After the proof of concept phase (see “Proof of Concept: Open Source ARM SWD Debug and General Purpose Board“), the first prototypes are ready:
I had the first prototypes of the board we have produced internally in my hands:
A different USB connector can be populated on the backside of the board, so it can directly be plugged into a USB port. Additionally the board can be placed into a small USB thumb drive case that way (I don’t have one for a picture now, but we use them for a different project).
Here it is one tinyK20 debugging the FRDM-KL25Z board:
One tinyK20 debugging another tinyK20:
Not the first time it happens to me :-(: things always look better on the layout 😉
Fort the next iteration, a few changes are under consideration:
- Must have: The reset button needs to move away from the target MCU SWD connector.
- Optional: Changing orientation of the ‘plugin’ version: if I plug-in the board into a notebook, the board components are not visible.
- Optional: Potentially move the target MCU connector so it does not block the pin rows.
- Optional: Using a smaller clock (Murata Electronics CSTCE8M00G55-R0). The latest FRDM boards are using this one too (FRDM-K64F, FRDM-K22F) for the K20, so it seems this one is accurate enough for USB operations. That would save space.
- Optional: make the capacitors around the K20 clock DNP (Do Not Populate) to reduce part number.
Let me know what you think, Do you have other ideas? Or anyone has a better name than ‘tinyK20’?
Happy Debugging 🙂
- Proof of Concept: Open Source ARM SWD Debug and General Purpose Board
- OpenSDAv2 article and link to bootloader: https://community.freescale.com/docs/DOC-100720