The tinyK22 board is a tiny micro controller board we use at the Lucerne University of Applied Sciences and Arts. It is used in many research project, used in lectures and labs and used in most student projects. Because there was no small and breadboard friendly NXP Kinetis board with a debug interface available, we developed one featuring the NXP K22FN512, named the ‘tinyK22‘. Because of the success and high demand we stated a new large production run and used this to upgrade the board to the new Rev 1.3: you might notice already the color change :-).
The board is a breadboard-friendly, inexpensive and universal ARM Cortex-M4F which can be easily used for a broad range of projects. The board incorporates the OpenSDA circuit and is basically a stripped down version of the popular NXP FRDM-K22F board.
The board works with GNU Tools for ARM Embedded and can be used out-of-the-box with the NXP MCUXpresso IDE and SDK, or any other custom IDE or tool chain for the K22F512.
Beside of the PCB color change from green to blue, there are several updates with the new V1.3 revision:
First, the SD card holder on the back plus the DC-DC converter for power-hungry cards is populated by default:
To program and debug the K22, the OpenSDA K20 circuit on the board is used. To save costs and PCB space, both the K20 (debug interface) and the MCU (K22) can be directly programmed with a Tag Connect cable:
That special debug adapter is from Tag-Connect and the one for ARM Cortex processors. The ‘retaining’ clip is recommended too:
With the previous revision, if a student accidentally programmed the K22 with a bad program causing the target to constantly reset, then the OpenSDA circuit was not able to access the CPU (see Adding a Delay to the ARM DAPLink Bootloader on a similar subject). What could happen is that the K20 is forced into bootloader mode. To solve the problem the diode D5 has been added to the reset line:
So far the board has been used in-house for research and education. We received frequent requests if we could sell that board. Because we now manufacture and assembly the boards at PCBWay, we published the design and manufacturing files. That way everyone can order boards from there too. The design is available on https://www.pcbway.com/project/shareproject/TinyK22_V1_3.html
So the new Rev 1.3 boards are produced by PCBWay for us, and you can order yours from there too. Additional information can be found in the links below.
Happy tiny’ing 🙂
Update: the tinyK22 is now featured on Hackster.io: https://www.hackster.io/news/lucerne-university-of-applied-sciences-and-arts-launches-tinyk22-educational-dev-board-v1-3-7be7cebb9d34
- tinyK22 Boards arrived (Rev A)
- First tinyK22 Board with NXP K22FN512 ARM Cortex-M4F
- Documentation and Files on GitHub: https://github.com/ErichStyger/mcuoneclipse/tree/master/tinyK22
- Shared Design on PCBWay: https://www.pcbway.com/project/shareproject/TinyK22_V1_3.html