NRF52-DK MBED support problem!

Dear team,

I bought a nRF52 DK which is labled "PCA10040 V1.2.1 2017.21 xxxxxxxxx". xxxxxxxxx is a serial number, I guess. I just could not run the most simple example of mbed-os-example-blinky. This board defaultly supports Jlink OB so I follow instructions in mbed website to update the inferface firmware. The link is "

What I did are:

1,make the PCA10040 go into bootloader mode by resetting it while holding the BOOT/RESET botton.

2, drag and drop the latest inferface firmware "Version 0219." onto bootloader disk then reset the board. I noticed that this latest firmware is coming from nordic and it is named" nrf51822aa_atsam3u2c_if_mbed_V0219_02022016.bin". But my board is soldered with a nrf52832. Is this ok?

3,drag and drop "mbed-os-example-blinky_NRF52_DK.hex" onto MBED disk and then resetting the board. And nothing happens. I could not see the led toggling... Actually some error happens because I saw a file named "fail.txt" with contents "TIMEOUT" appear onto the MBED disk. The " mbed-os-example-blinky_NRF52_DK.hex" is what I got using MEB online complier with NRF52 DK selected as my target baord.

By the way, I am using windows 10.

Can anyone help ? Could you check to see if you could reproduce this issue by following my steps?

  • Not sure why you need to update the MBED interface firmware at all as the PCA10040 should work as is. Have you tried to use nRFgo studio to load the blinky example into the nRF52?

  • Thank you Matt! It works when I drag and drop the blink example into PCA10040 after I restored PCA10040 back to Jlink OB. You are right. PCA10040 originally supports mbed. It does not need to get interface firmware programmed at all....

    Actually the user guide of PCA10040 and mbed's link to this board both mention how to swap between Jlink OB and mbed interface..... This made me think I need to update interface firmware. But it is not necessary at all.

    Hope other guys would not make such silly mistake again.

    Thank Matt again!