When using an RTOS like FreeRTOS, sooner or later you have to ask the question: how much time is spent in each task? The Eclipse based MCUXpresso IDE has a nice view showing exactly this kind of information:
FreeRTOS Runtime Information
For FreeRTOS (or that Task List view) to show that very useful information, the developer has to provide a helping hand so the RTOS can collect this information. This article shows how this can be done on an ARM Cortex-M.
Human since 1982 claims
“Human since 1982 have the copyright to works displaying digital time using a grid arrangement of analog clocks…”
I’m not a lawyer, but without obligations (imho) I have removed the content.
Thanks for understanding,
Erich
OpenPnP (see “Building a DIY SMT Pick&Place Machine with OpenPnP and Smoothieboard (NXP LPC1769)“) is a cool open source framework to run Pick&Place machines. I have mentored and supported Tobias Mailänder who extended the PnP machine with the ability to dispense solder past on PCBs. Below a video (courtesy of Tobias Mailänder) which shows the machine in action:
It is still a prototype, but things are working very well.
I really love clocks. I think this is I am living here in Switzerland. Beside of that: clock projects are just fun :-). After I have completed a single clock using stepper motors (see “DIY Stepper Motor Clock with NXP LPC845-BRK“), I wanted to build a special one which is able to show up to four different time zones: Below an example with London (UK), New York (USA), Beijing (China) and Lucerne (Switzerland):
Stepper Clock
The NXP LPC55S69-EVK is a versatile board. In this article I show how it can be used with Adafruit TFT LCD boards, both with resistive and capacitive touch. For the software I’m using the open source LittlevGL GUI.
LPC55S69-EVK with Adafruit Touch LCD
When Espressif released in 2014 their first WiFi ESP8266 transceiver, they took over at least the hobby market with their inexpensive wireless devices. Yet again, the successor ESP32 device is used in many projects. Rightfully there are many other industrial Wi-Fi solutions, but Espressif opened up the door for Wi-Fi in many low cost projects. Many projects use the ESP devices in an Arduino environment which basically means decent debugging except using printf() style which is … hmmm … better than nothing.
What is maybe not known to many ESP32 users: there *is* actually a way to use JTAG with the ESP32 devices :-). It requires some extra tools and setup, but with I have a decent Eclipse based way to debug the code. And this is what this article is about: how to use a SEGGER J-Link with Eclipse and OpenOCD for JTAG debugging the ESP32.
Robot with ESP32 and JTAG Debug Port
The Espressif ESP32 devices are getting everywhere: they are inexpensive, readily available and Espressif IDF environment and build system actually is pretty good and working well for me including Eclipse (see “Building and Flashing ESP32 Applications with Eclipse“). The default way to program an ESP32 is to a) enter UART bootloader by pressing some push buttons and b) flash the application with ESP-IDF using a USB cable.
That works fine if the ESP32 is directly connected to the host PC. But in my case it is is behind an NXP Kinetis K22FX512 ARM Cortex-M4F microcontroller and not directly accessible by the host PC. So I had to find a way how to allow boot loading the ESP32 through the ARM Cortex-M which is the topic of this article.
TTGO ESP32 MICRO-D4 Module
This project is about building a stepper motor clock around the NXP LPC845-BRK board. The design is using a combination of 3D printed and laser cut parts and costs below $15.
Stepper Clock Acrylic Face White Hands
A few days ago NXP has released a new version of their Eclipse IDE flagship: the MCUXpresso IDE v11.0.
NXP MCUXpresso IDE V11.0.0
The previous v10.3.1 was released back in Feb 2019, and the 11.0 now in June this year matches up with the Fall university semester. I appreciate that the releases are about every 6 months, so this gives me time to use it in my university lecture material and lab work. I had the weekend for trying it out, and I’m very pleased.
There are different ways to ruin a Linux system. For the Raspberry Pi which uses a micro SD card as the storage device by default, it comes with two challenges:
For problem one I do I have a mitigation strategy (see “Log2Ram: Extending SD Card Lifetime for Raspberry Pi LoRaWAN Gateway“). Problem two can occur by user error (“you shall not turn it off without a sudo poweroff!”) or with the event of a power outage or black out. So for that problem I wanted to build a UPS for the Raspberry Pi.
Raspberry Pi with UPS System and tinyK22
In “Tutorial: MCUXpresso SDK with Linux, Part 1: Installation and Build with Maked” I used cmake and make to build the SDK application. In this part I’m going to use the command line gdb to debug the application on the board.
Cross-Debugging with GDB
In “Debugging the RV32M1-VEGA RISC-V with Eclipse and MCUXpresso IDE” I described how to build and debug applications for the VEGA RISC-V board. In this article I describe how to enable FreeRTOS for RISC-V, based on the latest FreeRTOS V10.2.0 release.
Blinky with FreeRTOS on the VEGA RISC-V Board
Most host or desktop systems (say Linux, Mac or Windows) have a normal use case where you start the operating system say in the morning and shut it down in the evening, and then you leave the machine. Embedded Systems are different: they are not attended, and they are supposed to run ‘forever’. Not every embedded system needs to run an OS (or in that world: Real-Time Operating System or RTOS), but the same applies here: after the RTOS is started, it is not intended that it will shutdown and restart. To the extend that you won’t they support the ‘shutdown’ and ‘restart’ functionality at all. In case of gathering coverage information this would be really useful:
coverage information from FreeRTOS application
In the case of FreeRTOS: what if I really need to shutdown the RTOS and restart it again, as by default this is not supported. This is what this article is about …
GDB supports a mode which allows the GDB debug client to read memory while the target is running. This allows features like ‘live variables’: that way I can see the variables refreshed and changing over time without halting the target. Another functionality which comes with that feature is to check stopped threads or to see all threads in the system.
multiple FreeRTOS threads in debug view
Working with low power modes can be challenging. It can severely affect debugging capabilities of a microprocessor or microcontroller. I ported a FreeRTOS application using the Tickless Idle Mode to the NXP i.MX RT1064 board, and all of a sudden, the board was unresponsive to any debugger connection. Luckily the board was not really bricked, but it took me while to find a way to recover it. So for when you end up in a situation with a ‘bricked’ i.MX RT1064 board, this article might be helpful for you to recover it.
i.MX RT1064-EVK Board
Friday this week NXP has released a new version of their flagship IDE: the MCUXpresso IDE V10.3.0. The version number indicates an incremental update from the earlier V10.2.1, but there are many exciting features and new features which make me switch my lecture material to this new IDE for the next semester.
MCUXpresso IDE V10.3.0
You might wonder what ‘Zork‘ is? Zork is one of the first and earlist fictive computer games, written around 1977 and 1979, written in MDL on a DEC PDP-10 by members of the MIT Dynamic Modelling group (see https://en.wikipedia.org/wiki/Zork). I believe the first time I have played Zork was around 1984 on a Commodore 64.
Zork
I’m pleased to announce a new release of the McuOnEclipse components, available on SourceForge. This release includes several bug fixes, extra support for the NXP S32 Design Studio and SDK and includes FreeRTOS V10.1.1.
SourceForge
Most embedded projects need an user input device. For the NXP i.MX RT1050-EVK board I have recently added a 480×272 full color touch LCD (see “Adding a Rocktech Capacitive Touch LCD to the NXP i.MX RT1052 EVK“). I have looked at different commercially available GUI libraries, but none of them really were matching my expectations: either very expensive or closed source, or an overkill for small LCDs and projects. But then I have found LittlevGL: free-of-charge, open source, easy to use, well documented and has everything I need. And it really looks gorgeous 🙂
Hello from LittlevGL
FreeRTOS includes a nice feature to give me information about how much time every task is spending running on the system:
FreeRTOS Runtime Information
This tutorial explains that FreeRTOS Runtime Statistics feature and how it can be turned on and used.
