I like astronomy and recently bought a telescope.
To start observing the sky, I found that would have the need for a level compass and a tilt meter to correctly position my telescope.
I could do all this calibration with my cell phone.
However, I thought that eventually I wouldn't be able to count on him, so I had the idea of assembling a device that would meet all my needs without a cell phone.
I used the following components:
Arduino Nano R3, LSM303D - compass - discontinued, lcd 16x2 - generic, I2C Serial Module for LCD Display - generic, push button - generic, on-off button with lock.
To make the software, I set up a sketch on the Arduino API with the help of some youtubers programmers.