This chapter describes the interface between the digital and the real world. Most physical signals such as temperature, humidity, pressure, current, speed and acceleration are analogue signals. With the aid of the appropriate transducer, almost all of these can be represented as an electrical voltage between Vmin and Vmax, e.g. 0...3V, which is proportional to the original signal. The purpose of the ADC is to convert this analogue voltage to a digital number.
Most applications require not only one analogue input signal to be converted into a digital value, but their control loop usually needs several different sensor input signals. Therefore, the F2833x is equipped with 16 dedicated input pins to measure analogue voltages. In addition, the F2833x ADC has an auto-sequencer capability of 16 stages. This means that the ADC can automatically continue with the conversion of the next input channels after the previous channels are completed. Thanks to this enhancement, we do not have to fetch the digital results in the middle of a measurement sequence, the task being carried out by a single interrupt service routine at the end of the sequence.