Using FreeRTOS with newlib and newlib-nano

For reliable applications, I avoid using functions of the standard libraries. They are banned for most safety related applications anyway. I do not use or avoid malloc(), printf() and all the other variants, for many reasons including the ones listed in “Why I don’t like printf()“. Instead, I’m using smaller variants (see “XFormat“). Or I’m using only the thread-safe FreeRTOS heap memory allocation which exist for many good reasons.

Things get problematic if malloc() still is pulled in, either because it is used by a middleware (e.g. TCP/IP stack) or if using C++. Dave Nadler posted a detailed article (http://www.nadler.com/embedded/newlibAndFreeRTOS.html) about how to use newlib and newlib-nano with FreeRTOS.

FreeRTOS Newlib Memory Allocation Scheme

FreeRTOS Newlib Memory Allocation Scheme

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DIY USB HID Joystick Device and Game Controller

For many projects it would be cool to build a custom USB Joystick device, either as custom game controller for Windows or any USB host which can be used with a USB Joystick. Instead buying one, why not build my version? All what I need is a USB capable board, some kind of input (potentiometer, push buttons) and some software, and I have my USB Joystick:

DIY USB HID Joystick Device

DIY USB HID Joystick Device

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McuOnEclipse Components: 06-May-2017 Release

I’m pleased to announce that a new release of the McuOnEclipse components is available in SourceForge, with the following changes and updates:

  • SEGGER SystemView updated to V2.42
  • More components to work with MCUXpresso SDK: GenericSWSPI, FXO8500 and SimpleEvents
  • SSD1351 display driver supports 128×128 pixel resolution and Adafruit 1.5″ breakout module
  • Extended FreeRTOS debug helper settings
  • GenericI2C: added ReadWordAddress8() and ReadWordAddress8() functions
  • RingBuffer with new Getn() and Update() functions
  • Utility with map(), constrain(), random() and randomSetSeed()
  • XFormat: new xsnprintf(), contributed by Engin Lee
  • OneWire protocol component with Maxim DS18B20 temperature sensor
  • Many smaller bug fixes and enhancements
SourceForge

SourceForge

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Is Developing for ARM more difficult than for other Architectures?

I believe in ‘life-long-learning’. With this I continue to learn and discover new things every day. I’m writing tutorials to give something back to the community from which I have learned so much.

On top of this, I receive emails on a nearly daily basis, asking for help. Many articles have the origin in such requests or questions. I prefer questions or comments in a public forum, because that way I feel all others can benefit from it. Last week Alessandro contacted me with this:

“Hi Erich,

I hope this find you well! I’m starting to using ARM processors, but I find them quite complicated on the configuration side. I started in the past with PIC micro (PIC16) with asm, and I found them quite straightforward to be configured (clock, IO, peripherals, …). Then I moved myself on C language, and on PIC18 without any big issues.

Now I would really like join the ARM community, I see that these processors are what I’ve always looking for, on energy, calc power, peripherals, and FINALLY on IDE (editor, toolchain and utilities)… AMAZING!!!”

The topic is about how to start learning developing for ARM. Alessandro agreed to make this public, so I thought this might be a good topic for an article?

Firmware

Firmware

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Tutorial: Secure TLS Communication with MQTT using mbedTLS on top of lwip

One of the most important aspects of the ‘IoT’ world is having a secure communication. Running MQTT on lwip (see “MQTT with lwip and NXP FRDM-K64F Board“) is no exception. Despite of the popularity of MQTT and lwip, I have not been able to find an example using a secure TLS connection over raw/native lwip TCP :-(. Could it be that such an example exists, and I have not found it? Or that someone implemented it, but has not published it? Only what I have found on the internet are many others asking for the same kind of thing “running MQTT on lwip with TLS”, but there was no answer? So I have to answer my question, which seems to be a good thing anyway: I can learn new things the hard way :-).

Blockdiagram MQTT Application with TLS using lwip

Block diagram MQTT Application with TLS using lwip

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MCUXpresso IDE: Installing Processor Expert into Eclipse Neon

In “MCUXpresso IDE: Importing Kinetis Design Studio Projects” I explained how Kinetis Design Studio projects can be imported and used inside the MCUXpresso IDE. Processor Expert projects can be used, but no new components added, modified or new Processor Expert projects created. To fully use Processor Expert, two plugins need to installed, and this is what this article is about.

Processor Expert in MCUXpresso IDE

Processor Expert in MCUXpresso IDE

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The Influence of Software and Tools on ARM Cortex-M Microcontroller Vendor Selection

For me, the available software and tools are the primary key decision factor why I select a particular silicon vendor. Without good software and tools, a microcontroller only ‘sand in plastic case’, even if it is the best microcontroller in the world. I do have several probably excellent microcontroller boards, and they are only getting touched by more durst over the months and years.

Undusted LPC824 Board

Undusted LPC824 Board

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MCUXpresso IDE: Unified Eclipse IDE for NXPs ARM Cortex-M Microcontrollers

There are many mergers going on in the industry, and one of the largest one was in 2016 the integration of Freescale Semiconductor with NXP Semiconductors, with both providing Eclipse based IDE’s to their customer base. Consequently, the company merger triggered a merger of the IDE’s, and last week NXP has released the result: the MCUXpresso IDE.

MCUXpresso IDE

MCUXpresso IDE

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Tutorial: Using Eclipse with NXP MCUXpresso SDK v2 and Processor Expert

To me, software and tools are by far more important than the microcontroller. Because the silicon is a ‘one time kind of thing’, where the software has to be maintained and working over a longer time. And at least my software usually needs to be ported to a new device, so portability and available software and tools are critical to me.

The combination of MCUXpresso SDK (formerly Kinetis SDK) and Processor Expert is unfortunately not supported by NXP. But I have found a way to get them work together in a nice way, and this article is about making that combination possible :-).

SDKv2 Project with Processor Expert

SDKv2 Project with Processor Expert which is supposed not to work together

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Better FreeRTOS Debugging in Eclipse

With debugging FreeRTOS applications in Eclipse, it is a big to have views available showing all the threads, queues, timers and heap memory allocation. One of the best Eclipse plugins are the one NXP provides for FreeRTOS: they are free of charge and give me pretty much everything I need. However, if you are not that familiar with FreeRTOS itself, here are a few tips to get more out of the plugins.

Better FreeRTOS Debugging in Eclipse

Better FreeRTOS Debugging in Eclipse

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