As a standard procedure, I add some console functionality to my embedded applications. That way I have a command line interface and can inspect and influence the target system. One interesting hardware feature of ARM Cortex-M is Single Wire Output (SWO): it allows to send out data (e.g. strings) over up to 32 different stimulus ports, over a single wire.
From time to time I face some problems which are really hard to find. Mostly these kind of bugs are very timing sensitive and depend on interrupt execution order. Maybe a dangling pointer is overwriting memory, code is running wild, or some functions are not reentrant as they should be. For these kind of bugs, good tools are worth their weight in gold. The Percepio FreeRTOS+Trace and the Segger SystemView have helped me many times to narrow down such kind problems in my applications. Another ultimate tools is hardware trace: Now I have a Segger J-Trace Pro for ARM Cortex-M in my arsenal of bug extinguishing weapons on my desk:
Dear bugs, look what I have on my desk. Your hiding time is over!🙂
Playing with RFID and NFC is definitely fun🙂, and they are everywhere! For a research project I’m exploring different RFID tags and solutions. I several types around for a long time, but never found the time to actually work on it, so last nightI thought I give it a try, and I have it working with GNU ARM and Eclipse, powered by the NXP FRDM-K64F board🙂
I kind of hoped that after “Why I don’t like printf()” and all my other articles about printf and semihosting, that topic would be 200% handled and I won’t have to deal with any more. Well, I was wrong and underestimated how the Kinetis SDK is interfering with semihosting. And I underestimated how many of my readers are still using semihosting (even as there are other and better alternatives), so I keep getting questions and requests for help. That’s ok, and I hope I can help🙂.
So here is yet again another post about how to turn on semihosting with Eclipse, GNU ARM Embedded and the Kinetis SDK v2.0. This time with the FRDM-K64F board:
I’m using the Segger SystemView in many of my applications to get insights of the running application. A reader of my blog pointed me to the company ‘toem’ (http://toem.de/) based in Germany which offers powerful data viewer (‘impulse’) for Eclipse. I have tried this out, and it is really an amazing piece of technology with lots of potential. It allows me to view Segger SystemView data🙂
Smartwatches are around for a while now. To me it is still questionable how useful the ‘big’ ones for iOS and Android are. But there are definitely the crowd funded smartwatch projects which caught my attention. Maybe it is about the ‘do-anything’ with connectivity? One of these gadgets is Hexiwear: a hackable open source device
While it *could* be a kind of smartwatch, the value of this thing is more that it includes a plethora of sensors with two microcontroller, and I can use Eclipse with GNU tools to build my firmware🙂.
Alert: Hackster.io is giving away 100 Hexiwears, but you need to hurry up (submission until July 15th 2016)!
Sometimes things don’t go well, especially with bringing up a new board design. I always sweat blood that first minute when I try to connect with the debugger to a new design: Will it work? After the optical inspection, performing electrical tests (no shortcuts? voltage levels ok?) the inflection point is when I’m connecting the first time with the debugger to the new board: either it will properly connect and program the device (hurrah!) or it will fail and potentially difficult hours of investigations have to follow.
More and more of my students are using Microsoft Windows 10 machines, and my computer has been upgraded to Windows 10 a couple of week ago too. From my work and experience, a new operating system causes always some challenges, and Windows 10 is no difference. And no, this is not about Microsoft vs. Apple vs. Linux, this post is about addressing a potential and painful problem which I have observed with Windows 10 machines, and to my understanding it could happen with any other operating system too. The problem is that somehow on several student machines the bootloader and OpenSDA application on their FRDM boards did not work any more.
FRDM-K64F (top) programming the OpenSDA Bootloader (bottom)
One of the major benefits of Processor Expert is that I can easily switch the device or processor used in a project. For example I can do my concept with a larger device with more FLASH and RAM, and then at the end easily switch to a smaller or even completely different device very quickly. For example I have a project working with the 64KByte FLASH version of the KE02Z (KE02Z68VLH2):
For a university research project I need a fast microcontroller with lots of RAM and FLASH memory. I have ordered a TWR-KV58F220M board from NXP which arrived yesterday. The special thing is that it has on of these new ARM Cortex-M7F on it:
A bootloader shall be small and concise. I very much like bootloaders which do not need a ‘special’ program on the host, so I prefer a simple terminal for this. While porting my serial bootloader to the NXP FRDM-K64F board, I have found RealTerm which offers a lot of cool features:
3.5″ Diskette Drives are not widely used any more: CDs, DVDs, memory/thumb drives and downloads from the web are the usual distribution method these days for software. Back a few years ago, software was distributed on one or many 3.5″ diskettes, and even before that time on 5 1/4″ floppy disk drives. So what to do with all these not-used-anymore hardware? Play music with it🙂