ChibiOS 4.0.3 on Pixhawk 1

I’ve got a pixhawk 1 FC that has been running px4 pro 1.10.1. I’m trying to switch to Ardupilot chibios 4.0.3. However, once I flash to ardupilot, the FC won’t read ppm RC inputs anymore. The hardware its-self seems to work fine, I’ve verified it by flashing back to px4 pro.

So, does ardupilot not work on a pixhawk 1 or is there something I need to change in order to get it reading PPM signals?

If it matters, I flashed with QGroundControl to ardupilot chibios - multi-rotor - pixhawk1 - 4.0.3

Is it a 1Mb version Pixhawk? If so then you would want the Pixhawk1-1M firmware.

You’re right, I was using the wrong firmware. I’ve switched to the 1MB. However, the PPM input still doesn’t work.

This should be the same as PX4. What Rx are you using?

It’s an old tactic 6 channel TRX600 72Mhz. Leftover from an old RC plane I had in the garage. It’s connected via a PPM encoder that came with the Pixhawk kit. The PPM encoder is a board labeled YRRC featuring an atmel mega328P chip.

The Tx and Rx are rather old. If they didn’t work perfectly with the px4 firmware I’d assume straight away that they were trashed… but they do work with that firmware hence my head scratching.

Honestly, i don’t even want an RC to manually fly the drone but it appears to be a requirement as far as I can tell.

I plan to control it with the telemetry system / preprogrammed flights.

That is some old stuff! There is some info in the Wiki about that, or a similar PPM Encoder.
https://ardupilot.org/copter/docs/common-ppm-encoder.html

You can control an Ardupilot craft without an RC system but you would definitely want to get it flying and tuned with one before attempting that.