Today I attended the regional ‘Design with Freescale’ seminar. It had a part with a hands-on training using PEG for the Tower K60 + TWR-LCD board. It was the first time I had my hands on PEG which is a good learning experience. I learned that it is possible to fill more than 200 KByte of Flash with a simple LCD Touchscreen application which only has two screens, two buttons, a static text and two small bitmaps ;-).
In “Tutorial: Enlightning the Freedom KL25Z Board” I used the RGB LED on the FRDM-KL25Z board. This tutorial extends it to use the MMA8451Q inertial sensor on the board which is connected through I2C to the KL25Z processor:
Freedom Board Block Diagram with MMA8451Q (lower right corner)
The goal is show the accelerometer x, y and z-axis on the RGB LED.
P&E has released information and firmware instructions for using the OpenSDA, see pemicro.com/opensda. Future has posted a very useful article about using OpenSDA here. So time to upgrade OpenSDA bootloader and firmware v10.1. My FRDM-KL25Z board is a pre-production board, and I assume the production boards expected next week will have the new firmware on it. But it is always useful to know how to change/upgrade the firmware, as I expect there will be new versions of it in the future.
With my Freedom KL25Z board I’m using the GNU/gcc build tools and Eclipse/CodeWarrior. When I wanted to create an S19 file of my application using the GNU tools, this was not that easy to find out. So here are the steps to do this:
I open the project setting using the menu Project > Properties and go to C/C++ Build > Settings > Additional Tools and enable’Create Flash Image‘:
Additional Tools gcc Settings
The schematics for the Freedom board is now available on the element14 Freedom Board site (you need to log into the element14 community first) as FRDM-KL25Z Schematics (SPF-27556_D).pdf (314.7 K)). So time to write a tutorial how to use the LED on that board.
❗ Note: since this tutorial, the LED component has been simplified. So some of the steps below are much simpler and easer. Please see LED’s for Kinetis, simplified | MCU on Eclipse. I have updated this post with the new instructions and images.
In “FreeRTOS with GCC, Cortex-M0+ and Kinetis KL25Z Freedom Board” and “A Shell for the KL25Z Freedom Board” I have used that board with an RTOS: FreeRTOS. But it is really easy to use that board without an RTOS (‘bare metal’) too. In this tutorial I’m providing step by step instructions to use the RGB LED on the Freedom KL25Z board with Processor Expert and the open source LED component.
In the ‘Pre-LDD age’, setting up a periodic timer event with Processor was really easy. With the concept of LED’s (see “There is a Time and Date for both Worlds”) things are a bit different. But once things are clear, it is not that hard. So here I’m doing a very exciting thing: blinking an LED using a timer! 😎
So I’m going to have an LED blinking every second. I’m using the TWR-K60N512 with an ARM Cortex-M4 and the Eclipse based CodeWarrior for MCU10.2. But it is easy to adopt it to any other Kinetis board.
I’m a big fan of physical UART/RS-232 ports on boards. So I was somewhat disappointed not to see a serial 9pin connector on the Freedom KL25Z board. But it is perfectly understood that for this price costs are critical, and a serial header or connector is pushing the budget for that board very likely out of the water. Still, I want serial connectivity for my applications.
Freedom Board with RGB LED
An SD (Secure Digital) Card interface is kind of standard for many applications today: it provides a lot of memory at a reasonable cost. Still, I need a software stack for it, up to the level of a file system. So far I was really happy with using FatFs: an open source FAT file system provided by Elm-Chan. I’m using the FatFs Processor Expert component already in multiple designs. What was missing: a port to the Freescale Kinetis ARM Cortex-M4 family of processors.
Yesterday was my ‘lucky day’: My Kinetis-L Freedom board arrived :-). This board is really nice and features the KL25Z from the recently announced Kinetis L Family. And guess what is the first thing I want to flash on that processor? Yep: some FreeRTOS tasks. But to get there, a few important things have to be sorted out:
Exactly the thing I was looking for! A small and affordable 32bit board with easily accessible microcontroller signals. The Freescale Tower boards are great, but the PCI Express connectors are not that ideal. I love that normal Berg connectors 🙂
