I2C Display on Matek F405 - SE

Hi all,

I’m currently working with the flight controller found here, a Matek F405 SE, and running Arducopter 4.1.3. Ever since I saw this done a few years ago, I thought it was pretty handy feature, and so I am trying to use a small i2c display with this board for mode awareness/pre-arm failures, etc. However, I am having a hard time figuring out what I am doing wrong. I currently have this i2c display, which appears to be one of the compatible models on this wiki page. I have power and ground wired correctly, but I am trying to figure out where the SCL & SDA connections will go and/or how to configure them correctly in Mission Planner. Currently I have them connected SCL on the display going to CL2 and SDA going to DA2 on the F405, but am getting no response from the display even when applying full battery voltage to the board and after enabling the NTF_DISPLAY_TYPE parameter in Mission Planner. I don’t know what I might be missing. Thanks in advance for any advice.

I thought this might be a firmware issue, although the NTF_DISPLAY_TYPE was appearing even in the default firmware, so I tried creating a custom firmware here at custom.ardupilot.org, and selected the “display” option, creating the firmware here ArduPilot Custom Firmware Builder

I have flashed it to the flight controller, but the problem persists. I have two different i2c (same model) to test with, so I don’t think it is the display - now I’m wondering if there is some kind of board configuration I need to change to correctly output on the pads I soldered to, or if I am using the wrong pads in the first place.

Looking at the documentation on Matek’s Website, http://www.mateksys.com/?portfolio=f405-se#tab-id-5 it looks like this FC has support for a I2C OLED display in Betaflight and Inav, but perhaps not in Ardupilot. Is it possible to add this support? What would it require?

Update - upon finding others with similar issues, I thought I’d try a different I2C display. The one listed here Issue trying to connect I2C OLED display to Pixhawk - #10 by Erik_Groeneveld and here Issue trying to connect I2C OLED display to Pixhawk - #17 by rob215x both worked for me back on the non-custom firmware flashed to this board while only having to change the NTF_DISPLAY_TYPE parameter, as I had originally tried. No custom firmware was needed, just the right hardware! I don’t know enough about I2C to know why certain displays work and others do not, but it seems it might have something to do with the I2C “address” - from what I could gather that others were mentioning.