His clever solution is to use an Arduino Uno R4 and take advantage of the onboard DAC. To turn on a segment, he connects a segment to a GPIO pin set high while sending 3.5 volts out of the DAC ...

This is the upgraded starter kits with power supply module, 9V battery with dc High quality kit with UNO board, compatible with Arduino UNO R3, UNO R4, MEGA 2560 R3, NANO.

There are also other Arduino boards capable of switching between different resolutions, such as the Uno R4 Minima that can ...