Hardware: RJ45 to GPIO adapter

So since the wire coming out of my controller is a Cat5 cable with an RJ45 connector, I made an RJ45 – GPIO adapter. It was easier than I had expected. When I went looking for a female-female RJ45 connector (could barely believe I didn’t have one sitting around the house), I first went to the local dollar store and was disappointed that they were out of stock (go figure).  So I went to Home Depot and picked one up for $3 (the one at the dollar store is $1).  I’ve looked around for more since then (just for curiousity’s sake) and they go for $8 at Radio Shack. I’m pretty sure they’re not all made the same though. I lucked out on the one I got as it was super simple to modify. I just twisted it open and the two sides are connected nicely by 8 wires.


These wires are connected to thin pins which feed through the case and touch the Cat5 wires. I just unbent the pins and pulled them out so that the wires were easier to work with. I then soldered the Cat5 wires to the RJ45 connector wires.


After that it was just as simple as pushing the thin pins back into the connector and bending them into place. WAY easier than I had expected.


There it is. A very clean and neat connector that makes hooking up the controller and disconnecting it for storage VERY easy…not done though. At this point, I had to figure out which wires went where on the controller so I got out a volt meter and just tested each one. I then used the chart on this page to hook the connectors into their respective spots on the RPi and gave it a whirl. My main problem at this point was that I had installed the joystick vertically instead of horizontally and my joystick controls were 90 degrees off. I just moved the GPIO wires around until I got it correct.

At this point everything works fine with the exception of the 3rd button I installed. The software from Adafruit’s tutorial called for a 2-button controller so I have to manually map that 3rd button in order to be able to use it.

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