The GoodWatch21 is the second model with a functional radio, tuned to 433MHz (70cm). Its firmware is stable and ready for daily wear, with years of battery life when the radio is off.

All parts are assembled as described in the schematic, except the chip antenna, which cannot fit between the PCB and the LCD. We are currently experimenting with using the watchband as a random wire antenna by running a wire-wrap wire around the PCB and out through the watch case.

See the BootStrapLoader page for flashing and testing instructions.

Schematics are available as goodwatch21.pdf. A BOM, Kicad files, and Gerbers are available within the Git repository.