IMG_0267

This is the CPU board with a 8-bit microcontroller PIC12F629, a 20MHz crystal and a bypass capacitor to reduce the noise. This little board goes into a 70-210mm f/2.8 lens and an identical one is made for a 28mm f/1.8 lens. There is an internal oscillator but can only run at 4 MHz which is too slow for this application.

Done