Eclipse includes a background parser called ‘Indexer’ which is used to assist the developer with various kind of information, for example jumping to a variable declaration or definition. Basically it is a parser running in the background collecting information about the sources and building up that ‘index’ data base.
indexer debug output
The company Feller sells a wall mountable ‘Smart Light Control’: this provides 4 push buttons compatible with the Philips Hue system (on, off, dimming, etc). Unlike many other remote controls and buttons it is a great design and available in different colors. Feller does have a ‘classic’ wall switch series too, so this one is perfect to replace or augment an existing installation and make it ‘smart’.
Feller Smart Light Control
The Eclipse CODAN (Code Analysis) plugin is part of CDT and is a powerful static analysis tool finding all kind of possible bugs and issues. Still to my surprise not many C/C++ developers take advantage of it maybe because they are not aware that it exists?
ups! Programming error detected by CODAN
In this article I show a few tips how to effectively use it, especially with the NXP MCUXpresso SDK.
The NXP MCU-Link is a powerful $10 debug probe for ARM Cortex-M devices and works with the NXP LinkServer for debugging. The LinkServer does not an implement a gdb server, so it limits its usage e.g. for scripting or command line debugging. But as MCU-Link is also a CMSIS-DAP compatible debug probe, I can use it with OpenOCD which is open source and implements a GDB server. This article shows how I can use it with the MCU-Link.
Debugging FRDM-KL25Z with MCU-Link
The MCU-Link is a $10 CMSIS-DAP capable debug probe which works out-of-the box with the MCUXpresso Eclipse based IDE. This is great for development, but how can I programming with the push of a button or a script? The answer is no: there is an easy way to use the debug probe outside Eclipse from a shell script, and you can use that MCU-Link probe to do the job. This is especially useful as with the example below where I have to program 60 boards this week-end :-).
Batch Programming Boards with MCU-Link
A very useful feature in Eclipse is Ctrl+Shift+L which lists all the available shortcuts:
List of Shortcuts
Pressing Ctrl+Shift-L again will open up a dialog where I can configure them. But what if the shortcut or action is not listed there?
The NXP Kinetis devices implement a UID (Unique ID) for each device, using the ‘Unique Identification Register) which is part of the SIM (System Integration Module):
SIM Unique ID (NXP K22P144M120SF5RM.pdf Reference Manual)
While this number should be unique, I was wondering last week why students in the labs reported the same UID for multiple robots in the lab. So maybe this number is not so unique as it should be?
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Reentrancy is an attribute of a piece of code and basically means it can re-entered by another execution flow, for example by an interrupt or by another task or thread. This is an important concept and still a lot of code ‘in the wild’ does violate reentrancy. As a result the application crashes immediately in the best case. Worse it crashes randomly or even worse it behaves incorrectly 😦 .
Reentrancy is always a concern if using standard library functions, including printf() or malloc(). FreeRTOS offers a reentrant wrapper to the standard malloc() and free() (Memory Scheme 3)
Running FreeRTOS with reentrant newlib
If you are a regular reader of my articles, you probably know that I’m using FreeRTOS in most of my applications, for obvious reasons. But clearly this is not the only RTOS out there. After Microsoft had acquired Express Logic back in April 2019 things kept quite for a while. To me the crown jewel of Express Logic is the ThreadX RTOS. But recently Microsoft is pushing more and more the ‘Azure Sphere’ and trying to monetize the ‘IoT’ (I apologize for mentioning that overused acronym) application space and providing it now free for devices from selected partners which includes NXP now.
Debugging with ThreadX in MCUXpresso IDE
Philips Hue Smart LED stripes are great, but they have a disadvantage: the LED density is rather low: one LED cluster (WW, RGB, CW) every 55 mm. This leads to the problem that individual dots might be visible if the LED stripe is directly visible. Even if the LED stripe is used for indirect ambient light it means that individual dots might still be visible on the wall or ceiling. The solution is to create a ‘high density’ Hue smart LED stripe:
Normal vs High Density Philips Hue LED Stripe
