Holybro x500 v2 with Radiomaster Boxer and RP4TD

Hardware Pixhawk family
1

Hi everyone,

I’m having trouble getting past the ESC calibration and motor test stages on my Holybro X500 v2 kit.

Setup:

  • Flight controller: Pixhawk 6C

  • Transmitter: Radiomaster Boxer (ExpressLRS 2.4 GHz)

  • Receiver: RadioMaster RP4TD

  • Firmware: ArduPilot Copter

Here’s what happens:

  • The ESC calibration and motor tests work perfectly when I use PX4.

  • However, PX4 doesn’t seem to support ExpressLRS (CRSF protocol) yet.

  • When I switch to ArduPilot, the motors show no sign of life during calibration or testing.

I’ve ruled out wiring or hardware issues because everything works fine with PX4.

Has anyone managed to get this exact setup working under ArduPilot? Any tips, parameter files (.param), or verified configuration examples for this combination would be greatly appreciated.

Thanks in advance!

2

For PX4 see CRSF Telemetry (TBS Crossfire Telemetry) | PX4 Guide (main)

In Ardupilot CRSF is supported on all boards natively.

3

Thank you, Lupus. It would be preferable for me to continue with Ardupilot. The transmitter and receiver are working fine on ExpressLRS in Ardupilot. I can even calibrate the remote control on Mission Planner. The problem comes when I try to calibrate the ESCs and test the motors: nothing happens.

4

We have a Wiki page for that Electronic Speed Controller (ESC) Calibration — Copter documentation

5

Thank you. I tried that twice already. There is something wrong in my params I guess.

6

Post the parameter file. What ESC’s do you have?

7

I found out that the problem was that I was not calibrating the ESCs properly before testing the motors. First I made small adjustments to the parms on the ArduPilot V4.6.3 firmware for Holybro x500 v2 and also in the configuration of my Radio Master Boxer Express ELRS. Then I followed the ESC calibration instructions in Mission Planner step by step and the calibration worked (heard all the beeps). Then I tested the motors and it also worked. Changes to parms are listed below and my full specs (drone, radio, receiver, battery, ESCs, motors, propellers, etc.) at the bottom:

FRAME_CLASS = 1 (was 0)

Default is “Undefined” - must set to “Quad” or motors won’t work

SERIAL3_PROTOCOL = 23 (was 5)

Set to RCIN for CRSF receiver on TELEM3 port

Adjusted serial port number based on where my receiver is connected

RSSI_TYPE = 3 (ReceiverProtocol)

Enables RSSI telemetry from CRSF

FLTMODE_CH = 6 (not 5!)

ELRS Channel 5 (AUX1) is 2-position only (arm switch)

Use Channel 6 (AUX2) for 3-position flight mode switch

In the Radio Master Boxer Input menu I changed the SC switch to Channel 6.

I uploaded the params for reference.

Full Specs:

Airframe: Holybro X500 V2 (Quad X)
Carbon fiber frame, landing gear, GPS mast

Flight Controller: Pixhawk 6C

External compass: M10 (primary)

Power System:
Holybro PM02 V3 power module
XT60 battery input
XT30 ESC outputs
Battery: 4S LiPo 5200mAh 50C
Motors / ESC / Props:
Motors: Holybro 2216 KV920

ESC: BLHeli-S 20A

Props: 1045 (10x4.5), 2×CW / 2×CCW

Motor order: M1 FL (CW), M2 FR (CCW), M3 RR (CW), M4 RL (CCW)

GPS + Compass: Holybro M10 GNSS + IST8310 compass
Mounted on mast

Radio (TX):
Radiomaster Boxer ELRS (EdgeTX)
Internal ELRS 2.4GHz module (100 mW)
Basic 4-channel setup (no mode switch)

Receiver (RX): RadioMaster RP4TD (ELRS 2.4GHz, true diversity)
Protocol: CRSF

Wiring: 5V, GND, TX↔RX, RX↔TX

ELRS settings: Hybrid Switch Mode, 100–150 Hz rate

Telemetry: SiK Telemetry Radio V3 on TELEM port

Holybro_X500_V2_RMBoxer_RP4TD_param.param (18.9 KB)