Single Board Computer Serial Console Usage

When you work with Single Board Computers (SBCs) such as the Raspberry Pi or the Orange Pi, you sometimes do not have the luxury of a full desktop or even an SSH connection to interact with your device.  That's when the serial port on the board becomes quite useful.

In order to use the serial port on these SBCs, you will need a USB to TTL converter cable such as this...

They can be found from several sources, and are relatively inexpensive.

One thing to be aware of is "counterfeit chip"  cables that have trouble using the latest drivers.  I'm not sure how to distinguish them when you buy them, but they exist,  One workaround, if you have trouble with drivers for your cable, is to look for older driver versions.

Anyway, these console cables will include 4 pin connectors... usually colored Red, Black, Green and White.  They are respectively positive voltage (3.3v), ground, RX and TX.  When used on an board that is already powered, the Red lead is usually not used.

Here is where you would plug the leads into a Raspberry Pi...

The cable will look like this...

Once you have connected the serial cable, you can use a terminal application on your computer to access a shell on the SBC.  On Windows, I use PuTTY to connect.  In order to do this, the first thing I have to do is determine the COM port that is being used by the console cable.  To do this I use the Device Manager in Windows.  Once I have the comm port to use, I start PuTTY and set it up like this..

Once you click open, you should be connected and communicating.  You may have to hit return to get a prompt.

If it does not seem to work, you can try swapping your White and Green connections... sometimes the normal convention is not followed.

Well that's it for this post.  Enjoy.