Build your own serial cable

Have a COTRE radio, but your serial cable won’t program it? Well build a cable to set up that radio!

The COTRE radio seems to be a little picky when it comes to its serial cables and some of the standard PL2303 Baofeng cables just don’t cut it. The good news is that you can use the cable you already have and replace the USB to Serial electronics for just a couple of dollars. The resulting cable can be used for both the COTRE radio and Baofeng radios.

Previously, I went through the different cables I was able to buy off of Amazon and found that the CH340 and FTDI cables worked well. These are still around $10 each, but the CH340 USB-serial modules only cost about $1 each. The FTDI adapters also work fine, but the prices for the real ones are about $10 each. The plus side of those to me is that they have 1.8V serial which is useful for some microcontrollers.

/build-a-cable/wiring.png I cannibalized the PL2303 cable. Simply sliding a flat bladed screwdriver under the corner will pop the cover off. I cut the wires and then tested the pin out using the schematic above.

You can make one of these cables by following Miklor by desoldering the included pin header and then soldering the wires directly to the now open holes.

As an alternative, take a look at making your own crimped connectors. The 2.54mm “Dupont” connectors show up on many different devices and being able to crimp your own makes making connections easy. I bought mine to make modifications to my 3D printer. All you need is a crimper tool and a box of connectors.

blinky.jpg Works for with CHIRP on the Baofeng and works with the AUCTUS CPS.

  • Works
  • No more PL2303 driver issues
  • Cheap
  • Blinks
  • You can make it yourself.

Slightly uglier than your average store bought cable.

If you have the need, this project takes about 15 minutes to make