So, the next thing to do is to get our hardware set up. We are going to make use of the same Adafruit ADXL345 accelerometer we used in our A Motion-Reactive LED Cap project; and to display the details of the steps taken so far, we will make use of the same Pimoroni Scroll pHAT HD that we used in the Scrolling LED Badge project. Both of these devices use the I2C protocol to communicate with our Pi Zero. The I2C protocol was designed to get around some of the problems with connecting multiple devices to an asynchronous serial port or an SPI port. I2C allows you to connect (over short distances) multiple devices through the same bus. Each device connected to the I2C bus must identify itself with a unique device ID.
Thankfully, our ADXL345 and Scroll pHAT HD are set to use different IDs already. This means we can connect them to the same I2C bus on our Pi Zero...