ARM Cortex-M, Interrupts and FreeRTOS: Part 1

The ARM Cortex-M microcontroller are very popular. And it has a very flexible and powerful nested vectored interrupt controller (NVIC) on it. But for many, including myself, the Cortex-M interrupt system can be leading to many bugs and lots of frustration :-(.

NXP KV58F ARM Cortex-M7

ARM Cortex-M7: NXP KV58

Understanding the NVIC and the ARM Cortex-M interrupt system is essential for every embedded application, but even for if using an realtime operating system: if you mess up with interrupts, very bad things will happen….

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impulse: Segger SystemView in Eclipse

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 🙂

Segger SystemView Data in Eclipse

Segger SystemView Data in Eclipse

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NXP Pins Tool: Understanding Data for Offline Usage

I’m using the NXP Pins tool (see “Tutorial: Muxing with the New NXP Pins Tool“) now in several projects, and I think it is time to share a few tips and tricks.

Pins Tool

Pins Tool

So join me on a journey through the internals of the NXP Pins tool :-).

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Hexiwear: Teardown of the Hackable ‘Do-Anything’ Device

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

Hexiwear Device

Hexiwear 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)!

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Swiss Army Knife of Terminal Program for Serial Bootloaders

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:

RealTerm

RealTerm

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Tutorial: Making Music with Floppy Disk Drives

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 🙂

Floppy Music

Floppy Music

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Combining Multiple NXP Kinetis SDKs into One

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

Multiple Kinetis SDKs

The same time, the amount of free disk space is reducing. What if I could combine all these SDK’s?

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Constructing Software for Hardware

While developing a data logger for an advanced UAV inertial sensor I had to think about the quote below several times:

“There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult. It demands the same skill, devotion, insight, and even inspiration as the discovery of the simple physical laws which underlie the complex phenomena of nature.”
C. A. R. Hoare

Still my design is not simple, and still I have to discover the not so simple physical laws of that sensor :-(.

Inertial Sensor Setup

Inertial Sensor Setup

That quote from Sir Charles Antony Richard Hoare is so true. In case you did not know: he is the one who developed the quicksort algorithm. With this and all his other work he shaped the software and computer industry. And reminds me about the challenges and difficulties of constructing software……

Happy Constructing 🙂

Tutorial: Muxing with the New NXP Pins Tool

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 :-).

Desktop Version of Pins Tool

Desktop Version of Pins Tool

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