The FRDM-KL25Z Open Source Logic Analyzer based on SUMP presented here was already very useful with the added trigger support. But it was not capable to do a sampling rate above a few hundred kHz. That’s ok for slower probing, but not for anything with a higher speed. Using DMA (Direct Memory Access) instead of timer based sampling can remove that limitation :-).
FRDM-KL25Z used as Logic Analyzer on another FRDM-KL25Z board
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
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 ….
When I create a new project for the KL05Z with Processor Expert, then it shows up as 48 pin LQFP package in the project:
48pin LQFP Package in Components View
However, when I look at my board, it has a KL05Z32 in a LQFP package with 32 pins:
FRDM-KL05Z Board
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
After working on an ADC example, a DAC one was missing. Julio E. Fajardo is a reader of this blog, and he was so kind to send me an example project for the FRDM-KL25Z. The example is able to produce produce different waveforms with the DAC. The project has two examples which they are enabled/disabled in main(). One example waveform the sawtooth:
Sawtooth_FDRM_DAC
The challenge with small microcontroller like the ARM-Cortex-M0+ is that they have very limited debugging resources. As such, the number of hardware break points is very limited (see this post). For example for the KL25Z on the Freedom board, I only have 2 break points available if I want to do stepping:
No more hardware break points available
I’m using serial communication in different flavors for my project: with the shell, with OpenSDA USB CDC, to use printf(), and with the Bluetooth module. Processor Expert is a big helper, but as for any software, it is not bug free. And there is a problem with Processor Expert in CodeWarrior for MCU10.3 in respect with Baud settings for a serial interface.
Probing the Bluetooth Module Serial Connection
In “Using the Reset Button on the Freedom Board as User Button”, I had the problem to find out why a setting did not make it into my generated code. There is the fundamental question: “How does a setting impact my microcontroller register settings?”. There is an answer to that question: The Configuration Registers view:
Configuration Registers View
MCU on Eclipse 