It has been a while since my first post about the ESP8266 (see “Cheap and Simple WiFi with ESP8266 for the FRDM Board“). The ESP8266 is a new inexpensive ($4.50) WiFi module which makes it easy to connect to the network or internet. Finally this week-end I have found the time to write up a tutorial:
how to implement a WiFi web server for the ESP8266 WiFi module and the Freescale FRDM-KL25Z board:
Category Archives: CPU’s
Tutorial: Playing MP3 Files with VS1053B and FRDM Board
I want to make some noise with this post!!! This tutorial is about adding music and sound capabilities to the Freescale Freedom board, and to have a lot of fun with it :-). I need this ability for a larger project working on for a while. But I thought I share that sub-part how to play sound files. So with this tutorial I can turn my Freescale Freedom board into a music or sound player :-). And adding sounds is a cool way for any project, and as the music is stored on an SD card it fits easily hours of music or sounds.
Tutorial: How to Erase the FLASH with the GNU GDB debugger
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)?
Adding Processor Expert to Atollic TrueSTUDIO
For me as an Eclipse and Processor Expert lover, a press release that Atollic supports Processor Expert catched my eye :-). So there is yet another way to use Processor Expert: with a commercial Eclipse IDE provided by Atollic (atollic.com/).
Time to check it out…
Recovering the FRDM-K64F Bootloader, or: Cloning the Program of a Microcontroller
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 😦
NeoShield: WS2812 RGB LED Shield with DMA and nRF24L01+
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.
Using Keil μVision 5 with Processor Expert
I happily used the Keil v4.71.2.0 μVision tools for a few small projects (see “Using Keil µVision (ARM-MDK) with Processor Expert Driver Suite“) with the ‘lite’ edition (32kByte code size limitation). This weekend I wanted to move to the new v5.12.05 version.
And there were indeed several things which are different. So this is post is about getting this version getting up and running as the v4.7 one.
Tutorial: FreeRTOS with the Kinetis SDK and Processor Expert
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.
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 :-).
Debugging Failure: Check List and Hints
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.
RAM Target with Kinetis Design Studio and FRDM-K64F
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.









