SparkFun Serial Basic CH340C Hookup Guide
Elias The Sparkiest 
Hardware Test
To connect the board to a computer, you will need a USB-C cable. Plug the USB-C cable into a USB port on your computer and the other end into the Serial Basic. Your computer should automatically install the necessary drivers and create a COM port on your computer. If you are prompted for drivers, please see the Drivers section.
The quickest and easiest way to make sure everything is working is to do a TX/RX loop-back. To do this, insert a jumper wire between TX and RX as shown below. Anything that is transmitted from the TX pin will be echoed back to the RX pin.
Now that you've got that plugged in, open your favorite terminal program. Select the COM port that the Serial Basic is assigned to, and connect. When you type a character, you should see each character you type echoed back in the terminal and the RX and TX LEDs will flash as you type.
