DK52 Stopped working after connection with a different Mac

[fab]

Hi,

I got in trouble with my DK-52.

I normally use it attached to my iMac and everything work fine.

Since, I need to make some programming from another mac (macbook pro 15-inch, late 2016), I have installed:

- Segger Jlink
- Segger Embedded studio
- SDK 14.2.0

When I try to upload firmware to the DK-52 I get this message:

Failed to connect to target
No idcode detected.
Please check connection and Target Interface Type.

Unfortunately, now this happens with the old mac too.

Do I have dameged my board in some way?

How can I fix it?

[MartinBL]

Hi,

Can you please go through all the steps here: My nRF52/nRF51 DK kit doesn't work.

[fab]

Hi Martin,

Thank you for your help. Problem was quite different though.

I used the DK-52 to program a custom device. When I moved it from the old Mac to the laptop I removed the custom board but I left the jumpers wires connected to the P20 connector. This prevented to both Macs to recognize the DK52.

Which is the signal that makes the DK52 switch to the external device?

[MartinBL]

Hi,

The Segger MCU senses the voltage on the VTG pin. If it detects a voltage of ~3 V it assumes that an external device is attached. That is why you are supposed to connect Vdd on your external device to VTG.