Introducing The Freedom Board
The Freedom Board KL25z is an inexpensive (about 12 AUD) Arduino form-factor compatible platform which sports a microcontroller with a 32-bit ARM Cortex M0+ core, rather than the humble 8-bit AVR CPU of the Arduino itself. The board includes an OpenSDA debugger/programmer so no other hardware is required, other than a USB cable.
At the time of writing, it appears that the Codewarrior for MCU 10.3 beta is no longer available. This is a shame as, using gcc for ARM, this beta (Windows only) gave unlimited code size. The regular Special Edition (free) only allows up to 64kb code size. This isn’t to say that other development environments can’t be used, as an ARM Cortex M0+ is an ARM Cortex M0+, whatever the manufacturer. However, I like to use this Eclipse-based IDE as it features the excellent Processor Expert, which allows rapid configuration and code generation for on-board peripherals and common tasks.
Another reason I like to use Codewarrior is that Erich Styger’s blog is an absolutely first class learning resource for both Codewarrior/Processor Expert and the Freedom Board itself. Combine this with the Freescale Community site, and you will be well-supported in your efforts to make your Freedom Board do Cool Stuff.
I – and others – have been through some very frustrating times with the Freedom Board due, in my mind, to poor documentation. It will not debug from Codewarrior out of the box. The supplied firmware allows for drag-and-drop programming. To go to more conventional debug/programme with Codewarrior, it is necessary to change the firmware to get the full benefit of the OpenSDA goodness. Erich Styger describes the necessary process here.
All in all, the Freedom Board KL25z is an excellent tool at an exceptional price – made all the more valuable when combined with Erich Styger’s learning resources.
For those interested, an alternative product from Texas Instruments exists in the Stellaris Lauchpad. This ARM Cortex M4F-based tool comes in at a similar price point. Rather than following Arduino form-factor, the Stellaris Launchpad follows on from TI’s previous MSP430 Launchpad, and is compatible with some of the Booster Packs (equivalent concept to the Arduino shield.)
Whether experimenter, student, or embedded professional wanting to do rapid prototyping, the Freedom Board and the Stellaris Launchpad have made working with ARM Cortex microcontrollers very simple and affordable.