We've covered a lot of different types of device already—including input, output, and movement. This chapter delves into how these devices can be implemented in different ways and for different reasons. In this chapter, we'll take a look at the I2C and SPI protocols and their advantages and setbacks with Johnny-Five. We'll also take a look at how to add your own components to Johnny-Five, which gives us a good look into how these devices work and how you can contribute to the development of Johnny-Five! In this chapter, we will cover the following topics:
- Why do we need the I2C and SPI protocols?
- The SPI devices
- The I2C devices
- External devices
You'll need your microcontroller, a USB cable, and computer. You'll also need an ADXL345I2C Accelerometer such as the Adafruit Industries product ID 1231 or the SparkFun product ID SEN-09836, and an LED matrix kit from SparkFun—product number DEV-11861. You'll also need your LCD display from Chapter 4, Using Specialized Output Devices. Finally, you'll need a USB gamepad—I recommend the N64RetroLink controller that is available for about $15 on Amazon, but if you have a spare PS3DualShock 3 controller, I will also include instructions for that.