
          	const orb_id_t _orb_topic;
          	uavcan_bridge::Channel *const _channels;
          	bool _out_of_channels = false;
          
          protected:
          	static constexpr unsigned DEFAULT_MAX_CHANNELS = 4;
          	const unsigned _max_channels;
          
          	UavcanSensorBridgeBase(const char *name, const orb_id_t orb_topic_sensor,
          			       const unsigned max_channels = DEFAULT_MAX_CHANNELS) :
          		Device(name),
          		_orb_topic(orb_topic_sensor),
          		_channels(new uavcan_bridge::Channel[max_channels]),
          		_max_channels(max_channels)
          	{
          		set_device_bus_type(DeviceBusType_UAVCAN);