PIC Microcontroller Series - 1

A Beginner-Friendly Introduction Using the PIC10F200

If you're curious about microcontrollers but don't know where to begin, the PIC10F200 is one of the simplest — and most charming — places to start. It's an 8-pin device with just enough features to teach the fundamentals without overwhelming you. Think of it as the "Hello, World" of the PIC ecosystem.

In this post we'll walk through:

What you need to start programming PIC microcontrollers
How to set up your development environment
A simple LED blink program in assembly and C
How each language affects program size on a tiny device like the PIC10F200

By the end, you'll have a working development setup and your first running program.

What you need to begin

PIC microcontrollers are extremely accessible, but you do need a few tools to get started.

1. A PIC microcontroller

We'll be using the PIC10F200, a baseline 8-bit PIC with:

256 words of program memory
16 bytes of RAM
4 GPIO pins
Internal oscillator
No peripherals (which is great for learning fundamentals)

2. A programmer

To load code onto the chip, you need a hardware programmer such as:

PICkit 4 or 5
MPLAB SNAP (budget option)

These connect to your computer via USB and to the PIC via the In-Circuit Serial Programming (ICSP) pins (VPP, VDD, GND, ICSPDAT, ICSPCLK).

3. MPLAB X IDE + XC compilers

Microchip's free development environment includes:

MPLAB X IDE — project management, editing, debugging
XC8 Compiler — for C programs
pic-as — Microchip's modern assembly toolchain

Once installed, you can write, compile, and program your PIC all from one place.

4. A simple test circuit

To verify your setup, you only need:

PIC10F200
One LED
One 220-1kΩ resistor
Breadboard + jumper wires
5V power supply (or USB power module)

Connect the LED to GP2 through the resistor, and you're ready to blink.

PIC10F200 pinout diagram

Once the chip has been programmed, you only need to supply power and a common ground. Then your electrical schematic would look like this:

Blink schematic

Your first program: "Hello, World" for microcontrollers

In embedded systems, the classic "Hello, World" is a blinking LED. If the LED blinks, you know:

Your programmer works
Your IDE is configured
Your PIC is alive
Your code compiled correctly
Your wiring is correct

It's the perfect sanity check before diving deeper.

Check out the GitHub links below to use my examples for assembly and C code. We'll cover what's actually going on in this code in future posts.

Assembly vs. C: program size comparison

One of the most interesting lessons on a tiny PIC like the 10F200 is how dramatically program size differs between languages.

Here's what beginners usually discover with this blink project:

Assembly — Extremely compact; you control every instruction.
C (XC8) — Easier to use with predefined functions like __delay_ms(). C typically reserves space for variables, stack, and runtime housekeeping (even if unused), which adds to the RAM usage.

The PIC10F200 has a limit of 256 words total. You can fill it surprisingly fast in C.

This doesn't mean C is "bad" — just that on baseline PICs, you must be mindful of memory. On larger PICs (PIC16F, PIC18F), C is the dominant choice. But on the 10F200, assembly is still very practical.

What beginners learn from this exercise

This first blink program teaches several foundational concepts:

✔ How to configure GPIO — TRIS registers, input/output modes, and the quirks of GP2 and GP3.
✔ How to use the OPTION register — prescalers, pull-ups, wake-up behavior.
✔ How to write and call delay loops — a classic embedded technique, especially on chips without timers.
✔ How reset vectors work — the PIC10F200's reset vector is at the end of memory, not the beginning.
✔ How assembly and C differ in size and structure — a valuable lesson for anyone working with resource-constrained devices.

Parts list

The PICkit programmer is the most expensive piece of this project, coming in at around $75. It's a one-time investment and it opens up a whole world of learning opportunities.

Here are the parts if you want to build this project yourself:

The MPLAB X Integrated Development Environment (IDE) is free from Microchip Technology. This application allows you to code, debug, and program (with the PICkit programmer) your microcontroller.

MPLAB® X IDE | Microchip Technology

Where we go next

Now that your toolchain is working and your PIC is blinking happily, the next steps could include:

Review the PIC10F200 datasheet
Understanding the PIC10F200 architecture
GPIO deep dive (latching, read-modify-write behavior)
Writing your own delay routines
Using the watchdog timer
Creating your first reusable library (in assembly or C)

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