Percepio has recently released the v2.7 version of Tracealyzer. This is a major upgrade from the v2.6 version which I have used so far: time to upgrade my Trace component for FreeRTOS to the latest and greatest v2.7!
FreeRTOS+Trace View (V2.7)
I have several applications where I store application specific information in the microcontroller FLASH memory (see “Configuration Data: Using the Internal FLASH instead of an external EEPROM“). I have run into issues recently with the Segger J-Link GDB server as by default it does *not* erase all the FLASH memory. So the question is: How can I erase all (or part) of the FLASH memory with GDB (e.g. in Kinetis Design Studio or in Eclipse)?
Memory Monitor with Erased Flash
The Freescale FRDM-K64F and FRDM-K22F have a different OpenSDA (v2) firmware on it: unlike the earlier (v1), that firmware is open and not protected which is a great thing. However, it has the disadvantage if you use the wrong SWD/JTAG header on your board, the bootloader on the K20 OpenSDA microcontroller is gone 😦
Two SWD Headers on FRDM-K64F Board
In my earlier post I used a hacked together shield for building a clock based on Adafruit’s NeoPixel/WS2812 (“LED Clock with Kitchen Hot Pan Protector“). The new design supports now 8 parallel data streams, integrated realtime clock and wireless connectivity with the nRF24L01+ module.
NeoPixel Shield for FRDM Boards
Freescale had announced at FTF back in April this year that they will use Kinetis Design Studio and the Kinetis SDK for all new Kinetis devices. The switch from CodeWarrior to Kinetis Design Studio (see “Comparing CodeWarrior with Kinetis Design Studio“) was not much of big deal for my projects (although CodeWarrior still has better features), and projects are rather easily portable. However, the move to the Kinetis SDK has been massively disruptive: Before it was easy to move projects from one device to another with Processor Expert, even from S08 to ColdFire to Kinetis. Now with the Kinetis SDK everything is very different. At least Freescale now officially supports FreeRTOS, and for myself as a big fan of that open source RTOS, that was some good news.
Blinking Red LED with FreeRTOS Task using Kinetis SDK, FreeRTOS and Processor Expert
So in this tutorial I’m showing how FreeRTOS can be used with the Kinetis Design Studio. That makes at least using the Kinetis SDK bit more familiar to me :-).
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.
Remote Communication Error, what now?
Newer microcontroller have increase RAM areas, making it suitable to run the application from RAM instead of FLASH. For the FRDM-K64F board and the Kinetis Design Studio (V1.1.1), I have explored how to run the application out of RAM instead of FLASH memory, both for P&E and Segger connections.
MK64FN1M0VLL12
How cool would it be to add WiFi support to any projects or IoT? Why not using WiFi with a microcontroller which has only few KBytes of RAM and FLASH. For less than US$5? Dreams came true, and intrigued by an article at Hack-A-Day, I searched a supplier for that ESP8266 module. And this evening I have found the four ESP8266 modules I have ordered for $4.50 each from ElectroDragon in my mailbox. Of course I did not want to wait for the week-end, so I hooked it up to my FRDM-KL25Z board.
ESP8266 Module for US$ 4.50
Found an interesting behaviour with the Freescale FXOS8700CQ on the new Sumo Robots (see “Sensor and Communication Shield for Sumo Robot“): when enabling the accelerometer/magnetometer, it actually did not work:
Failed to Enable FXOS8700 Accelerometer
Sometimes, there are ugly bugs in tools, and without knowing about them, it is likely to spend hours and hours, and of course to be frustrated. Knowing about these issues does not remove the issue, but at least helps to cut time to deal with it. And here is one which was nagging on me for a while with the GNU GDB debugger in Eclipse…..
💡 I have used the Q4 2014 GNU ARM Embedded (launchpad) toolsuite/gdb (4.9-2014-q4-major), and I have found that with that gdb version the issue described is fixed. If you are using Kinetis Design Studio, see “Switching ARM GNU Tool Chain and Libraries in Kinetis Design Studio” how to upgrade the tool chain.
I was happily debugging my project, making some changes, and suddenly I cannot debug it any more. What happens is that I can download the binary with GDB, but it immediately terminates and disconnects:
Terminating Gracefully Target Disconnected
After digging and doing some trial and errors, I have found what is causing this.
Initializing. Target has been RESET and is active. Disconnected from "127.0.0.1" via 127.0.0.1 Terminating Gracefully... Target Disconnected.
MCU on Eclipse 