OSD Configuration and Testing

Owned by Ayush Ganguly
Last updated: 2024-03-09
3 min read

OSD Harness and Video System

The Holybro OSD is a COTS board with a MAX7456 monochrome OSD chip. It is used the display the telemetry data to your First Person View (FPV) transmitter or goggles.

Following is a snapshot of the architecture of how we connect the OSD to Pegasus.

Notes:

  • The Battery in the OSD board should get 12V and this is used to power the VTX and FPV cameras.

  • The OSD itself gets 5V power from the Ardupilot telemetry port.

 

OSD Configuration

This can be done by connecting the Telemetry port via an FTDI cable to your laptop. Make sure that the battery ports are disconnected/ the power on the drone is not on. We can use the RTS port instead of the DTR port if your FTDI adapter does not have DTR. Remember to connect the TXD of FTDI to the RXD of the OSD board and vice versa.

We use the OSD Config tool to configure the elements that are required as per the flight pilots. Download this zip file, and run the OSD_config.exe program with the COM port, your FTDI is connected to.

Here is an example of the Configuration of the tool and 2 screens it supports:

 

 

Note: Set up the OSD video mode to PAL/NTSC depending on what video analog stream that your FPV outputting.

Configure Parameters at Ardupilot

Set the Serial Protocol Communication to MAVLINK 1 as the OSD does not understand MAVLINK 2 signals and Baud rate to 57500 of the telemetry port the OSD is connected to.

Below is a screenshot showing the OSD configured to Telem 1

 

For testing the OSD overlay on your video transmitter, we need to power on the drone + video transmitter system.

  • First test two 6S batteries with a battery meter and make sure that the voltage level per cell is 3.3V.

  • Also, test the 4S battery with the battery meter, and make sure the voltage per cell is 3.3V too, you will need this for the VTX tracker, and also the power the VTX LCD

  • Connect two batteries to the two XT60 ports on the drone, then connect the non-antispark power line, and finally connect the XT90 anti-spark connector (green labeled) to complete the circuit

  • When testing batteries, please check the battery every once in a while as the drone can drain the battery below critical. It should be above 3.3V level voltage per cell.

  • Once Pegasus is powered on, power on the video transmitter and select channel A-1 to see the OSD overlay on the FPV view.