Finally I have found some time over the past week-end to enhance my Zumo robot. After I had my line following robot based on the Pololu Zumo chassis and the FRDM-KL25Z, I thought it should be easy and logical to solve a maze. Logical: yes. Easy: not that much. In fact it took me longer than expected. As always, there are a lot of tiny and important problems to solve (the maze alone was easy 🙂 ).
Zumo in the maze
For many of my applications I’m using a PWM (Pulse Width Modulated) signal. One example is the motor driver used in this project where I use one PWM signal for each motor. Another usage of PWM is to control the brightness of an LED. Processor Expert makes usage of the PWM hardware easier. Still, for some settings it is good to have the resulting signals in mind. So in this post I’m showing how the settings impact the PWM signal generated.
I knew about mbed already for some time: watching students using it for an NXP enabled board. Pretty cool stuff: mbed is an online IDE and compiler with tons of software libraries for the supported platform. So I was dreaming to have something like this for my own boards like the Freedom board. But because mbed only supported two dedicated NXP boards, that was a road block.
But then mbed announced recently that the mbed SDK is open source. Wow, that is interesting! And finally the announcement last week: mbed supports the KL25Z Freedom Board. Now they have my attention :-).
Probably I need to add 3rd monitor to my laptop system, or maybe I’m not organized enough. But as a matter of fact: I want to have as many source files as possible open in Eclipse. But there is simply not enough screen real estate to show them all:
Many source files open
With that many source files open, I need an effective way to switch between the files.
There is now an example project available on GitHub which runs FreeRTOS on the FRDM-KL05Z board:
FRDM-KL25Z Board with FreeRTOS
Eclipse is a good IDE. At a first glance, it does the job. Good enough. At least for myself, I was not that much excited when I used it the first time. I came from the Microsoft Visual Studio world, and have used many other proprietary IDE’s. So Eclipse was just ‘yet another one’. But what Eclipse makes really great is the incredible wealth of functionality which is not visible right away. Yes, this is the same for any other software tool: it takes time to explore, and once you know things well, you do not want to switch or even consider something different. Same for me.
The other thing is: after some time, I get used to things, and I do not appreciate it that much any more. Only until someone reminds me that maybe things are not that well-known? This is what happened to me two days ago: I did some editing in Eclipse, while a colleague was watching me doing this. Then he said something like this
“Hey, what did you do? What was that?!? How did you do that?”
I do not remember his exact words, as I was surprised as well. I did not do anything special? Kinda standard Eclipse thing. Well, maybe not.
Because my first line following robot was this week at the Embedded World conference in Nürnberg, I have constructed another one around the Freedom FRDM-KL25Z board. It is based on Pololu part items and the Arduino motor shield, plus using a Bluetooth module I have used in an ealier post.
Pololu Line Following Robot with FRDM-KL25Z
Sometimes I’m looking for a functionality, and I cannot find it. But this does not mean that it does not exist ;-).
The Eclipse preference pages have a great filter text field: If I want to change a setting which has something to do with ‘color’, I can enter that text and it will show me all setting pages having something to do with ‘color’:
Eclipse Preference Filter
Sometimes things take longer than anticipated. And this is definitely the case for my USB MSD Host project where I wanted to use a USB memory stick with the Freedom FRDM-KL25Z board.
Memory Stick attached to the Freedom Board
But finally, I have things working. At least most of the time ….
The first FRDM-KL25Z Freedom Logic Analyzer firmware was missing one important feature: Triggers! But this weekend the firmware has evolved a bit :-).
Trigger Settings
MCU on Eclipse 