https://ripnet.us My page about stuff Fri May 8 14:12:29 2026 / +0000 GMT Universal Post Manager 1.1.2 [ www.ProfProjects.com ] http://ripnet.us/?p=166 Fri May 8 14:12:29 2026 / +0000 GMT http://ripnet.us/?p=166 interface in the basement over an I2C bus (yes I know it's not the best choice for the distance, but it should work just fine). The ATMega328 has I2C hardware resources built-in on ports 27 (SDA) and 28 (SCL). For programming, I opted to use an FTDI serial programming interface and not include an ICSP header. I'll install a bootloader on the chip and just use serial to re-program it. This also gives me the ability to use the serial output for debugging. While working on the schematic, I noticed that I had just enough ports for 2 more encoders. I don't think I'll end up using them, but I included them just incase. Okay, the schematic is done! Let's turn this into a printed circuit board (PCB). I need this to fit inside an outlet box. I measured mine at 3" x 1.5" for a not-too-snug fit. I'll skip the boring details, but here's what I came up with:   Next I sent this design to OSHPark for manufacture. Stay tuned!]]> 166 2015-04-25 11:26:57 2015-04-25 15:26:57