MAVLink OSD with Matek H743

A guide for using the Matek H743 in conjunction with a Cube Orange+ to provide an analog OSD

Flashed with a custom ArduPilot build, we can use a Matek flight controller to draw the OSD on an analog video feed using MAVLink telemetry data from a Cube Orange+ rather than its own internal information. We use this internally because the Cube Orange+ does not support this kind of OSD, nor does it have onboard 9V power.

Note that we hook up the VTX control pin to the Cube Orange+ so we can control the VTX power with the RC.

Custom ArduPilot build

The Matek needs a custom build of ArduPilot to display MAVLink telemetry data on the OSD. The Cube does not need custom firmware.

arduplane.apj

1MB

Open

Flash your Matek with this build, then configure the parameters as follows:

Parameter	Value	Purpose
SYSID_THISMAV	42	Gives the Matek a distinct MAVLink system ID
OSD_TYPE	1	Enables the onboard MAX7456/AT7456 analog OSD
OSD_REM_ENABLE	1	Enables remote MAVLink telemetry for OSD panels
OSD_REM_SYSID	1	Accepts telemetry from the Cube's MAVLink system ID
OSD_REM_TOUT	1500	Marks remote telemetry stale after 1500ms
SERIAL5_PROTOCOL	2	Enables MAVLink2 on the Matek TX8/RX8 port
SERIAL5_BAUD	57	Sets the Matek TX8/RX8 port to 57600 baud

Reboot the Matek after changing the parameters. You may use any serial port. I used TX8/RX8.

Cube Orange+ params

These params need to be changed on the Cube for this to work. You can use any two serial ports on the Cube, but you do need two separate serial ports, one sending telemetry data to the Matek and one to control the VTX.

Parameter	Value	Purpose
SERIAL2_PROTOCOL	2	MAVLink2 output on Cube TELEM2
SERIAL2_BAUD	57	57600 baud to match the Matek

Set the Cube stream rates for the telemetry port wired to the Matek. For TELEM2, use:

Parameter	Value	Purpose
SR2_EXT_STAT	5	Sends battery and system-status data
SR2_EXTRA1	10	Sends attitude and flight display data
SR2_EXTRA2	5	Sends additional flight telemetry
SR2_POSITION	5	Sends global position and altitude data
SR2_RAW_SENS	2	Sends GPS/sensor status data

Lastly, ensure the Cube is set up for VTX on:

Parameter	Value	Purpose
SERIAL3_PROTOCOL	37	Configure GPS1 serial UART to control the VTX
VTX_ENABLE	1	Enable VTX control from the Cube
RCx_OPTION	94	Map VTX control to an RC channel

You may need to also configure VTX_POWER and VTX_MAX_POWER to allow for correct power switching.