Add back CANNODE_NODE_ID for setting a static node ID

docs/en/dronecan/ark_cannode.md

@@ -83,9 +83,10 @@ This is done using the the parameters named like `UAVCAN_SUB_*` in the parameter
 
 On the ARK CANnode, you may need to configure the following parameters:
 
-| Parameter                                                                                       | Description                   |
-| ----------------------------------------------------------------------------------------------- | ----------------------------- |
-| <a id="CANNODE_TERM"></a>[CANNODE_TERM](../advanced_config/parameter_reference.md#CANNODE_TERM) | CAN built-in bus termination. |
+| Parameter                                                                                             | Description                                                                                                                                        |
+| ----------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- |
+| <a id="CANNODE_NODE_ID"></a>[CANNODE_NODE_ID](../advanced_config/parameter_reference.md#CANNODE_NODE_ID) | CAN node ID (0 for dynamic allocation). If set to 0 (default), dynamic node allocation is used. Set to 1-127 to use a static node ID.            |
+| <a id="CANNODE_TERM"></a>[CANNODE_TERM](../advanced_config/parameter_reference.md#CANNODE_TERM)       | CAN built-in bus termination.                                                                                                                      |
 
 ## LED Meanings
 

docs/en/dronecan/ark_flow.md

@@ -110,9 +110,10 @@ When optical flow is the only source of horizontal position/velocity, then lower
 
 On the ARK Flow, you may need to configure the following parameters:
 
-| Parameter                                                                                       | Description                   |
-| ----------------------------------------------------------------------------------------------- | ----------------------------- |
-| <a id="CANNODE_TERM"></a>[CANNODE_TERM](../advanced_config/parameter_reference.md#CANNODE_TERM) | CAN built-in bus termination. |
+| Parameter                                                                                             | Description                                                                                                                                        |
+| ----------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- |
+| <a id="CANNODE_NODE_ID"></a>[CANNODE_NODE_ID](../advanced_config/parameter_reference.md#CANNODE_NODE_ID) | CAN node ID (0 for dynamic allocation). If set to 0 (default), dynamic node allocation is used. Set to 1-127 to use a static node ID.            |
+| <a id="CANNODE_TERM"></a>[CANNODE_TERM](../advanced_config/parameter_reference.md#CANNODE_TERM)       | CAN built-in bus termination.                                                                                                                      |
 
 ## LED Meanings
 

docs/en/dronecan/ark_flow_mr.md

@@ -105,9 +105,10 @@ Set the following parameters in _QGroundControl_:
 
 You may need to [configure the following parameters](../dronecan/index.md#qgc-cannode-parameter-configuration) on the ARK Flow MR itself:
 
-| Parameter                                                                                       | Description                   |
-| ----------------------------------------------------------------------------------------------- | ----------------------------- |
-| <a id="CANNODE_TERM"></a>[CANNODE_TERM](../advanced_config/parameter_reference.md#CANNODE_TERM) | CAN built-in bus termination. |
+| Parameter                                                                                             | Description                                                                                                                                        |
+| ----------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- |
+| <a id="CANNODE_NODE_ID"></a>[CANNODE_NODE_ID](../advanced_config/parameter_reference.md#CANNODE_NODE_ID) | CAN node ID (0 for dynamic allocation). If set to 0 (default), dynamic node allocation is used. Set to 1-127 to use a static node ID.            |
+| <a id="CANNODE_TERM"></a>[CANNODE_TERM](../advanced_config/parameter_reference.md#CANNODE_TERM)       | CAN built-in bus termination.                                                                                                                      |
 
 ## LED Meanings
 

docs/en/dronecan/ark_gps.md

@@ -91,9 +91,17 @@ If the sensor is not centred within the vehicle you will also need to define sen
 
 - Enable GPS yaw fusion by setting bit 3 of [EKF2_GPS_CTRL](../advanced_config/parameter_reference.md#EKF2_GPS_CTRL) to true.
 - Enable [UAVCAN_SUB_GPS](../advanced_config/parameter_reference.md#UAVCAN_SUB_GPS), [UAVCAN_SUB_MAG](../advanced_config/parameter_reference.md#UAVCAN_SUB_MAG), and [UAVCAN_SUB_BARO](../advanced_config/parameter_reference.md#UAVCAN_SUB_BARO).
-- Set [CANNODE_TERM](../advanced_config/parameter_reference.md#CANNODE_TERM) to `1` if this is that last node on the CAN bus.
 - The parameters [EKF2_GPS_POS_X](../advanced_config/parameter_reference.md#EKF2_GPS_POS_X), [EKF2_GPS_POS_Y](../advanced_config/parameter_reference.md#EKF2_GPS_POS_Y) and [EKF2_GPS_POS_Z](../advanced_config/parameter_reference.md#EKF2_GPS_POS_Z) can be set to account for the offset of the ARK GPS from the vehicles centre of gravity.
 
+### ARK GPS Configuration
+
+You may need to [configure the following parameters](../dronecan/index.md#qgc-cannode-parameter-configuration) on the ARK GPS itself:
+
+| Parameter                                                                                             | Description                                                                                                                                        |
+| ----------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- |
+| <a id="CANNODE_NODE_ID"></a>[CANNODE_NODE_ID](../advanced_config/parameter_reference.md#CANNODE_NODE_ID) | CAN node ID (0 for dynamic allocation). If set to 0 (default), dynamic node allocation is used. Set to 1-127 to use a static node ID.            |
+| <a id="CANNODE_TERM"></a>[CANNODE_TERM](../advanced_config/parameter_reference.md#CANNODE_TERM)       | CAN built-in bus termination. Set to `1` if this is the last node on the CAN bus.                                                                 |
+
 ## LED Meanings
 
 You will see green, blue and red LEDs on the ARK GPS when it is being flashed, and a blinking green LED if it is running properly.

docs/en/dronecan/ark_rtk_gps.md

@@ -85,7 +85,15 @@ You need to set necessary [DroneCAN](index.md) parameters and define offsets if
 - Enable GPS blending to ensure the heading is always published by setting [SENS_GPS_MASK](../advanced_config/parameter_reference.md#SENS_GPS_MASK) to 7 (all three bits checked).
 - Enable [UAVCAN_SUB_GPS](../advanced_config/parameter_reference.md#UAVCAN_SUB_GPS), [UAVCAN_SUB_MAG](../advanced_config/parameter_reference.md#UAVCAN_SUB_MAG), and [UAVCAN_SUB_BARO](../advanced_config/parameter_reference.md#UAVCAN_SUB_BARO).
 - The parameters [EKF2_GPS_POS_X](../advanced_config/parameter_reference.md#EKF2_GPS_POS_X), [EKF2_GPS_POS_Y](../advanced_config/parameter_reference.md#EKF2_GPS_POS_Y) and [EKF2_GPS_POS_Z](../advanced_config/parameter_reference.md#EKF2_GPS_POS_Z) can be set to account for the offset of the ARK RTK GPS from the vehicles centre of gravity.
-- Set [CANNODE_TERM](../advanced_config/parameter_reference.md#CANNODE_TERM) to `1` on the GPS if this it that last node on the CAN bus.
+
+### ARK RTK GPS Configuration
+
+You may need to [configure the following parameters](../dronecan/index.md#qgc-cannode-parameter-configuration) on the ARK RTK GPS itself:
+
+| Parameter                                                                                             | Description                                                                                                                                        |
+| ----------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- |
+| <a id="CANNODE_NODE_ID"></a>[CANNODE_NODE_ID](../advanced_config/parameter_reference.md#CANNODE_NODE_ID) | CAN node ID (0 for dynamic allocation). If set to 0 (default), dynamic node allocation is used. Set to 1-127 to use a static node ID.            |
+| <a id="CANNODE_TERM"></a>[CANNODE_TERM](../advanced_config/parameter_reference.md#CANNODE_TERM)       | CAN built-in bus termination. Set to `1` if this is the last node on the CAN bus.                                                                 |
 
 ### Setting Up Rover and Fixed Base
 

docs/en/dronecan/index.md

@@ -96,6 +96,10 @@ If the DNA is still running and certain devices need to be manually configured,
 ::: info
 The PX4 node ID can be configured using the [UAVCAN_NODE_ID](../advanced_config/parameter_reference.md#UAVCAN_NODE_ID) parameter.
 The parameter is set to 1 by default.
+
+Devices running the [PX4 DroneCAN firmware](px4_cannode_fw.md) (such as [ARK CANnode](ark_cannode.md)) can use the
+[CANNODE_NODE_ID](../advanced_config/parameter_reference.md#CANNODE_NODE_ID) parameter to set a static node ID.
+Set it to 0 (default) for dynamic allocation, or to a value between 1-127 to use a specific static node ID.
 :::
 
 :::warning
@@ -282,6 +286,11 @@ For example, the screenshot below shows the parameters for a CAN GPS with node i
 
 ![QGC Parameter showing selected DroneCAN node](../../assets/can/dronecan/qgc_can_parameters.png)
 
+Common CANNODE parameters that you can configure include:
+
+- [CANNODE_NODE_ID](../advanced_config/parameter_reference.md#CANNODE_NODE_ID): Set a static node ID (1-127) or use 0 for dynamic allocation. See [PX4 DroneCAN Firmware > Static Node ID](px4_cannode_fw.md#static-node-id) for more information.
+- [CANNODE_TERM](../advanced_config/parameter_reference.md#CANNODE_TERM): Enable CAN bus termination on the last node in the bus.
+
 ## Device Specific Setup
 
 Most DroneCAN nodes require no further setup, unless specifically noted in their device-specific documentation.

docs/en/dronecan/px4_cannode_fw.md

@@ -20,6 +20,26 @@ make ark_can-flow_default
 
 This will create an output in **build/ark_can-flow_default** named **XX-X.X.XXXXXXXX.uavcan.bin**. Follow the instructions at [DroneCAN firmware update](index.md#firmware-update) to flash the firmware.
 
+## Configuration
+
+### Static Node ID
+
+By default, DroneCAN devices use [Dynamic Node Allocation (DNA)](index.md#node-id-allocation) to automatically obtain a unique node ID from the flight controller.
+However, you can configure a static node ID using the [CANNODE_NODE_ID](../advanced_config/parameter_reference.md#CANNODE_NODE_ID) parameter.
+
+To configure a static node ID:
+
+1. Set [CANNODE_NODE_ID](../advanced_config/parameter_reference.md#CANNODE_NODE_ID) to a value between 1-127 using [QGroundControl](index.md#qgc-cannode-parameter-configuration)
+2. Reboot the device
+
+To return to dynamic allocation, set `CANNODE_NODE_ID` back to 0.
+Note that when switching back to dynamic allocation, the flight controller will typically continue to allocate the same node ID that was previously used (this is normal DNA behavior).
+
+:::warning
+When using static node IDs, you must ensure that each device on the CAN bus has a unique node ID.
+Configuring two devices with the same ID will cause communication conflicts.
+:::
+
 ## Developer Information
 
 This section has information that is relevant to developers who want to add support for new DroneCAN hardware to the PX4 Autopilot.

src/drivers/uavcannode/UavcanNode.cpp

@@ -824,6 +824,27 @@ extern "C" int uavcannode_start(int argc, char *argv[])
 		}
 	}
 
+	// Read the static node ID parameter and use it if no valid node_id from shared memory
+	int32_t cannode_node_id = 0;
+	param_get(param_find("CANNODE_NODE_ID"), &cannode_node_id);
+
+	// Check if the static node ID is in range
+	if (cannode_node_id < 0 || cannode_node_id > 127) {
+		PX4_ERR("Invalid static node ID %ld, using dynamic allocation", cannode_node_id);
+		cannode_node_id = 0;
+	}
+
+	// Assign the static node ID if no dynamic allocation is used. Do wen't override a valid node ID from the bootloader?
+	if (node_id == 0 && cannode_node_id > 0 && cannode_node_id <= 127) {
+		node_id = cannode_node_id;
+	}
+
+	// Persist the node ID for the bootloader
+	bootloader_app_shared_t shared_write = {};
+	shared_write.node_id = node_id;
+	shared_write.bus_speed = bitrate;
+	bootloader_app_shared_write(&shared_write, BootLoader);
+
 	if (
 #if defined(SUPPORT_ALT_CAN_BOOTLOADER)
 		board_booted_by_px4() &&

src/drivers/uavcannode/uavcannode_params.c

@@ -31,6 +31,15 @@
  *
  ****************************************************************************/
 
+/**
+ * UAVCAN CAN node ID (0 for dynamic allocation).
+ *
+ * @min 0
+ * @max 127
+ * @group UAVCAN
+ */
+PARAM_DEFINE_INT32(CANNODE_NODE_ID, 0);
+
 /**
  * UAVCAN CAN bus bitrate.
  *