After my first post using a Bluetooth module, things have evolved a bit. The challenge with these Bluetooth modules is: they look the same, but having different firmware. I did not fully realize that until I have ordered another bluetooth module from dx.com:
DX.com Bluetooth Module (HC-06)
That module comes already on a carrier, so I assumed I can use the same driver as for my other module. I was wrong 
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For many projects, I have one common problem: I run out of I/O pins on my microcontroller . Luckily, I’m not alone, and the industry has created solutions for this kind of problems. One is to use a shift register as the 74HCT595/SN74HC595 which gives me 8 extra output pins. All what I need to spend are are 3 GPIO pins. Not a bad deal: I spend 3 pins and I get 8 (or multiple of it) on return 
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So why do I say this for this Arduino Motor/Stepper/Servo Shield tutorial? I have asked in this earlier post with a poll for the next topic (relais, motor or command line interface). Right now votes are mostly for relay. But before I can do relay (or DC motor), I need to first cover the 74HCT559. So here we go to have you ready for the next tutorial
Arduino Motor Shield with 74HC595
I’m working with a student on building a small autonomous robot platform, based on the FRDM-KL25Z board. We integrated new software modules, compiled and linked, and then downloaded the application to the board. While debugging and stepping through the application startup, I had this:
The Debugger has lost communication on connection
Outsch! That’s not good. Even worse, trying to connect again to the board failed . What happened?
The Pololu Zumo chassis is nearly perfect for my needs: it is small and compact, and neatly works with the FRDM-KL25Z board. I’m able to use it for line following or maze solving. But it lacks a position (quadrature) encoder on the wheels which is either very useful or even required for the lecture assignments for my next class. The Pololu Zumo chassis mainly has been designed for Robot-Sumo competitions, where such quadrature sensors are not really needed. Pololu offers optical quadrature sensors for their 42×19 mm wheel which I used in this project. So why not adding these sensors to the Zumo chassis?
FRDM-Robot with Quadrature Sensors Mounted
Having many projects open the same time, and working on them in parallel is a challenge. Ok, the human brain is not built for multitasking, but I still try 
. What I typically I end up in my Eclipse Problems View to have entries from multiple projects mixed up:
Problems View with Entries for multiple Projects
How to show it that I can fix the problems for ony project only, and not showing all problems from all projects?
I stumbled now twice over a problem, and only after a lot of head scratching (you should see my head now ) I have found the cause (and solution) for it. In the hope that I can save the readers of this blog some time, here is what happened.
I described in earlier posts how to enable GNU build tools to generate hex/bin/S19 files, or to write the code size to the console view. That works fine for me. But then I received a project were obviously this does not work: even with the project settings configured properly, there is no S19 file, and no code size printed. What’s wrong?
Additional Tools in ARM GNU Eclipse Panel
About a year ago I started to use the FRDM-KL25Z board (RevD). Finally, I had it in my hands: the RevE board from Mouser Using the RevD board, I faced several problems:
The good news: all of them have been improved in the FRDM-KL25Z RevE Schematics:
FRDM-KL25Z RevE Board
