Published: 06 August 2021    Last Updated: 03 July 2023

UART stands for Universal Asynchronous Receiver/Transmitter, however in the context of Hardware Hacking we’re generally looking for an serial interface which will give us text output from the system and possibly allow for command input. The general intention from the manufacturers point of view – is to allow easy debugging, both out of the factor (to check the system is working as intended) and if a device is returned as broken.

As with JTAG, sometimes it’s conveniently highlighted on a target board for you, as with this example. The below photograph showing an exposed UART in yellow (and incidentally JTAG in red). Here it’s neatly placed to one side of the board to allow for easy access. That’s not necessarily the case, but either way you can find possible UART access with a JTAGulator, as I’ll show.