ABSTRACT
This chapter discusses the use of realtime clocks in PIC circuits and explores analog-to-digital (A/D) conversions in PIC software and hardware. In electronics, the typical A/D or ADC converter is a device that takes a voltage input and returns a binary digital number. Several popular integrated circuits are used to perform as A/D converters, among them the ADC0831, the LTC1298, and the MAX 190 and MAX 191. One of the advantages of using onboard A/D converters is saving interface lines. The PICs of the 16F87x family are equipped with an analog-to-digital converter module. The number of lines depends on the specific version of the device: 28-pin devices have five A/D lines and all others have eight lines. The A/D module has high- and low-voltage reference inputs that are selected by software. The A/D module can be made to operate in SLEEP mode.
