Semihosting with VS Code on RP2040

With semihosting I can use standard I/O function like printf() and I can read and write data on the host through the debug connection. If used with care, this is a great feature especially for unit testing.

Raspberry Pi Pico-W (RP2040) board
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Global Constructors and Destructors with C (not C++)

In the OOP world, global objects get initialized with a constructor and destroyed at the end with a destructor. Interestingly, the GNU gcc has attributes to mark functions as constructor and destructors, which can greatly simply system startup and shutdown, even if not using C++.

C Function marked as Constructor and called before main()

With the GNU gcc compiler, I can mark functions with an attribute, so they get called before entering main() or after exit of main(). The attribute works both in C and C++, but it especially useful in C to initialize modules in an automated way.

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CI/CD for Embedded with VS Code, Docker and GitHub Actions

“Our highest priority is to satisfy the customer
through early and continuous delivery
of valuable software.”

Agile Manifesto, https://agilemanifesto.org/principles.html

It is interesting to see that modern tools and agile development workflows are getting more and more into the embedded world. CI/CD is a strategy where code changes to an application get automatically integrated, tested and released automatically into a production environment.

VS Code with CI/CD
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Selecting J-Link Debug Probe by Nickname

I have lots of hardware and debug probes on my desk, and I discussed using nicknames for debug probes to better identify them.

‘Green’ and ‘Yellow’ Robots and J-Link Probes

So far so good. At that time of the previous article, it was possible to assign nicknames to J-Link debug probes, but not to use the nickname instead of the USB serial number. Well, SEGGER was fast again, and responded with a new J-Link software pack version 7.92d which implements that features: I can now use the nickname to connect to a debug probe :-).

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New SEGGER J-Link-OB LPC4322-based Firmware with Target Power

Sometimes I have a wish. Not every time it gets fulfilled. But this time I’m lucky and happy developer. A few days ago I wrote about the LPC4322-based SEGGER OB (on-board) J-Link firmware. It works great, but the board requires another USB cable to power the target board.

Rolf Segger contacted me, and a few days later I had a J-Link firmware with a ‘power-on’ feature:

That way, only one USB cable is needed. All what you need to do is to update the firmware.

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VS Code: Virtual Environments for Embedded Development with Conda

Developing for an embedded target means using a certain version of GNU compiler, debugger and other tools. The challenge gets bigger if working with multiple different tool chains and environments.

Conda in VS Code

Conda is package, dependency and environment management tool. While it is heavily used for Python and Data Science development, it is surprisingly working very well to set up and managing environments for embedded development. Conda is great for managing non-Python dependencies and setups.

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Upgrading LPC4322-based Debug Probe Firmware on RT10xx

Going with the factory default can be fine. But an upgrade could give a performance boost plus added functionality. Many of the NXP i.MX RT evaluation boards have an LPC4322 based debug circuit on it. One example for this is the i.MX RT1010 board.

NXP i.MX RT1010 EVK

On such boards, one of the first steps I do is: upgrading the firmware and change it to a better option: improved speed, SWO support plus avoiding issues with the USB MSD device.

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VS Code: Importing pre-v2.13.0 MCUXpresso SDK Projects

In my previous article I showed how to import, build and debug MCUXpresso SDK projects in VS Code. In my lectures and labs we are using a robot based on the NXP Kinetis K22FX512 ARM Cortex-M4F microcontroller, and there is only the v2.13.0 SDK available.

INTRO Sumo Robot
Sumo Robot with K22FX512

The software on the robot uses the latest NXP MCUXpresso SDK v2.3.1. The he Eclipse based MCUXpresso IDE 11.8.0 works fine with all the 2.x SDKs, up to the latest 2.13.0 one.

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Solving Linker Error: “cannot move location counter backwards”

Upgrading to a newer GNU toolchain always has its risks. That’s why I always recommend to stay on a given toolchain for production code.

But sometimes one needs to upgrade, or gets a code or project that works in one environment, but not in another. Today I have run into a problem with code read-out projection:

Disabled Automatic Placement of Code Read Protection

Well, the code read-out protection is not the root of the problem, but a good example why problems could occur.

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Integrating Solar-Surplus-Charge-Controller into EV Wallbox

Solar panels and electrical vehicles become more and more common in Switzerland. Ten years ago I installed solar panels. To use the available solar energy, the electrical vehicle charging box has been augmented with an open source charge controller. The controller monitors the building energy usage and adjusts the current using the Modbus connection to the charger.

Integrated Charger Controller into Wallbox
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