After I completed the filament driver and the circuit to drive the multiplexed VFD segments, it is time to finish the VFD clock project I had in mind earlier.
On the circuit side, there isn’t too much to it. All I needed was a realtime clock and a microcontroller to interface with the RTC and the VFD driving circuit I discussed before. The RTC chip I used is a high accuracy DS3232 from Maxim. A more popular RTC chip such as DS1307 can also be used here without too much programming change. The microcontroller I used is an Arduino bootloaded ATmega328P. Since the VFD driver circuitry requires a higher DC voltage (e.g. 27V, a few milliamps) for the anode plates and gates but the TTL circuit only needs 5V, the power supply must be able to provide both required voltages.
Check out the video after the break.