PIC microcontroller programming

PIC microcontrollers are a family of small, self-contained computers on a single chip, widely used by hobbyists and in embedded products. Programming a PIC means writing the software that runs on the chip and then transferring that program into its non-volatile memory. The work divides into two parts: developing the code on a desktop computer, and physically loading the resulting machine code onto the device using a hardware programmer. Free software tools exist for both stages, which has helped make PICs popular for learning embedded electronics.

Code can be written at different levels. Assembly language gives direct control over the chip's instructions and registers, while high-level languages such as C are easier to read and maintain. A compiler or assembler translates the source code into the binary instructions the particular PIC understands, since different members of the family vary in memory, peripherals and instruction set. The output is typically a HEX file describing exactly what to write to program memory.

That file is then sent to the chip by a programmer, a circuit that connects between the computer and the PIC and writes the data into its flash or EEPROM memory. Many PICs support in-circuit serial programming, allowing them to be programmed without removal from the board. PIC microcontrollers are part of a wider world of small controllers that also includes devices like the 8051 family and platforms such as the BASIC Stamp, each with its own tools and development style.

Frequently asked questions

What languages can be used to program a PIC?

PICs can be programmed in assembly language for direct control of the hardware, or in higher-level languages such as C, which are then compiled into the chip's machine code.

What is a PIC programmer?

A programmer is the hardware that connects a computer to the PIC and writes the compiled program into the chip's memory. Many PICs also support in-circuit programming without removal from the board.

What is a HEX file?

A HEX file is the output of the assembler or compiler. It describes the exact binary data to be written into the microcontroller's program memory.