If you are looking for a cheaper solution than the $35 Raspberry Pi to run pEye Witness Protection, look no further than the Orange Pi One than can be acquired for less than $20.
I must warn you that the Orange Pi setup is not as clean or easy as it is on the Raspberry Pi and unless the extra $15 is make or break for you, or you enjoy a challenge I highly recommend going with the Raspberry Pi.
The Orange Pi One is what I used, but I'm sure other models could be used as well. The Orange Pi One can run many OS images but I ended up using Ubuntu. OS images can be downloaded HERE.
I did try Raspian and Debian before Ubuntu, but both gave challenges that I assume could can be overcome with a little work. Ultimately I found out that both Chromium and Firefox browsers are troublesome on any of the images I tried.
The other thing I should point out is that the Ubuntu image for the Orange Pi One comes with Chinese as the default language. There is a YouTube video that walks through the simple steps to set it to English.
Other than that, and the Orange Pi One lags a bit, the installation of pEye Witness Protection was identical to installing on the Raspberry Pi. Also note that the Orange Pi One only has 1 USB port.
🎯pEye Witness Protection (pWP)
pWP simply stores the brainkey pub_key of your 2 nodes (active and backup) and monitors your witness missed blocks reported by the chain. When a new missed block is reported, the pWP will send the witness update command to the chain and set the backup public key as active. That way next time your witness gets into the block rotation, it will be your newly defined active node that will produce the block. It will also send an email notifying you of the issues in real time.Discord.