The new PIC16F87x family are much more powerful than their '84 predecessors (as was outlined in the PIC16F87x Review, EPE Online, April 1999). They have, for example, up to eight channels of analog to digital conversion available; they can be used for serial communications input/output at controllable baud rates; they can write to and read from addressable serial data memories; apart from enlarged program memories, they also have increased on-chip EEPROM data memory capacity; their special register set is much larger; and they can operate at up to 20MHz.

It is some of these attributes that are put to use now in this Data Logger. This double article, represents not only a highly useful constructional project, but also a mini tutorial, with particular reference to the PIC16F877. The Tutorial is not full in-depth coverage but, if you already know about using other PICs, it will certainly get you started with using the new devices for yourself.

After reading both articles, you should have a pretty good idea about the following aspects of the PIC16F87x family:

• Using PORTA and PORTE for digital input/output or analog data input
• Analog-to-digital conversion (ADC)
• Storing and retrieving data bytes using the PIC's internal EEPROM memory
• Storing and retrieving data bytes using external serial memory chips
• Transmitting serial data bytes to the outside world at different baud rates (up to 9600 baud)
• Using a PC to input serial data from PIC16F87x devices via the COM ports
• Inputting formatted serial data from all PIC analog channels (up to eight) to Microsoft Excel for display and printout as text and graphs