In the age of high-resolution graphical LCDs using a character display might look like a bit anachronistic. But these displays provide a lot of value for me as they are robust, available in different shapes and number of lines. And such a character display can be a better solution for an industrial application.
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:
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 …
I’m pleased to announce that a new release of the McuOnEclipse components is available in SourceForge, with the following changes and updates:
- SEGGER SystemView updated to V2.42
- More components to work with MCUXpresso SDK: GenericSWSPI, FXO8500 and SimpleEvents
- SSD1351 display driver supports 128×128 pixel resolution and Adafruit 1.5″ breakout module
- Extended FreeRTOS debug helper settings
- GenericI2C: added ReadWordAddress8() and ReadWordAddress8() functions
- RingBuffer with new Getn() and Update() functions
- Utility with map(), constrain(), random() and randomSetSeed()
- XFormat: new xsnprintf(), contributed by Engin Lee
- OneWire protocol component with Maxim DS18B20 temperature sensor
- Many smaller bug fixes and enhancements
I believe in ‘life-long-learning’. With this I continue to learn and discover new things every day. I’m writing tutorials to give something back to the community from which I have learned so much.
On top of this, I receive emails on a nearly daily basis, asking for help. Many articles have the origin in such requests or questions. I prefer questions or comments in a public forum, because that way I feel all others can benefit from it. Last week Alessandro contacted me with this:
I hope this find you well! I’m starting to using ARM processors, but I find them quite complicated on the configuration side. I started in the past with PIC micro (PIC16) with asm, and I found them quite straightforward to be configured (clock, IO, peripherals, …). Then I moved myself on C language, and on PIC18 without any big issues.
Now I would really like join the ARM community, I see that these processors are what I’ve always looking for, on energy, calc power, peripherals, and FINALLY on IDE (editor, toolchain and utilities)… AMAZING!!!”
The topic is about how to start learning developing for ARM. Alessandro agreed to make this public, so I thought this might be a good topic for an article?
Time is passing by so fast, and the year end is approache fast! I’m pleased to announce that a new release of the McuOnEclipse components is available in SourceForge:
- Percepio Trace V3.1 for FreeRTOS which includes both Segger RTT continuous streaming and snapshot tracing in a single API
- Generation of sources and drivers so they can be used without Processor Expert using McuLibConfig, removal of dependency to NXP Kinetis SDK: components use a generic API approach to have them working with other SDKs.
- New contributed ExceptionsHandler component
- Callback Setter and Getter in USB CDC stack for simpler option handling
- GenericTimeDate with flexible RTC support and added Unix Timestamp functions
- LongKey events in Key component
- FreeRTOS with optimized task selection on Cortex-M4/M7
- Many smaller bug fixes and enhancements
A new McuOnEclipse components release was long overdue, so I’m pleased to announce that a new drop is available with the following major changes:
- Segger SystemView library with kernel time reporting
- GenericTimeDate supports different hardware RTC devices
- Utility with little endian packet handling functions
- Shell Standard I/O handlers for USB CDC, Segger RTT and Bluetooth
- FreeRTOS and stack size reporting
- printf() support in Shell component
- Various small bug fixes and improvements
Time for a new major update of the McuOnEclipse components, with the fillowing main features and changes:
- FatFS component updated to R0.12 with patch 3 and exFAT support
- Extended support for Cortex-M7
- Extended support for Kinetis SDK V2.0
- USB component support for Kinetis SDK V1.3
- Improved FreeRTOS for NXP FreeRTOS TAD plugin
- Added C++ wrappers to multiple components
- Many smaller fixes and improvements
A new release is available on SourceForge, with the following main changes:
- Support for FreeRTOS and Cortex-M7
- Segger SystemView updated to V2.38
- Components for NXP Kinetis SDK V1.3
- Fixed bug in Wait component (register handling for GCC and ARM)
- FatFS supports FreeRTOS V9.0.0 with static memory allocation
- FreeRTOS shell and task list with static memory allocation
- Floating point conversion routines in Utility
- FreeRTOS component shows NVIC mask bits
With the start of the new year 2016 I have published a new McuOnEclipse component release with the following major updates:
- Updated Segger SystemView and Real Time Transfer (RTT): added terminal functions and extra interfaces
- Improved USB CDC with serial number handing
- FreeRTOS TaskList shell command
- USB Stack: added MSD Host support for MCF52259, added support for K24FN120 and for the 100 MHz K20 devices
- New NEOMatrix component for Adafruit NeoPixel Matrix displays
There are cases when I need to do a reset of the device by software. For example I have loaded the application image with the bootloader, and then I need to perform a reset of the microcontroller to do a restart. As a human user I can press the reset button on the board. But how to do this from the software and application running on the board, without user manual intervention? Or if I simply want to reset the system for whatever reason?
I think the biggest frustration point for any new or even seasoned engineer is the debugging phase: my application finally builds fine, but I’m not able to connect and download it to the target board :-(. In my view the debugging part is the most fragile part of the development process. I’m always very relieved if I can connect to a brand new board, because I know if it does not work, then the problem could be a very bad one, costing my several hours or even days to overcome it.
While new Freescale boards come with the OpenSDA debug firmware, I still students using boards with the OSBDM/OSJTAG. And with new CodeWarrior tools, it might be that there is a new OSBDM/OSJTAG firmware, and when I download to a board with an older firmware, the tool will prompt me to update the firmware. To me, after doing this several times, not a big deal. But for someone who sees this the first time, it might not be that easy. So to avoid any further questions, here we go with a step-by-step tutorial how to update the OSBDM/OSJTAG firmware.
The final FreeRTOS V8.0.0 has been released last week: time to update the Processor Expert component for it, and this time it is really a major release 🙂 : from V7.5.0 to V8.0.0:
FreeRTOS V8.0.0 comes with many small changes, especially it now includes many of the extra casts I have contributed to avoid compiler warnings. And additionally it has a brand new feature: Event Groups.
I admit: I have used ARM Cortex cores a lot in the recent months. Yes, I think with the ‘ARM domination of the world’ over time the ARM core will blast away probably all other cores, except for niche players? Still, there are reasons to use non-ARM cores, and even if it is just that I have a board at hand :-).