# CUAV C-RTK

The CUAV C-RTK GPS receiver (opens new window) is an RTK GPS module module for mass market launched by CUAV. A complete RTK system consists of at least two C-RTK modules (one for the base station and the others for the aircraft). Using RTK, PX4 can get its position with centimetre-level accuracy, which is much more accurate than can be provided by a normal GPS.

# Purchase

# Configuration

RTK setup and use on PX4 via QGroundControl is largely plug and play (see RTK GPS for more information).

# Wiring and Connections

C-RTK GPS comes with a cable that terminates in a 6-pin connector and 4-pin connector that are compatible with Pixhack v3 (opens new window). The 6-pin connector provides the interface for RTK GPS, and should be connected to the flight controller's GPS port. The 4-pin connector is an m8n (standard) GPS interface that is intended for (optional) use as a second GPS.

Tip At time of writing PX4 does not yet fully support a second GPS. The 4-pin port need not be connected.

The cables/connectors may need to be modified in order to connect to other flight controller boards. The pin mappings for Pixhawk 3 Pro and Pixracer are shown below.

# Pinout

The C-RTK GPS pinout is provided below. This can be used to help modify the connector for other autopilot boards.

pin C-RTK GPS 6P pin Pixhawk 3 Pro GPS C-RTK GPS 4P
1 SDA 1 VCC
2 SCL 2 GPS_TX
3 GPS_RX 3 GPS_RX GPS_RX
4 GPS_TX 4 SCL GPS_TX
5 VCC_5V 5 SDA VCC_5v
6 GND 6 GND GND