Automated On-Target Testing with J-Run’s –args Feature

SEGGER has released a new version of their J-Link tools suite. That suite includes the J-Run utility which loads, executes and monitors the output of the target. Output can be with RTT (Real-Time Transfer) or semihosting. This makes it useful for automated tests with CMake and CTest:

CTest with J-Run

What has been added from the V7.98g release is the ability to send arguments to the running application using the --args command, for example with CMake/CTest:

set (RUNNER_CTEST_COMMAND "$ENV{SEGGER_PATH}/JRun" --verbose --device LPC55S16 --silent --rtt -if SWD)

add_test(
NAME Led_1
COMMAND ${RUNNER_CTEST_COMMAND} --args "Led_1" ${TEST_EXECUTABLE}
)

Like applications running on the host, I can now pass arguments to the running application. This is useful to set up the target, or to tell which kind of tests to run.

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Eclipse Workspace Sharing: Team Project Set Export and Import

In my Eclipse workspace I have many projects, from multiple git repositories.

Eclipse (MCUXpresso) with projects from multiple repositories

How can I share a list of projects, say in a development team? As we all should know: the Eclipse workspace (.metadata folder) should not be shared. So how can I share it? There is a cool feature in Eclipse which does exactly that. It shares a configurable set of workspace projects, even if they are on different git repositories.

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How to Use SystemView Data Plot Feature for Real-time Data Visualization

There is a new feature in the SEGGER SystemView: the ability to plot any data provided by the application, for example sensor data or any other useful data:

SEGGER SystemView with Data Plot
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Tutorial: GNU Coverage with C++ for Embedded Applications

In an earlier article I explained how to generate GNU coverage information, for an embedded application written in C.

In this article, I show the steps and configuration needed to use GNU gcov targeting an embedded application with C++.

GNU gcov Coverage with C++ Application
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How to Use GNU Coverage (gcov) in a Freestanding Environment for Embedded Systems

The GNU Coverage (gcov) is a source code analysis tool, and is a standard utility in the GNU gcc suite. It works great in a hosted environment (e.g. Linux or Windows), where you have plenty of resources and a file system. But the gcov tools is relevant and usable for restricted embedded systems too. I have used it for years with the help of debug probes and file I/O semihosting. But semihosting does not come for free, depends on a library with support for constructors and destructors, plus relies on file I/O.

Fortunately, there is a way to use gcov without debugger, semihosting, file I/O and special system initialization: using a freestanding environment:

gcov in freestanding environment with embedded target

This article explains how to collect coverage information using a data stream for example over UART or USB-CDC. Key benefits are less code side, no need for a debugger or on-target file system, improved performance, better automation and flexible data collection.

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MCUXpresso IDE v11.10: Easy MCU-Link Firmware Update with Eclipse

A new eclipse-based NXP MCUXpresso IDE v11.10 is available With this new release, it includes an even easier firmware update mechanism for the MCU-Link (LinkServer) debug probes.

MCU-Link based debug probes with a FRDM-K22F board
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Using NXP i.MX RT685 with pyOCD: Device Support and Debugging Configuration

The NXP i.MX RT685 is an interesting device: an ARM Cortex M33 with a Cadence Xtensa audio DSP. To explore the features of the device, I’m using the NXP EVK board:

pyOCD with NXP i.MX RT685

I have used it so far with the on-board MCU-Link debug probe and LinkServer. This article describes how I have added pyOCD as debug interface for the RT685, as well how to patch and use custom DFP (Device Family Pack) files with pyOCD and Eclipse.

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Low-Power Optimization Techniques for ARM Cortex-M Microcontrollers

Europe is currently facing an ‘Energy Crisis,’ and ‘Sustainability’ is a popular topic among companies. However, embedded engineers go beyond talking—they take action and make tangible changes in the world. With the increasing use of electronic devices, minimizing their energy and power consumption is crucial. Optimizing systems for deep low power or deep low energy is a challenging task. Nonetheless, as I will demonstrate in this article, it is possible to reduce energy consumption by a factor of 100 or more. This article provides a brief overview of the foundational concepts and then applies them step-by-step to an ARM Cortex microcontroller.

Measuring on-board LPC804 with MCU-Link Pro
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Building Eclipse Projects with custom external Shell Scripts

Eclipse includes many ways to build a project. One of it is the built-in builder which makes it super easy. And for more complex building needs I can use an external make (see Tutorial: Makefile Projects with Eclipse) or cmake or combination of multiple ways (see Building a Triumvirate: From Eclipse CDT to CMake, CMD and Visual Studio Code).

There is yet another use case how to easily tweak the build process in Eclipse: using a script file in the project to be used as the ‘compiler’:

External Build Script

That way I can do all kind of custom steps (analysis, re-formatting, static checkers, …) for each file compiled.

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MCU-Link-MR v0.2 Drone and Robot Debug Probe with UART-2-USB Bridge

This week I have received the new PCBs for the MCU-Link MR for drones and robots and have populated the parts on the PCB, and it works fine as UART bridge and debug probe for the PixHawk i.MX RT:

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