“Buttoning” up the prototype

UPDATE: There are some major errors in all 3 PCB designs that were found after testing so I would not use them. I removed the links to help remove temptation.

After getting the potentiometers to work as expected I was highly motivated to move forward on this project. The next thing to get working were the digital relays that would serve as the buttons.

The TLP222a-2 is a opto-isolated 2 switch normally open solid state relay. It is really easy to use, apply voltage in the correct direction to the pins that drive the LED and the MOSFET based switch closes simulating a button press. This took only a few minutes to hook up and write the software for. Connect a digital output pin to the anode of the LED and ground to the cathode and the software can close the relay by bringing the digital output pin high. I verified this using a multi-meter set to continuity check.

Next I took the time to solder up my DIN-6 breakout board designed several weeks ago and used the multi-meter in continuity mode to verify my understanding of which pins of the DIN-6 port mapped to which pins on the breadboard. Finally I hooked the coco ground to a 2nd ground bus on the breadboard, and coco +5v to a 2nd positive bus as these needed to be connected to the output sides of all 3 chips in the system. I think hooked the output of one of the potentiometer wipers to the pin for joystick X and the other wiper to pin Y. I hooked up each button pin to one side of the relay switch and ground to the other. This completed the connections to the coco connector. I used a simple din-6 to din-6 cable to connect the circuit to the coco and used the right joystick port.

On the coco itself I wrote a short program that read the right joystick x and y axis as well as check the status of the buttons in a loop and let that run. I started the software in the arduino that incremented the x and y axis to both extremes and turn the buttons on and off and checked to see it working on the coco. It was a success. I can now control the coco joystick via software.

Finally I designed some PCBs. First the pcb for the tested circuit was drawn up in Eagle. Next I created designs for an MCP4251 dual potentiometer and also for the MCP4922 DAC to test.

The next steps are to test out each of the PCBs when they arrive and then I’ll work on software to read the xbox controller. Things are starting to come together.

Links to PCB designs:

41010 Version, 4251 Version and 4922 Version