There are several digital clocks with analog displays around. They are somewhat unique giving the feel of the retro. With proper enclosure such clock becomes great design element. Following project was inspired by Alan Parekh multimeter clock. Originally there were three analog multimeters used in voltage mode to display hours, minutes and seconds. In this project there are three analog voltmeters used with their faces printed to match time scale – one for hours, one for minutes and third for seconds.
The clock code runs on PIC16F628A but time is synchronized every 30 seconds to master clock. Analog displays are driven through transistors by generating PWM signals that are equivalent to DC voltage. This part is fairly easy to implement on microcontroller. The clock also has a Chime circuit based on ISD1730 that gives “tick tock” seconds sound.