Chapter 6. Input and output
Often, an IoT device is accommodated in a small housing, in which there is no room for a full-size keyboard or a large display, and so it relies on a different form of input and output. For instance, the input device can be a set of buttons or a joystick, while the output can be a small LED display or touchscreen.
Such a device is the Sense HAT add-on board for the RPi2, which is equipped with an 8x8 array of RGB LEDs and a five-button joystick. (See Figure 6-1.) This joystick can control an IoT device, while the LED array can act as a simplified, low-resolution display.