The Teensy boards are great, but as they are they are not really useful for real development, as they lack proper SWD debugging. In “Modifying the Teensy 3.5 and 3.6 for ARM SWD Debugging” I have found a way to get SWD debugging working, at that time with Kinetis Design Studio and the Segger J-Link. This article is about how debug the Teensy with free MCUXpresso IDE and the $20 NXP LPC-Link2 debug probe:
“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.
Back in March 2017, NXP had rolled the MCUXpresso IDE starting with Version 10.0.0. With the intent to unify the SDK, LPCXpresso, CodeWarrior, Kinetis Design Studio and Processor Expert into one unified and integrated set of tools. V10.0.0 was a good start. The MCUXpresso IDE V10.0.2 in July was more of a smaller update, and the Pin and Clock configuration tools were not integrated, no added tool for peripheral configuration.
A week ago the MCUXpresso V10.1.0 has been released which shows where the journey is going: an free-of-charge and code size unlimited Eclipse based integrated set of tools to configure, build and debug Cortex-M (Kinetis, LPC and i.MX RT) microcontroller/processor based applications.
I have used it for a week, and although many things are still new, I thought I’m able to give an overview about what is new.
I’m using many microcontroller in my projects. And a lot more are available out there in the ecosystem. Like many others, I tend to select what I am familiar with. But is this the correct approach to select the hardware and tools for a next project?
The ARM mbed USB MSD bootloader which is used on many silicon vendor boards has a big problem: it is vulnerable to operating systems like Windows 10 which can brick your board (see “Bricking and Recovering OpenSDA Boards in Windows 8 and 10“). To recover the board, typically a JTAG/SWD programmer has to be used. I have described in articles (see links section) how to recover from that situation, including using an inofficial new bootloader which (mostly) solves the problem. The good news is that ARM (mbed) has released an official and fixed bootloader. The bad news is that this bootloader does not work on every board because of a timing issue: the bootloader mostly enters bootloader mode instated executing the application.
More and more these very-very-high-resolution (UHD, Ultra-High-Density) notebook displays show up in my class rooms.These displays have 3100×1800 or even more pixels, making it great for watching high-resolution videos or for playing games (maybe?). But such a high-resolution makes many tools including Eclipse very hard to use, because the toolbar icons get so tiny that they are really hard to hit with a mouse cursor on Windows:
For several projects I’m using library projects: I build a library and then use that library in the other project. If I change something in a library, I want to run make both on the referenced libraries and rebuild my application if needed. If you don’t know how to do this, then read on… 🙂
(… actually it means workign around known Eclipse CDT bug too….)
ARM Cortex-M microcontrollers can have multiple memory controllers. This is a good thing as it allows the hardware to do multiple parallel memory read/writes. However this makes the memory map more complicated for the software: it divides the memory into different regions and memory segments. This article is about how to enable FreeRTOS to use multiple memory blocks for a virtual combined memory heap:
The tools and IDE market is constantly changing. Not only there is every year at least one new major Eclipse IDE release, the commercial tool chain and IDE vendors are constantly changing the environment too. For any ARM Cortex-M development, the combination of Eclipse with the GNU tool chain provided by ARM Inc. is the golden standard. But this does not mean that things can be easily moved from one IDE package to another.
While moving between Eclipse versions and GNU versions is usually not a big deal at all, moving between the Eclipse build tool integration is usually not simple. While the GNU MCU Eclipse plugins are widely used (see Breathing with Oxygen: DIY ARM Cortex-M C/C++ IDE and Toolchain with Eclipse Oxygen), the Eclipse based IDEs from the silicon vendors or commercial Eclipse toolchain vendors are using their own GNU toolchain integration. Which means the project files are not compatible :-(.
Sometimes it happens that arm-none-eabi-gdb complains about “no source file named” in the GDB console view in Eclipse when I debug a project with GDB:
FreeRTOS seems to get more and more popular, and I think as well because more and more debugger and Eclipse IDE vendors add dedicated debugging support for it.
A bootloader on a microcontroller is a very useful thing. It allows me to update the firmware in the field if necessary. There are many ways to use and make a bootloader (see “Serial Bootloader for the Freedom Board with Processor Expert“). But such a bootloader needs some space in FLASH, plus it needs to be programmed first on a blank device, so a JTAG programmer is needed. That’s why vendors have started including a ROM bootloader into their devices: the microcontroller comes out of the factory with a bootloader in FLASH. So instead writing my bootloader, I can use the one in the ROM.
And as with everything, there are pros and cons of that approach.
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
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
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.
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 🙂
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:
Eclipse for C/C++ (CDT) offers two different ways to get out of a debug session: 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.