It’s hard to resist the bargain bin – found an alarm clock module.
Now it has extensions for alarm control plus a radio power supply and FM stereo converter. Still in use today!
I designed and built an archery sight for blind people – electronics worked, but the optics failed 🙁
I really wished I could use an FPGA for this project, but the cost was in the thousands of dollars! I should have used a PIC – but the idea never entered my mind – that was a “computer” – not a logic controller! In the end I moved all my logic into an EPROM.
I bravely promised a friend it would be much cheaper and better to build a kit metal detector for some serious detecting. I tried two different kits – both were total failures with my build – sorry Dave 🙁