Hello,
I just received an NRF52DK today. I was able to run the demo (LED blink/Switch and NFC) which comes factory installed. But copying the hex files from demo (proximity, heart rate) fails. The flashing seems to happen as per the instructions, the JLink drive closes and reopens after flashing but the demo doesn't work as expected. I tried restting the board, turning off and then on, pressing all the switches and nothing seems to help.
For instance, in the proximity demo, the LED1 is not glowing as per the instruction. Pressing Switch 1 (short or long) doesn't help. I have tried this in a Mac, Linux/Ubuntu and Windows 10 machines but nothing helps. I also tried re-flashing with the default firmware (the one that has the NFC and LED/Switch demo) but fails too.
Here are some details of the board: Interface MCU version: PCA10040 V1.1.1 2016.38 682600795
Any help is much appreciated. Thanks.