In this chapter, we learned a little theory about the analog world. We saw analog pins available on BeagleBone. Then we wrote programs to measure temperature using temperature sensor TMP36. We also learned about LDR connections and wrote a program to measure light intensity. There is a big list of available analog sensors like accelerometers, sound sensors, gas detectors, piezoelectric pressure sensors, and so on. They can be interfaced with BeagleBone using circuits and programs we learned in this chapter. All you need to do is change the circuit/program according to the datasheet of that sensor. Now we know how to read from analog input devices. But we do not know how to write values on analog output devices. In the next chapter, we will learn a new concept called Pulse Width Modulation (PWM) and how it can be used to write on analog components/devices.