ABSTRACT
This chapter focuses on the acquisition and generation of analog signals using external modules, peripheral devices, or the devices already integrated inside the microcontroller. It presents special emphasis on the basic criteria used for the design of the external modules. Analog signals are common in measurement and control systems as well as in communications involving human intervention, such as microphones, speakers, and cameras. Analog signals carry information in their amplitude or in their frequency or period, and it is necessary to digitize them first to process them with digital circuits. Most of the signals that need to be measured in a control system are nonelectrical signals. The majority of the signals to control, such as the temperature in a room and the position of the head in a printer, as well as the signals to communicate the results to the user, are also nonelectrical.
