This chapter described the principles of operation and use of an analog-to-digital converter. The more popular types of analog-to-digital converters and their various methods of conversion have been explained. This was followed by a discussion of the importance of a sample and hold circuit and the effects of aliasing that occurs when signals are sampled too slowly.
We used our now familiar object-oriented approach to develop software for interfacing the parallel port of the PC with the ADC. We developed a new object class named ADC using an approach consistent with that of Chapter 10 when the VCO class was developed. This object-oriented approach has allowed us to develop the voltage and temperature measuring programs that used the ADC by making minor changes to the programs written for the VCO.