We will start by looking at how to identify the pins once we have located the UART pinouts on a device.

The four pins that we are trying to find are as follows:

• Tx
• Rx
• GND
• Vcc

For this, we will use a multimeter, which can measure both voltage and current, thus acting as both a voltmeter and ammeter, hence the name, multimeter.

The following is what a multimeter looks like. Connect the probes as shown in the following image: