I’m using the RS-485 field bus in many of my projects: it is very reliable and robust, and easy to implement. And with ModBus there is standardized protocol used in building automation or industrial control applications. For example I’m using the protocol to communicate between battery systems and an EV Charger.
In this article I show you with an example, how the NXP LPC55S69 can be used with RS-485.
Continue readingIt is August 1st, and Switzerland is celebrating its National Holiday. Rather cold and rainy, so this gets me some time to catch up on things. The preparation for the coming university semester in September is in full swing, and I have the honor to take over building up a new Master of Science in Engineering education module. In the existing courses I teach on the topic of embedded systems, I do use devices and MCUs from vendors like Broadcom, NXP, STM, Nordic, Raspberry Pi and Espressif. This not only means different SDKs, but different IDEs with different debug probes.
Eclipse has been the common factor in the mix with all these, and with all the pros and cons, it worked very well. With NXP having released support for Visual Studio Code, adding an announcement, and other vendors going into the same direction, I took the decision that I want to migrate my lab and lecture infrastructure to VS Code.
Continue readingThe combination of the NXP MCUXpresso IDE with the NXP MCU-Link Pro debug probe implements a nifty power and energy measurement tool (see New “MCU-Link Pro”: Debug Probe with Energy Measurement). The eclipse based IDE provides a dedicated view to inspect the data collected. It can export and import data, but it is in a binary format. In this article I present a way to export and then convert the data into .csv or any other format for processing or visualizing it in different ways.
Using an open source command line tool, the binary data gets converted into a csv format, which then can be consumed by many tools, e.g. gnuplot.
If one is using a dedicated logger module like the McuLog, then you don’t have to worry or care about timestamp support. But if your application is using normal printf() calls for for logging purpose, you will face issues to adding timestamps to it. You might consider to change all prinft() calls. This might be a lot of work, or not possible in all cases if you cannot change the source code.
But there is a really cool feature of the GNU linker to solve that problem. It allows to ‘wrap’ around any symbol or function, including the ones in the standard library. That way I can add my mode to the printf() code as a wrapper, for example adding a timestamp for every call.
In the example below you can see this in action:
In this article I’ll show how you can wrap any function with custom code.
Continue readingIn many of my embedded projects I need persistent data or storage for settings. If using an SD card, then FatFS is usually my choice for the file system. But if using an external FLASH memory device, then my preferred choice is usually LittleFS: it is a little fail-safe filesystem, designed for micro-controllers, which I’m using with external flash memory devices.
In the case where there is enough MCU flash, or if there is no external FLASH device available in a design, it can use the MCU internal FLASH as storage storage too. This is the topic of this article:
The choice of IDE is sometimes given by the available tools at hand. And sometimes it is a preference of the look and feel. Or maybe just what one is used to use. And sometimes small changes can make a big difference too.
For example, when I’m starring at my code for hours, a nice font can make all the difference. A cool and nice feature of fonts are ‘Ligatures‘. Maybe you can you can spot them in the following screenshot?
Embedded hardware comes with limitations, and one if it is the given number of hardware breakpoints. Depending on your MCU, 4 or only 2 hardware breakpoints are available, making debugging and stepping in read-only memory (FLASH) a challenge.
Did you know that one can have ‘unlimited’ number of breakpoints in FLASH, with the help of GDB? This is very useful for extended debugging, or if you want to use breakpoints for testing?
Continue readingSometimes it makes sense to write everything in assembly, even these days. For example if using a tiny microcontroller. Or just if one just don’t need all the productivity of the C/C++ tools. And it is a good educational experience: getting hands-on on the lower levels.
The Project Explorer view in Eclipse shows the projects and their files. By default, some files are hidden. But I can change that, and I can hide and unhide files based on rules:
GDB is the de-facto debugging engine and debug connection for micro-controllers these days: it is versatile and with its client-server architecture very flexible and powerful, and pretty much every debug probe and vendor (PEMICRO, SEGGER, OpenOCD, pyOCD, …) offers it. But a GDB server or command line implementation was not available for the NXP LinkServer family of debug probes (LPC-Link, MCU-Link, MCU-Link Pro). This has changed now: LinkServer is available as command line tool and can be used as GDB Server:
With the new LinkServer package I do not only get a gdb server implementation: I have now a command line tool I can use for automation and all kind of different things: programming boards, erasing flash, and so on.
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MCU on Eclipse 