# PX4 Instructions ## Single GPS Configuration Connect the ARK TESEO GPS to the flight controller's CAN port using a standard 4-pin JST-GH cable. ### Flight Controller Parameters Set the following in *QGroundControl* and reboot the flight controller. #### Required | Parameter | Value | Description | | ------------------------------------------------------------------------------------------------------- | ----- | ----------------------------------------------- | | [UAVCAN\_ENABLE](https://docs.px4.io/main/en/advanced_config/parameter_reference.html#UAVCAN_ENABLE) | 2 | Enable DroneCAN with dynamic node allocation | | [UAVCAN\_SUB\_GPS](https://docs.px4.io/main/en/advanced_config/parameter_reference.html#UAVCAN_SUB_GPS) | 1 | Subscribe to DroneCAN GPS messages | | [UAVCAN\_SUB\_MAG](https://docs.px4.io/main/en/advanced_config/parameter_reference.html#UAVCAN_SUB_MAG) | 1 | Subscribe to DroneCAN magnetometer messages | | [EKF2\_GPS\_CTRL](https://docs.px4.io/main/en/advanced_config/parameter_reference.html#EKF2_GPS_CTRL) | 7 | Enable GPS fusion (lon/lat + alt + 3D velocity) | #### Optional | Parameter | Description | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------ | | [UAVCAN\_SUB\_BARO](https://docs.px4.io/main/en/advanced_config/parameter_reference.html#UAVCAN_SUB_BARO) | Set to `1` to subscribe to DroneCAN barometer messages | | [UAVCAN\_SUB\_IMU](https://docs.px4.io/main/en/advanced_config/parameter_reference.html#UAVCAN_SUB_IMU) | Set to `1` to subscribe to DroneCAN `RawIMU` messages | | [EKF2\_GPS\_POS\_X](https://docs.px4.io/main/en/advanced_config/parameter_reference.html#EKF2_GPS_POS_X) / [EKF2\_GPS\_POS\_Y](https://docs.px4.io/main/en/advanced_config/parameter_reference.html#EKF2_GPS_POS_Y) / [EKF2\_GPS\_POS\_Z](https://docs.px4.io/main/en/advanced_config/parameter_reference.html#EKF2_GPS_POS_Z) | GPS offset from the vehicle center of gravity (meters) | ### CAN Node Parameters Set the following on the GPS and reboot the node. CAN node parameters can be configured using either: * [QGroundControl](https://docs.px4.io/main/en/dronecan/#qgc-cannode-parameter-configuration) — each CAN node appears as a separate *Component X* entry under **Vehicle Settings > Parameters**. * The [DroneCAN GUI Tool](/knowledge-base/knowledge-base/dronecan-gui-tool-guide.md). #### Required | Parameter | Value | Description | | ----------------- | ----- | -------------------------------------------- | | `CANNODE_PUB_MAG` | 1 | Publish magnetometer messages on the CAN bus | #### Optional | Parameter | Description | | ------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `CANNODE_TERM` | Set to `1` if this is the last node on the CAN bus | | `CANNODE_PUB_BARO` | Set to `1` to publish barometer messages on the CAN bus | | `CANNODE_PUB_IMU` | Set to `1` to publish `RawIMU` messages on the CAN bus | | `TESEO_FWUPD` | Set to `1` to force the cannode to re-flash the embedded LIV4F firmware on the next boot. The cannode auto-updates the LIV4F whenever the embedded version differs from what is on the GPS chip — this parameter is only needed to force a re-flash without a version change. Auto-cleared back to `0` after a successful update | *** ## Constellation Selection The Teseo-LIV4F can track up to **four GNSS constellations simultaneously**. Enabling more than four has no effect — pick the four that match your operating region. SBAS does not count toward this limit. Configure these on the GPS using the same method as the [CAN Node Parameters](#can-node-parameters) above. | Parameter | Default | Description | | --------------- | ------- | ------------------------------------------------- | | `TESEO_GPS` | 1 | Enable the GPS (USA) constellation | | `TESEO_GLONASS` | 1 | Enable the GLONASS (Russia) constellation | | `TESEO_GALILEO` | 1 | Enable the Galileo (EU) constellation | | `TESEO_BEIDOU` | 1 | Enable the BeiDou (China) constellation | | `TESEO_QZSS` | 0 | Enable the QZSS (Japan) constellation | | `TESEO_IRNSS` | 0 | Enable the IRNSS / NavIC (India) constellation | | `TESEO_SBAS` | 1 | Enable SBAS (Satellite-Based Augmentation System) | *** ## Tuning EKF2\_REQ\_SACC The Teseo-LIV4F can report higher speed-accuracy values than the default [EKF2\_REQ\_SACC](https://docs.px4.io/main/en/advanced_config/parameter_reference.html#EKF2_REQ_SACC) threshold (0.5 m/s), causing PX4 to reject GPS fusion. Increasing `EKF2_REQ_SACC` to **1.5–2.0 m/s** is recommended for this module. *** ## Troubleshooting * See our [GPS Placement](/knowledge-base/knowledge-base/gps-placement.md) guide for mounting best practices, interference sources, and antenna positioning. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.arkelectron.com/products/gps/ark-teseo-gps/px4-instructions.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. 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