For a research project we would like to use the tinyK20 to log gyro sensor data. For this I have created a quick-n-dirty project to explore how feasible it is. The tinyK20 has all the pins on the outside of the board, so I’m able to put it on a bread board:
tinyK20 on Breadboard
The tinyK20 has been designed with the data logger as one of its applications. For this, there is a micro-SD card socket on the bottom side of the PCB:
Micro SD Card Socket on TinyK20
The cool thing with the tinyK20 is that I can use it to debug another board. As a bonus, the tinyK20 is able to power the target board trough the SWD cable:
:idea: The internal USB regulator of the Freescale Kinetis K20 is able to offer around 100 mA. I use the DC-DC converter on the backside of the tinyK20 to power more than the 100 mA.
tinyK20 debugging another tinyK20
I used a Segger J-Link to get performance data with the Segger SystemViewer.
Debugging with J-Link
Right now I’m logging dummy data. Checking the performance with the Segger SystemViewer for FreeRTOS shows around 20 ms to append 20 bytes to a file (csv format):
tinyK20 Data Logger with Segger SystemViewer
So far, I have plenty of power to do that data logger application, and I even have a shell with USB and the Segger RTT running. :-).
If you want to have a look at that data logger project, it is on GitHub: https://github.com/ErichStyger/mcuoneclipse/tree/master/Examples/KDS/tinyK20/tinyK20_DataLogger