An essential tool especially developing larger applications or distributed firmware is to use logging. This article presents an open source logging framework I’m using. It is small and easy to use and can log to a console, to a file on the host or even to a file on an embedded file system as FatFS.
FreeRTOS is pretty much everywhere because it is so simple and universal, and it runs from the smallest to the biggest systems. But it still might be that for the microcontroller device you have selected there is no example or SDK support for it from your vendor of choice. In that case: no problem: I show how you could easily add FreeRTOS plus many more goodies to it.
At the university we collect and recycle: bottles, batteries, glass, electronics and metal. Somebody did not have any use for a bunch of copper wires. I thought: there must be a better second live for it. This is how it looks:
I’m using the NXP Kinetis K22FN512 in many projects, either with the FRDM-K22F or on the tinyK22: with 120 MHz, 512 KByte FLASH and 128 KByte it has plenty of horsepower for many projects. The other positive thing is that it is supported by the NXP MCUXpresso IDE and SDK. I have now created an example which can be used as base for your own project, featuring FreeRTOS, FatFS, MinIni and a command line shell.
OpenPnP is a great open source framework for building a DIY SMT Pick&Place machine. But it does not stop there: It is possible to use OpenPnP with a commercial pick & place machine, for example the Charmhigh CHM-T36VA. This Chinese machine comes with its own controller software which works but is not that great. The good news is that it is possible to hack and retrofit the machine so it can run the much more powerful OpenPnP.
FreeRTOS has many cool features, and one is that it can report the CPU percentage spent in each task. The downside is that to get this kind of information some extra work is needed. In this article I show how to do this for the NXP i.MX1064.
Using the debugger to inspect the application data is a very convenient thing. But if the data grows and if the data set is large, it makes more sense to dump the data to the host and process it offline. GDB is the de-facto debugger engine and includes a powerful command line and scripting engine which can be used in Eclipse too.
Especially in a lab or classroom environment it is convenient to start with a template project, and then explore different ways to shape the project for different needs. As for any IDE of this world, this requires an understanding of the inner workings to get it right. So in this article I show how to copy, clone or rename properly an Eclipse ‘template’ project in the MCUXpresso IDE.
I love Eclipse because as an IDE it can do pretty much everything. Up to the point that some call it an ‘Eierlegende Wollmilchsau‘: something which can do anything. But with all the tools, menus and features, it can be daunting for a someone new to Eclipse. But the good news is: Eclipse is very versatile and can be customized to make it easier and simpler to use too. In this article I show how I’m tweaking it the way I want it, with just the menus and buttons I need:
Maker spaces and ‘FabLabs’ are popular and accessible in many areas. 3D printers are on the cheap, and powerful laser cutters are in the range of the fearless hobbyist. You can get dirty-cheap PCBs from China in less than a week (ok, probably not right now because of Corona virus) and it is easy to SMD solder parts these days with a DIY SMD PnP machine and OpenPnP. With the right equipment and skill set it is possible to build many cool projects. It is very rewarding and a great learning thing. Blog about it so other can learn too. And it even could get featured on Hackaday.
But: The risk is that someone might send you letter about a ‘Copyright Infringement’. Sadly, this is what happened to me for one of my recent projects. I don’t think that ‘take down’ letter was justified, but I learned a great deal what I should have done differently to avoid that situation. So in the end, it was a learning opportunity, which I believe is worth to share. In essence: what can a maker or educator do?
The tinyK22 board with the NXP K22FN512 is a bread-board-friendly small board with a 8 MHz external oscillator:
This tutorial is about how to use the NXP MCUXpresso Clock configuration and configure the board to the maximum clock frequency of 120 MHz. The same steps apply to many other boards, including the FRDM-K22F one.
The gnuplot is a versatile and powerful tool to plot and visualize all kind of data. I wish there would be a plugin for it in Eclipse. But as this is not (yet?) the case, here is how I’m using it with gdb and Eclipse, using the MCUXpresso IDE as example.
Most of my projects are using FreeRTOS, and I’m using different Debug Probes (SEGGER, P&E and LinkServer) to debug NXP devices.
The NXP LinkServer debug connection is able to show the RTOS threads in Eclipse/MCUXpresso IDE which is incredibly helpful:
However, by default this is turned off. In this article I show how to turn this on by default.
Eclipse with its CDT managed Make system makes it easy to build projects, because it can handle a lot of the background tasks and settings between the project and the build setting. It can get a bit difficult if I want to include a library or other sub-source project for which I have to add extra compiler #define or add extra includes path settings.
This article show the different ways I have found to make such imports (and exports) easier.
One great feature of Eclipse is its built-in spell checking engine. So no more excuses are possible for typos in the source code ;-). Eclipse scans the source code in the background and offers to correct it:
When using an RTOS like FreeRTOS, sooner or later you have to ask the question: how much time is spent in each task? The Eclipse based MCUXpresso IDE has a nice view showing exactly this kind of information:
For FreeRTOS (or that Task List view) to show that very useful information, the developer has to provide a helping hand so the RTOS can collect this information. This article shows how this can be done on an ARM Cortex-M.
In “Seeed Studio Arch Mix NXP i.MX RT1052 Board” and “Debug and Execute Code from FLASH on the Seeed Arch Mix NXP i.MX RT1052 Board” I have used the NXP LPC-Link2 to debug the Seeed Arch Mix board with the NXP i.MX RT1052, because the SEGGER J-Link does not work out-of-the box with the i.MX RT using QSPI Flash. This article shows how the J-Link connection can be changed from HyperFlash to work with QSPI Flash.
In “Eclipse JTAG Debugging the ESP32 with a SEGGER J-Link” I used a SEGGER J-Link to debug an ESP32 device with JTAG. I looked at using one of the FTDI FT2232HL development boards which are supported by OpenOCD. The FT2232HL is dual high-speed USB to UART/FIFO device, and similar FTDI devices are used on many boards as UART to USB converters. With OpenOCD these devices can be turned into inexpensive JTAG debug probes. This article shows how to use a $10 FTDI board as JTAG interface to program and debug the Espressif ESP32.
Bootloaders are a fine thing: With this I can load any applications I like. Power comes with some complexity, and a bootloader alone is a complex thing already. But this applies to the application part too: I need to link the application to a certain offset in the memory space so it can be loaded by the bootloader, plus the application typically needs to add some extra information to be used by the bootloader. This article describes how to build a bootloader application with Eclipse (MCUXpresso IDE) using the MCUXpresso SDK.