Hachidori which means 'humming bird' is a remote sensor/actuator board controlled by ArduPilot running on PC. It's intended to contribute to ArduPilot, though it's still in the experimental phase. It's a tiny open project of DCoJA and the related programs and resources of hachidori are available there.
From hachidori point of view, ArduPilot looks like a UDP server which receives sensor data and sends PWM values back. It's a classical idea, but, yes, there are many issues with this scheme. See the article for some detail, though they would be obvious for experts. Anyways, here is a flight test of hachidori with a toy drone frame:
This frame is controlled by ESP32 and APM runs on a laptop PC with Ubuntu 4.4.0-lowlatency kernel. Looks APM can control the attitude well. For ArduPilot with the experimental hachidori drivers and ESP32 resources for the frame, the above my article gives the links to them. Almost of them are in DCoJA's github or my github.
I'm happy if you have some interests in this a bit crazy and classical idea.