In a chemical instrumentation course, usually analog signal conditioning, data acquisition, and digital signal processing are taught. Analog boards for easy interconnection of operational amplifiers are now available that make an introduction to analog signal processing easier. The digitization process can be demonstrated with microcontrollers. The cost of microcontroller development boards has decreased, and now they represent a cost-efficient platform to clarify the process of data acquisition. In this paper, we show the construction of a pH meter, and, as the development progresses, the characteristics of operational amplifiers and microcontrollers are exposed in the hope of making the internal operation of modern instrumentation more transparent.