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 🙂
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.
In “Cycle Counting on ARM Cortex-M with DWT” I have used the ARM DWT register to count the executed cycles. With the MCUXpresso IDE comes with a very useful feature: it can capture the ARM SWO (Single Wire Output) trace data. One special kind of trace data is the ‘cycle counter’ information which is sent through SWO.
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:
Eclipse for C/C++ (CDT) offers two different ways to get out of a debug session: Terminate and Disconnect:
Terminate and Disconnect
The terminate and disconnect behaviour is not standardized, and varies between Eclipse distributions and debug connection. This article is about how things are handled in MCUXpresso IDE, and how I can influence the behaviour.
I’m using Eclipse based IDE’s to develop and debug my embedded applications. This works great, as Eclipse has all the necessary tools to edit, build and debug it. But when it comes just to download/flash a binary to the board, then things are pretty much specific to the tools used. With the advent of the new MCUXpresso IDE, here is how that Eclipse IDE can be used for this.
The MCUXpresso IDE (see “MCUXpresso IDE: Unified Eclipse IDE for NXPs ARM Cortex-M Microcontrollers“) has one great feature: it includes debug support for the popular LPC-Link2 debug probes. That way I have yet another powerful debug probe with extra features for ARM based boards. That LPC-Link2 circuit is present on many LPCXpresso boards from NXP. So why not using it to debug it my custom hardware?
Looking for a small, inexpensive ($25-30) ARM development board (say 120-180 MHz ARM Cortex-M4 with FPU, 512kB-1MB of FLASH and 256 KByte of RAM? Then have a look at the Teensy 3.5 and Teensy 3.6 by PJRC/Paul Stoffregen:
Teensy 3.5 with NXP K64F ARM Cortex-M4F
The only problem? it is not possible to debug it :-(. At least not in the traditional sense. This article is about how to change the board to use it with any normal SWD debugging tool e.g. Eclipse and the Segger J-Link :-).
Many of my currently active projects are using Kinetis Design Studio (KDS) V3.2.0 from NXP (I have published many of my projects on GitHub). Now with the advent of the MCUXpresso IDE (see “MCUXpresso IDE: Unified Eclipse IDE for NXPs ARM Cortex-M Microcontrollers“), I have migrated several projects from KDS to MCUXpresso. This post is about how to easily get KDS projects ported and running in MCUXpresso IDE.
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.
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.
Questions from students or readers of my articles are a great source for all kind of articles. And here is the ‘question of this week’: “What is realtime debugging”?
It’s a good question because the topic of ‘realtime’ and ‘debugging’ was a topic in the lectures this week. So this question gives me the opportunity to combine the two things of ‘realtime’ and ‘debugging’, I love it :-).
Good news for everyone using Eclipse, FreeRTOS and Percepio Tracealyzer: Percepio has released an Eclipse plugin which makes snapshot tracing very easy and convenient using the a GNU gdb debugger in Eclipse like Kinetis Design Studio:
P&E has a new version of their GDB/Eclipse debug plugins available on their Eclipse update site, and it comes with to great features: Real Time Expressions (show variables while target is running) and FreeRTOS thread awareness 🙂
For a CubeSat project we only have a single board available. But multiple universities and developers need to have access to that board for developing and debugging the firmware. We cannot easily ship around the board: that takes a lot of time and during shipment nobody can use the board.
There is a nice feature in the Segger J-Link software which allows to share the debug connection over the network: the J-Link Remote Server. It even works nicely between different networks without complicated firewall setup:
Some ARM Cortex-M have a DWT (Data Watchpoint and Trace) unit implemented, and it has a nice feature in that unit which counts the execution cycles. The DWT is usually implemented on most Cortex-M3, M4 and M7 devices, including e.g. the NXP Kinetis or LPC devices.
The concept of Linux (Open Source, broad developer base and broad usage) is a success story. While there is a lot of diversity (and freedom) in the Linux world, Linux is Linux and again Linux :-). And the world has (mostly) standardized on Linux and its variants on the high embedded system side.
“The Linux Foundation Announces Project to Build Real-Time Operating System for Internet of Things Devices. Open source Zephyr™ Project aims to deliver an RTOS; opens call for developers to help advance project for the smallest footprint IoT devices.“
Ζεφυρος (Zephyros) is the Greek good of spring and the west wind. Obviously this inspired the logo for the Zephyr project: