Some years ago a have started building Clone PI AVR. Made a PCB, soldered all the components and … and never found time to finish it until today. Well I haven’t finished it yet but at lest gave it a first test run. For the screen and buttons i have re-purposed some front panel of some old router. Now i see that i will have to put it in to another box for better mounting on the metal detector itself but this time it was good enough for test run. For Atmega programming I used Mini Pro TL866 programmer I have bought while ago – works like a charm. You can see some photos and video on work in progress.
I was annoyed with Eachines H8 Mine constant beeping in headless mode so decided to make it silent once and for all. This mod is easy – just open the transmitter, remove beeper by desoldering it and solder similar LED instead of it ( check the polarity – positive is marked on the PCB ). Then drill a hole of LED diameter in front side of controller case and it is done.