While browsing eBay looking at electronics stuff I found a few interesting items to connect to the Pi. The first item was a small 2-axis analogue joystick. They are similar to the thumb-sticks you would find on a modern games console controller. These modules are cheap and easy to connect to a circuit so I decided to get one. The outputs are analogue so you need a mechanism for the Pi to read these voltages.
In this post I’ll show how you can you use this device with the Pi. Once working this could be used as an input device for all sorts of projects. Perhaps a Python game written using the Pygame module?
The device I bought was labelled “Keyes_SJoyes”. It consists of two potentiometers which give an analogue voltage based on the horizontal and vertical position of the thumb-stick. Pressing the stick activates a small switch. There are no fancy components on the board and because it is really just two variable resistors works fine with 3.3V despite the 5V PCB label.
In order to measure the X and Y voltages I decided to use an MCP3008 10 bit Analogue to Digital Converter. These devices are cheap, easy to setup and allow 8 analogue inputs to be read by the Pi using it’s SPI interface. In this tutorial we will only need three of its inputs.
See my previous MCP3008 post for details of how I used one to read light levels and temperature.
Read more here!