[rgbphil] has done a great job detailing how he built his Microdot wristwatch.This project is a lot more approachable than the pong watch we saw last month. If you’ve made a few printed circuit boards, but haven’t yet tried working with surface mount component, this is a great way to give it a try.
The parts count is pretty low, a few switches, resistors, capacitors, LEDs, a watch crystal, and a PIC 16F88 microcontroller.[rgbphil] is using a charlieplex so that a separate shift register is not needed to drive all of the LEDs. He goes into detail about the process of laying out the circuit. Some of the problems he encounters include how to manage all of the charlieplex connections in a simple way, how to program the chip once it’s on the board, and how to layout the controls for the device.
The display looks great in the video we’ve embedded after the break. We’re going to add these components to our next parts order and make this project part of the plan for getting us through the long cold winter ahead.