DIY IO Simulator (AI, AO, DO)

I needed to create an IO simulator for testing a PLC (Programmable Logic Controller). I pieced together a useful tool to do the trick of simulating analog and digital input and output that was expected from sensors in the real world.

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This simulator can be used with any electronic device that used Analog In/Out or Discrete in/outs.


For instance this simulator could be used for testing with an Arduino, Netduino, PIC, PLC, or RTU.

Analog and discrete values are universal in the world of automation. An example of a discrete is a switch that is on or off, analog values have a range of values like the volume knob on a radio.

The enclosure I used was from an old bad RF modem (radio) that I had lying around.

The LCD screen is a ST7565 picked up from Adafruit and powered with an Arduino. I have a post detailing the ST7565 and Arduino Sketch available for download.