Let's see what parts I've used. I had to solder twenty individual BJT transistors. One for every single digit. It’s more work, it takes a bit more space, but it’s the only way to ensure 150V doesn’t end up frying the 'brain' of the watch. And to power it all, I’m using a tiny module—just 15 millimeters wide. It’s the high-voltage heart. To control the BJTs, since the ATMEGA chip doesn't have enough pins, I'm using 2 MUX drivers. For the time I'm suing a DS3231 RTC IC. It also has an MPU6050 IMU for hand movement detection and a TP4056 charger IC for the battery. The rest are resistors, capacitors, buzzer, cell battery, and some other small components.