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:
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.
FRDM-KL03Z with ROM Bootloader
And as with everything, there are pros and cons of that approach.
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:
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?
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.
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.
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 which is supposed not to work together
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:
One of the biggest road blocks (beside of closed source) using the BLE (Bluetooth Low Energy) stack from NXP is that it requires expensive tools to compile and build the stack. The good news is that I have now the NXP BLE stack for the Mikroelektronika Hexiwear ported to Eclipse and GNU gcc build tools for ARM 🙂
But one issue I have faced several times is that the board works fine while debugging and connected and powered by a host machine, but does not startup sometimes if powered by a battery or started without a debugger attached. I have found that the EzPort on the microcontroller is causing startup issues.
As a standard procedure, I add some console functionality to my embedded applications. That way I have a command line interface and can inspect and influence the target system. One interesting hardware feature of ARM Cortex-M is Single Wire Output (SWO): it allows to send out data (e.g. strings) over up to 32 different stimulus ports, over a single wire.
Playing with RFID and NFC is definitely fun :-), and they are everywhere! For a research project I’m exploring different RFID tags and solutions. I several types around for a long time, but never found the time to actually work on it, so last nightI thought I give it a try, and I have it working with GNU ARM and Eclipse, powered by the NXP FRDM-K64F board 🙂
I kind of hoped that after “Why I don’t like printf()” and all my other articles about printf and semihosting, that topic would be 200% handled and I won’t have to deal with any more. Well, I was wrong and underestimated how the Kinetis SDK is interfering with semihosting. And I underestimated how many of my readers are still using semihosting (even as there are other and better alternatives), so I keep getting questions and requests for help. That’s ok, and I hope I can help :-).
So here is yet again another post about how to turn on semihosting with Eclipse, GNU ARM Embedded and the Kinetis SDK v2.0. This time with the FRDM-K64F board:
Getting a board from a distributor like Farnell/Element14/Mouser (add your own distributor) means that chances are high that the default firmware on it is written years from now because the inventory has not been updated, or because boards are still produced with that original firmware (because of testing?). So what happens if I use board with a firmware developed pre-Windows 8/10 area?
Freshly Unboxed NXP FRDM-KL25Z Board
It might work, but chances are high that the bootloader and firmware is not ready for the ‘modern age’, and as a result the board might be bricked. If you still have a Windows 7 machine around (I do!), you are lucky. If not, then you need to read this article….
More and more of my students are using Microsoft Windows 10 machines, and my computer has been upgraded to Windows 10 a couple of week ago too. From my work and experience, a new operating system causes always some challenges, and Windows 10 is no difference. And no, this is not about Microsoft vs. Apple vs. Linux, this post is about addressing a potential and painful problem which I have observed with Windows 10 machines, and to my understanding it could happen with any other operating system too. The problem is that somehow on several student machines the bootloader and OpenSDA application on their FRDM boards did not work any more.
FRDM-K64F (top) programming the OpenSDA Bootloader (bottom)
A bootloader shall be small and concise. I very much like bootloaders which do not need a ‘special’ program on the host, so I prefer a simple terminal for this. While porting my serial bootloader to the NXP FRDM-K64F board, I have found RealTerm which offers a lot of cool features:
Sometimes it is very convenient to load a new firmware to a board without the need for a hardware debugger. This is usually done with a bootloader. The NXP Freedom and Tower evaluation boards have on-board debug device/microcontroller (OpenSDA) which can load different firmware implementations like CMSIS-DAP/mbed, P&E Multilink or a Segger J-Link OpenSDA applications. Both mbed and P&E implemenations support to program the board with drag&drop: simply send a file to a virtual MSD (Mass Storage Device) to get it programmed. The latest Segger OpenSDA firmware has this ability added now too: Programming the board with a virtual MSD device: