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 🙂
My wife tells me that I have too many boards on my desk. That is only *partially* correct: there are many, but not *too* many. But I’m working on too many tasks, but that’s a different aspect :-). I’m using more and more the Kinetis SDK V2.0, and as a result of this I have multiple SDKs installed on my machine. Because with the SDK V2.0 I get a download for each device/board installed (see “First NXP Kinetis SDK Release: SDK V2.0 with Online On-Demand Package Builder“). So my list of SDK folders is growing, as shown with the ‘New SDK 2.x’ wizard in Kinetis Design Studio:
Multiple Kinetis SDKs
The same time, the amount of free disk space is reducing. What if I could combine all these SDK’s?
I don’t know if it is the same for you. But for me, configuring the pins on these new ARM microcontroller is a challenge: Most pins can do multiple functions, such as be used as I²C, UART or GPIO pins.
Configuring the pins ‘by hand’ is difficult, error-prone and usually the first thing I need to do for a new project/device. NXP developed a new tool for this task and previewed it at FTF 2016. It is available now both as web (online) and desktop (locally installed) tool. At FTF it was possible to play with an engineering release: time to get my hands on the public release :-). And as more and more student projects will start using that tool for their boards, I better have a tutorial for it :-).
One goal of this blog is to inspire engineers, in one way or another. And when I get reports back that things were useful, I like to share it :-).
So here is something what a team of young undergraduates (Przemyslaw Brudny, Marek Ulita, Maciej Olejnik) did for theirs Master Thesis work at the Politechnika Wroclawska, Poland: a very cool flying machine controlled by two Kinetis K66, having many sensors (on own designed boards) with a custom debug/programmer board similar to the tinyK20, developed with the NXP Kinetis Design Studio:
“Learning-by-doing” is one of the core principles of my embedded systems and robotics course at the Lucerne University. For this the students apply what they learned using a robotics platform. In earlier semesters we did a Sumo battle at the end. This time the challenge was to build a remote controller plus to add the ability to explore and solve a line maze:
I’m using FreeRTOS in most of my applications. There were only a few exceptions where an RTOS has to be used in safety critical systems: there usually it is not permitted to use any dynamic memory allocation because this adds the risk that a memory allocation could fail at runtime because of memory fragmentation or memory leak. And FreeRTOS uses a dynamic memory (heap) for the task stacks and the RTOS resources including semaphore, mutex and queues.
This is now a thing of the past. This week a new FreeRTOS Version 9 was released which does not need any dynamic memory allocation anymore: it is possible now to build completely statically allocated systems with FreeRTOS :-).
Dynamic and Static Memory Allocation in FreeRTOS V9.0.0
The challenge with the selection of a microcontroller for a project is: which one has the required number of UART, I2C, SPI? Combine this with the desired package (48pins, 64pins? LQFN?), the needed FLASH and RAM size and then even the hundreds of available microcontroller shrink to a handful only. And many times I need to make compromises: such as I need two hardware I2C, but the microcontroller matching all my other needs has only one I2C hardware. So I might end up with bit-banging the slower I2C bus. Doable, but not ideal.
What is cool that some of the newer NXP Kinetis microcontroller come with an interesting hardware: FlexIO. A peripheral hardware which allows me to implement a custom protocol, including driving WS2812B (Adafruit NeoPixel) LEDs with a FRDM-KL43Z board:
I mentioned the hands-on sessions on FreeRTOS I do this week at NXP FTF Tech Forum in Austin in my previous post. What we are using in the session is an Eclipse plugin in Kinetis Design Studio showing all kinds of FreeRTOS information:
Time is passing fast, and many components have been updated to make the compatible with the NXP Kinetis SDK V2.0. As a highlight, besides of FreeRTOS the following components are now usable with the NXP Kinetis SDK: