The 16F877A is one of the most popular PIC microcontrollers and it’s easy to see why – it comes in a 40 pin DIP pinout and it has many internal peripherals.

The 40 pins make it easier to use the peripherals as the functions are spread out over the pins. This makes it easier to decide what external devices to attach without worrying too much if there enough pins to do the job.

One of the main advantages is that each pin is only shared between two or three functions so its easier to decide what the pin function (other devices have up to 5 functions for a pin).

Note: A disadvantage of the device is that it has no internal oscillator so you will need an external crystal of other clock source.