The Here+ RTK GPS receiver is a small, light and energy efficient RTK GPS module, based on the u-blox M8P. Using RTK, PX4 can get its position with centimetre-level accuracy, which is much more accurate than can be provided by a normal GPS.
RTK setup and use on PX4 via QGroundControl is largely plug and play (see RTK GPS for more information).
The Here+ GPS comes with an 8 pin connector with the following pinout
|4 (yellow)||I2C SCL|
|5 (orange)||I2C SDA|
|6 (red)||SAFETY BUTTON|
Connection examples are shown below for a number of boards (these can be used to modify the cable as needed for other boards).
The supplied cable can be inserted directly into the Hex Cube (Pixhawk 2) GPS UART port.
Pin 6 and 7 are for the safety button - these can be attached as well if needed.
|Pin||Here+ GPS||Pin||Pixhawk 3 Pro GPS|
The Here+ to Pixhawk 4 GPS port pin mapping is 1:1 for pins 1-7 and then connect GND (Here+ pin 8 / Pixhawk pin 10). Pixhawk 4 GPS port pins 8 and 9 can be left disconnected.
The Pixhawk 4 GPS port has pin 1 on the left hand side.
|Pin||Here+ GPS||pin||Pixhawk 4 GPS Port|