GNU Link Time Optimization finds non-matching Declarations

By default, the GNU compiler (gcc) optimizes each compilation unit (source file) separately. This is effective, but misses the opportunity to optimize across compilation units. Here is where the Link Time Optimization (LTO,  option -flto) can help out: with a global view it can optimize one step further.

The other positive side effect is that the linker can flag possible issues like the one below which are not visible to the compiler alone:

type of '__SP_INIT' does not match original declaration [enabled by default]
Warning by LTO

Warning by LTO

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Do you Speak Klingon? How to change the Eclipse IDE UI Language with Babel

We in Switzerland are proud about the fact that our country has four official languages: Italian, French, German and Romansh. Most of Swiss people speak at least two of them, plus the inofficial fifth language (English).

Eclipse is even better than that and speaks 46 different languages. If you are not happy with the default language, try out Babel! And yes, Eclipse has a language pack for Klingon too:

Babel Language Packs in Klingon

Babel Language Packs in Klingon

🙂

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Sneak Preview: DIY SMT Pick & Place Machine with OpenPnP

I apologize: I have not been blogging much in the past weeks :-(. One reason is that I’m working on a DIY SMT/SMD Pick&Place machine which keeps me busy most of my spare time :-). I admit that this project is not finished yet, but now is the time I can give a sneak preview: a SMD/SMT pick and place machine:

Pick&Place Machine

Pick&Place Machine

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Tutorial: CRC32 Checksum with the KBOOT Bootloader

In “Flash-Resident USB-HID Bootloader with the NXP Kinetis K22 Microcontroller” I presented how I’m using the tinyK22 (or FRDM-K22F) with a flash resident USB HID bootloader. To make sure that the loaded application is not corrupted somehow, it is important to verify it with a Cyclic redundancy Checksum (CRC). The NXP KBOOT Bootloader can verify such a CRC, but how to generate one and how to use it is not really obvious (at least to me), so this article explains how to generate that CRC.

CRC Values for KBOOT

CRC Values for KBOOT

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Performance and Runtime Analysis with FreeRTOS

One of the great things with the FreeRTOS operating system is that it comes with free performance analysis: It shows me how much time is spent in each task. Best of all: it shows it in a graphical way inside Eclipse too:

FreeRTOS Runtime Information in Eclipse

FreeRTOS Runtime Information in Eclipse

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Troubleshooting Tips: Failed Debugging with GDB

Three years ago I published “Debugging Failure: Check List and Hints” and unfortunately this article is one of the most popular ones: obviously debugging problems are very common. Debugging with GDB works usually fine, but if things are failing, then it can be hard to find the cause for it. Recently I have been asked to check some failures, so here are two more hints about what could go wrong…

Error while launching command: arm-none-eabi-gdb --version

Error while launching command: arm-none-eabi-gdb –version

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McuOnEclipse Components: 26-Dec-2017 Release

I’m pleased to announce that a new release of the McuOnEclipse components is available in SourceForge., which is supposed to be the last release for 2017 :-). This release features several smaller bug fixes, the new FreeRTOS V10.0.0 and extended device support.

SourceForge

SourceForge

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New FreeRTOS V10.0.0: Amazon, Segger SystemView and Percepio Tracealyzer

“Amazon FreeRTOS – IoT operating system for microcontrollers”: The announcement of FreeRTOS V10.0.0 was one of the biggest news last week for me. Not only is there now a Version 10, the bigger news is that FreeRTOS is now part of Amazon. Wow! Now this explains why Richard Barry (the founder behind FreeRTOS) was kind of hiding away for about a year: he joined Amazon as a principal engineer about a year ago. I think we all have to wait and see what it means for FreeRTOS.

Amazon FreeRTOS

Amazon FreeRTOS (Source: Amazon Web Site)

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SQUIX ESP8266 based E-Paper WiFi Weather Station

I’m a fan of all kind of weather stations. When Daniel Eichhorn twittered about his new version using an E-Paper display module, I immediately preordered one. I decided to build a station with a custom enclosure, so here is my version of a 3D printed version, featuring magnets so it can be attached to the fridge:

E-Paper Weather Station

E-Paper Weather Station

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McuOnEclipse Components: 25-Sept-2017 Release

I’m pleased to announce that a new release of the McuOnEclipse components is available in SourceForge. In this release more ARM Cortex devices/vendors are supported with different SDKs, plus it comes with several FreeRTOS enhancements for debugging highly optimized code.

SourceForge

SourceForge

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Tutorial: Makefile Projects with Eclipse

The benefit of an IDE like Eclipse is: it makes working with projects very easy, as generates make files and it takes and automatically manages the make file(s). But sometimes this might not be what I want because I need greater flexibility and control, or I want to use the same make files for my continues integration and automated testing system. In that case a hand crafted make file is the way to go.

One thing does not exclude the other: This article explains how to use make files with Eclipse with similar comfort as the managed build system in Eclipse, but with the unlimited power of make files:

Makefile Project with Eclipse

Makefile Project with Eclipse

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McuOnEclipse Components: 09-July-2017 Release

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

  • Complete refactoring for 1-Wire stack and DS18B20 temperature sensor components
  • Added HID Joystick device class to the FSL_USB_Stack
  • New SDK_Timer component to work with Kinetis SDK
  • New ST756P LCD driver component
  • New TSL2561 digitial temperature sensor driver
  • Added ReadByte() and WriteByte() GenericI2C functions
  • Added 64bit mapping functions to Utility
  • added configUSE_NEWLIB_REENTRANT and newlib reentrancy support to FreeRTOS
  • Pull resistor support for SDK_BitIO
  • Many smaller bug fixes and enhancements
SourceForge

SourceForge

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GNU Code Coverage on Embedded Target with Eclipse Neon and ARM gcc 5

For a research project, we are going to send a satellite with an embedded ARM Cortex microcontroller into space early next year. Naturally, it has to work the first time. As part of all the ESA paperwork, we have to prove that we tested the hardware and software thoroughly. One pice of the that is to collect and give test coverage evidence. And there is no need for expensive tools: Free-of-charge Eclipse and GNU tools can do the job for a space mission 🙂

Eclipse with Coverage Views

Eclipse with Coverage Views

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Adding GNU Coverage Tools to Eclipse

The GNU tools include powerful utilities to collect coverage information. With coverage I know which lines of my code have been executed, which is a very useful test metric. The GNU coverage tools are commonly used for Linux applications. But to my surprise not much for embedded application development, mostly because it requires a few extra steps to have it available? Why not using free and powerful tools for improving software quality? This article explains how to install the GNU gcov tools into the Eclipse IDE.

gcov with Embedded Target

gcov with Embedded Target

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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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MCUXpresso IDE: Blinky the NXP LPC800-DIP Board

During Embedded World 2017 in Nürnberg I was lucky to get a handful LPC800-DIP boards. To get all students who were lucky to get one, here is a tutorial to make that very exciting ‘blinky’ application on that board:

Blinky on the NXP LPC800-DIP

Blinky on the NXP LPC800-DIP

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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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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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Enable Secure Communication with TLS and the Mosquitto Broker

MQTT is a lightweight  and broadly used internet protocol (see “MQTT with lwip and NXP FRDM-K64F Board“). And probably the majority of IoT applications today are using Mosquitto as server (or ‘broker’ in MQTT language). By default, Mosquitto is using a protocol without encryption. In “Introduction to Security and TLS (Transport Layer Security)” I have covered the basics and needs for encryption. This article is about how to enable Mosquitto and clients to use the TLS protocol.

TLS Handshaking with certificates and keys

TLS Handshaking with certificates and keys

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