The heart of the clock consists of an ESP-32-DevKitC module from Espressif. Time is synchronized via NTP over a WIFI connection with the internet. The settings of the clock can be altered via USB or via the WIFI network connection.
The VFD tubes are driven in a 2 x 3 multiplex mode using a Microchip HV518P high voltage shift register driver. A simple 7555 based step-up converter generates the 50 V anode voltage, while a Texas Instruments PTH08080W step down module supplies the 1.1 V filament voltage.
- 9V DC power supply, 3 W maximum power consumption
- 12 or 24 hour time format
- date format dd/mm/yyy, mm/dd/yyyy or yyyy/mm/dd
- temperature display in Celsius or Fahrenheit
- supports DS18B20, DS18S20, DS1822, LM75 and SE95 temperature sensors
- RGB tube backlighting with selectable color options
- different colon separator modes (flashing, AM/PM, ...)
- 1-wire and I2C interface
- sleep mode with adjustable night light option and wake-up via a push button
- fully designed for through hole components and modules
- command server for network configuration
- the clock firmware was written using the Arduino environment