Don says the altimeter that the A-4 training came with was not the right one. For learning purposes, I'm creating a new altimeter to resemble it, with digital components.

Having recently started designing with 3D printing, I plan to replace the altitude digit windows with a single OLED display, the barometer with a 128×32 OLED display, the pointer hand with a stepper motor, and the barometer adjust with a rotary encoder.

I'm trying to see if a single Arduino Nano can handle all of this. The concern is that the Rotary Encoder and the Stepper Motor might both need interrupts.

This is an implementation which works with the 2 OLED displays, and a Rotary Encoder. I had to add software to establish a second I2C system to communicate with the OLED displays, because the first I2C system connects with the driver Raspberry Pi.