If you need help with any of this I can be found on IRC at ##tech40+ (irc.freenode). I’m in Australia, and usually asleep midnight till dawn EST (Australia).

What is Mecrisp-Stellaris ?

  • Released under Version 3 of the GPL, Mecrisp-Stellaris Forth by Matthias Koch is Free Software. See: https://sourceforge.net/projects/mecrisp/files/ to download your version
  • Mecrisp-Stellaris Forth runs on M0, M3, M4 and M7 ARM Cortex M chips. This is a big family of microcontrollers with a common processor architecture and very different peripheral capabilities.
  • The Mecrisp-Stellaris Distribution tarball comes with ready to run binaries for all supported chips, you don’t need to compile anything.
  • Despite the name, not only Stellaris chips are supported.
  • Mecrisp-Stellaris Forth fits into 19 kb of flash and runs with at least 1 kb of ram.
  • If you wish Mecrisp-Stellaris Forth ran on your favourite chip, just get in contact with Matthias, and maybe there will be another port soon.

What is Forth ?

If you are familiar with Forth already, then bypass this note and go straight to “Quick Start Here” below.


  • Forth was invented by Charles Moore
  • Forth is a program that once flashed into your MCU allows you to immediately write and test programs, read Registers, toggle GPIO pins, read the A-D and much, much more. No compiler is needed as it is built into the program, which is flashed onto the MCU. All you need is a serial terminal to talk to the MCU in Forth.
  • Mecrisp-Stellaris Forth can run on a single $0.60 STM32F051 MCU with zero external components, but you may need a filter capacitor depending on your wiring layout.

This is a STM32F051-QFN MCU I hand soldered onto 0.1” pitch fibreglass matrix board and flashed with Mecrisp-Stellaris. It has only one filter cap and works perfectly. Those large shiny wires are 0.5m wirewrap wire, exactly the width of the QFN pads.


Quick Start Here

This describes the basic steps to quickly install flash Mecrisp-Stellaris using your choice of methods.

Where to go now ?

Have a look in the Dictionary for all the commands you can use ?

How about running some ‘blinky’ programs on a F0 Discovery Board ?

STM32F051 Discovery Board, about $10


Where to go next ?

It’s traditional to build a LED ‘blinky’ as your first embedded program, and we have lots here, check out the Blinky Bazar

How about some working projects ?

You may be wondering, ‘if a chip has a thousand register and register bitfields, how will I ever write all those Memory Mapped words?’ Fortunately you don’t have to if you use svd2forth. So why not check it out ?

Into Object Oriented Programming ? we have some exiting new developments here

Any other tips ?

Sure, have a browse around this site (if you haven’t already):-

I’ve found some bugs, horrible spelling errors, or have some good tips, corrections etc, who do I contact ?