Coming out of a project meeting Friday evening, the following wisdom came to my mind:
“The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair.” – Anonymous
P&E has a new version of their GDB/Eclipse debug plugins available on their Eclipse update site, and it comes with to great features: Real Time Expressions (show variables while target is running) and FreeRTOS thread awareness 🙂
I’m a big fan of ‘low-and-slow’ cooking, and that’s why I love my BBQ Smoker. That smoker is great for Ribs, Brisket or Pulled Pork. But it is not ideal for other pieces of meat. After doing some research, this weekend I tried something differently: “Sous-Vide”. The result is delicious: this is by far the best steak I’ve ever cooked :-).
For a CubeSat project we only have a single board available. But multiple universities and developers need to have access to that board for developing and debugging the firmware. We cannot easily ship around the board: that takes a lot of time and during shipment nobody can use the board.
There is a nice feature in the Segger J-Link software which allows to share the debug connection over the network: the J-Link Remote Server. It even works nicely between different networks without complicated firewall setup:
Maybe you remember my recent post “Schwanau on Ice” with walking on the frozen Lake Lauerz? I mentioned in that post that there are natural gas bubbles caught under the ice. There is a long (and dangerous!) tradition to burn that gas. That this is really dangerous shows this a short video going viral on ‘WhatsApp’ today:
Some ARM Cortex-M have a DWT (Data Watchpoint and Trace) unit implemented, and it has a nice feature in that unit which counts the execution cycles. The DWT is usually implemented on most Cortex-M3, M4 and M7 devices, including e.g. the NXP Kinetis or LPC devices.
During cold winters the Lake Lauerz gets covered with ice. And if it is cold enough for a few weeks it gets enough ice to have it completely covered more than 15 cm of ice. That’s the time of the year to enjoy a walk or to play ice hokey:
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:
When working and debugging a bootloader, debugging can be a challenge: During debugging the bootloader, a new binary gets loaded into the microcontroller address space which is unknown to the debugger. As soon as I step into the newly loaded binary, I only see assembly code, with that ugly “No source available” in Eclipse:
No Source Available, debugging in assembly
But wait: GDB is able to do pretty much everything you can imagine, so here is how to debug multiple binaries with GDB and Eclipse, and to turn the above into something which is easy to debug:
The Hexiwear docking station would have a nice feature: it has embedded a debug circuit (OpenSDA). That way I would not need an external debug probe to debug the Hexiwear. However, a debug probe is required to reprogram the docking station itself:
Repgrogramming the Mikroelektronika Docking Station
To me, one of the most frustrating things working with ARM Cortex-M cores are the hard fault exceptions. I have lost several hours this week debugging and tracking an instance of a hard fault on an ARM Cortex-M0+ device.
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 🙂
The Achilles Heel of the Mikroelektronika Hexiwear is its charging: the charging and USB connector are only designed for a limited number of plug-unplug cycles, and it does not have a wireless charging capability like the Apple iWatch. Until now! I have built a DIY wireless charging system for the Hexiwear 🙂 :