Docker or Development Container are great for isolation. And they work very well with things outside which are TCP/IP based. But most debug probes are USB only. Docker container don’t work well with USB. In Remote Debugging with DevContainer and VS Code, I showed how to use USB based debug probes. I demonstrated using them with an IP connection. In this article I show how Windows USB devices can be used from a container, with the help of usbipd.
I recently upgraded from Win10 to Win11. Windows 10 was not great for building performance compared to Linux. And I feel that with Windows 11 things got worse too.
Dev Container in VS Code uses docker-based environments. This enables me using a full-featured development environment, with isolated dependencies. This is especially very useful for development in the embedded systems space. There I have to use many different SDKs, toolchains and libraries. Using Dev Containers is super easy. But file I/O operations with building etc/is not that great.
The solution is to use a Docker Volume with VS Code and Dev Container:
The Rust programming language is making its way into different areas: Rust gets added to the Linux Kernel. I see an increasing interest for using Rust in embedded projects. And Rust is used for embedded tools. I noticed this with the latest LinkServer v25.09 release: there is a new tool included in the package, rblhost.
rblhost on crates.io
The release note just mentioned:
- Switched to using rapid blhost (rblhost) utility.
This triggered my interest, and actually that utility is implemented in Rust :-).
Today’s projects and systems get more and more complex. Many systems include multiple MCUs, connected with a field bus or network, for example CAN. For example there can be up to 70 CAN nodes in modern cars. Such larger and connected systems are a challenge for debugging.
Traditional hardware debugging requires a hardware debug probe, connected with a dedicated SWD/JTAG debug cable to the target device. This needs dedicated pins on the target device plus physical access to the device itself. In many cases, this is not possible in the final product. The hardware debug probes, cables, pins and high speed signals are costly. And worse they can introduce new problems and are prone to interference.
If there is a field bus like CAN connecting all the MCUs, why not use it for hardware debugging? Hardware debugging meaning programming the FLASH memory, halt the MCU, inspect the memory and registers, and step through the code?
Cortex-M Hardware Debugging over CAN
Yes, we can! With the help of a rather unknown hardware feature on ARM Cortex-M devices. We can use the ARM DebugMonitor Interrupt to control and debug the target system. As we would use a JTAG/SWD connection. Instead, we use the CAN bus :-).
The MetaClockClock is a clock made of clocks. It consists of multiple dual-shaft stepper motors, arranged as a matrix of 5×12 analog clocks. Each clock has two motorized hands that can move independently. The clock can tell the time, but in a unconventional way. The entire matrix creates a meta-display that shows the time or other information. Between the updates, the hand can do coordinated, choreographed movements.
The clock hands are laser cut acrylics with get light up with a LED ring around the clock.
This article describes the build with CNC cut oak enclosure, laser-cut parts and 3D printed items.
Usually, I run applications in the micro-controller FLASH memory. But for a CI/CD or testing environment that is not the best choice.
It is possible to have a ‘RAM target’, where the application is running in RAM instead of FLASH memory. This has the advantage not to ‘wear-out’ the FLASH memory. Plus loading and running in RAM is faster. This makes having RAM targets especially useful for testing.
In this article I’m using the NXP LPC55S16-EVK board, but any other target or board is applicable.
Remote debugging an embedded target is very useful: I don’t need a direct debug probe or USB cable connection. Instead, I’m using a network connection (wired or even wireless) over TCP/IP to talk to the debug probe and target. That way I can place the debug probe and target system away from my desk.
In Remote Debugging with USB based JTAG/SWD Debug Probes I showed how normal USB based debug probes can be used. This approach uses a remote host machine (e.g. desktop machine or notebook). This approach is still expensive, not scalable and the host machine needs a lot of space too.
So what if I use a Raspberry Pi instead? The RPi is small, inexpensive and ideal for such a task. Additionally, I can easily use it to build a test or debug farm. In this article, I show the use of the Raspberry Pi for remote debugging. A sub $20 or embedded target debug probe can be employed.
Raspberry Pi with NXP MCU-Link for Embedded Target DebuggingContinue reading →
This is the second part describing how to use DevContainer for embedded applications with VS Code.
In Optimizing Embedded Development with VS Code and DevContainer I use VS Code with a docker ‘development’ container. The container is created with a recipe to install the development tools and SDK. With VS Code and DevContainer I have the same developer experience as I would develop locally on the host.
One thing not addressed in that earlier article is debugging. Using USB debug probes like a SEGGER J-Link or NXP MCU-Link is a challenge inside a container. This applies to any other debug probe as well.
The solution is to transform an USB based debug probe into one with a network connection: