Any ideas what might be wrong with my MB-N2 based design?


Howdy. I’ve completed my first custom PCB design using kicad. It’s a simple device based around the MB-N2 with a couple push-buttons. After reading the documentation I removed as much optional circuitry as possible. You can see my other post here.

After soldering everything and connecting SWDIO and SWDCLK to my DAPlink v1.0, unfortunately it fails to flash. I’ve confirmed that flashing the same program on the Nano 2 works fine. I also used a multimeter to double check all my soldering and PCB connections.

I have a feeling I might have missed something obvious that I’m just not seeing. I’ve included an image of my simple circuit. Any ideas what might be wrong?



Hi @anders,

Besides the SWDIO and SWCLK, have you also connected the VDD and GND to DAPLink? Can you attach a picture to show how you wire your dev board and the DAPLink?

Best regards,


Hi @guohui,

I am connecting SWCLK and SWDIO and pins 38 and 39, respectively. Those are the only connections from my board to the DAPLink. I figured the DAPLink has its own VDD and GND since it’s plugged into my computer and the PCB has its own battery. Do they need to share the same VDD/GND? I could see how that might make sense depending on how the signalling is done.



If your board has independent power supply, you just need to connect the GND between each moreover, such that they have the same reference ground to make sure the communication is reliable.


ok I’ll try that and report back