It’s a way to “talk” with different devices.
I have a radar module.
It can “see” through walls, and detect even the slightest movement.
…and it has UART interface.
By sending commands on the UART interface, I can make the radar do what I want it to do.
When I just got the radar, I didn’t know how it worked.
The easiest way for me to figure it out was to connect it to my computer and send commands.
Just to see how it behaved.
To connect it to my computer, I needed a USB to UART converter.
But I didn’t have one.
Instead, I had an Arduino.
I connected the “reset” pin to ground with a jumper wire. This kind of disconnects the microcontroller from the rest of the board.
Which means that I could use the Arduino as a USB to UART converter by using the RX and TX pins (pins 0 and 1) on the board.
Keep on Soldering!
PS! You can find the 2nd edition of my eBook “Getting Started With Electronics” in the link below. Unfortunately, I forgot to smile in the video…