While working on a project for the FRDM-K20D50M, I faced a problem: I was running out of SRAM for my application. The GNU linker reports: “section `.bss’ will not fit in region `m_data'”: š¦
bss will not fit in region m_data
But my device has 16 KByte of SRAM, and I knew I use much less than 10 KByte. So what is the problem? Continue reading
I miss my old DELL laptop. Ok, the new one I received from IT services is not bad. It is faster and has a better screen. But I’m not really happy with the new keyboard. With the previous keyboard I was able to do a ‘PrtnScrn’ with a single key press. With the new one I need to press Fn + PrntScrn. And this is impossible to do with one hand:
Impossible to reach Fn+Prnt Scrn with one hand!
Yes, I have two hands ;-). But many times I need to do ‘print screen’ while having my other hand on the mouse :-(.What else can I do?
ā This article has been written for the version 4 of ĀµVision. There is an update for version 5 of ĀµVision here: “Using Keil Ī¼Vision 5 with Processor Expert“
The good thing with using ARM microcontroller is: there are plenty of tool choices. Even myself, I’m using multiple different tool chains. And while I’m heavily using Eclipse, there are non-Eclipse tool chains which have their advantages too.
The cool thing with CodeWarrior is that beside of Eclipse based, it comes with Processor Expert integrated. And I’m using Processor Expert a lot in my projects. But using Processor Expert does not mean I’m limited to CodeWarrior or Eclipse. So I can use CodeRed or IAR as tool chain with it. And this post is about using Processor Expert with the ĀµVision tool chain from Keil/ARM.
Keil uVision Splash Screen
The Freescale Freedom boards like the FRDM-KL25Z feature an Arduino header so I can stack shields on it. Unfortunately, the Freedom board does not generate 5V if not connected to the USB cable. This makes it not possible to be used with many shields like the Adafruit Motor Shield: such shields expect that the Arduino board is providing 5V through the Arduino header (Pin 10 on J9 on the FRDM-KL25Z). So I had to do hardware changes to generate that 5V if I used my board disconnected from USB, e.g. running from batteries through V_IN (pin16 (P5-9V_IN) on the FRDM-KL25Z.
J22 with Capacitors on FRDM-KL25Z RevE
The good news is that the Rev.E of the Freedom FRDM-KL25Z board has now a header J22 to make things easier:
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 :-(.
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 š ) 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 š Using the RevD board, I faced several problems:
The good news: all of them have been improved š in theĀ FRDM-KL25Z RevE Schematics:
FRDM-KL25Z RevE Board
MCU on Eclipse 