The Raspberry Pi in an Analog World
In This Chapter
Discovering what analog means
Creating the Raspberry Ripple
Making a Steve Reich machine
Building a light-controlled instrument
Making a thermometer
In the previous two chapters, we showed how the Raspberry Pi could sense logic levels on the GPIO pins when they were configured to be inputs. We also showed how you could switch LEDs on and off when GPIO pins were configured to be outputs. We also showed how, by using a transistor, you can use the Pi to control much larger currents than you can get directly from the GPIO pins.
In this chapter, we show you how to use the GPIO to talk to other integrated circuits. There are many ways to do this, called protocols. This chapter concentrates on one called the I2C protocol. Many integrated circuits use this protocol to allow you to do many things. However, one very different sort of thing is how to input and output, not in the strict on/off way of the digital world you have ...