Since I got Home Assistant to control all my AV equipment, I’ve spent a long time trying to find a decent hardware remote I could use. I went through a bunch of options (buying a remote that really wanted to be like the Harmony, using a remote with a USB reciever, etc), but every time I just wanted to use the Harmony Companion Remote that came with my Harmony Hub, but without having to use the Hub (since it’s tied to the cloud for config and Logitech could turn that off anytime).
About a year ago someone if the forum pointed out this set of Arduino sketches that let you receive the radio signals from the Companion Remote.
The author did all the really hard work of decoding all the Companion Remote communications and the left it there for others to do something with it. Which I did. I added the ability to have it show up as a device in Home Assistant with a KeyPress sensor. I lived with that for awhile, but you had to use two sketches (one to get the remote address, one to actually run the remote after manually adding the remote address), and you had to modify the sketch to make any changes. This weekend, I finally did the rest of the work. There is now one sketch that starts the device in discovery mode, saves the remote address in flash, then reboots and just works. There are a bunch of configuration options to let you use different ESP32 boards (including ones with a RTL8201 LAN instead of WiFi), so you don’t have to futz with the sketch. Just a little config in arduino_secrets.h, compile, and load.
There is also a wiki with a full set of instructions to get the board and transceiver setup, get the software setup, explains all the configuration options, and includes a fair amount of information about how I setup the HA automations and scripts to be the brain of the remote. There are also a couple STLs for cases for an Adafruit Feather and a wESP32 PoE board.
So I thought I’d share.