nrf51 smart beacon kit jtag programming

[Mike]

Hi,

I have just received my smart beacon kit (nRF51822 based), I have wired up my JLink programmer according to devzone.nordicsemi.com/.../

However I am having trouble detecting the beacon kit on nRFgo Studio. nRFgo studio keeps saying that no device detected.

Normally, after inserting the battery, the beacon's LED will start flashing. If I plug in the programmer afterwards, nRFgo studio doesn't detect the device.

After a few tries, I managed to find 1 particular condition that allows the nRFgo studio to detect the device, which is connecting the JTAG programmer first, and then put the battery in. Now the LED doesnt turn on at all. When I click the refresh button for the first time on nRFgo studio, the device is detected, with the correct IDs, SD version etc. Then the LED would start flashing. However, if I click the refresh button again, the device is no longer detected.

I suspect that once the device is booted and the application is running, it somehow cuts out the JTAG interface.

Could anyone share some light in this issue? Cheers.

Warm regards, Mike

[Stian Røed Hafskjold]

I'm not sure why it behaves like that, it is a bit strange. I assume that you have doubled checked the connection between the beacon and the debugger. Only SWDIO, SWCLK and VTref should be connected (pin 1, 2 and 4) (And GND of course). Are you using an adapter from the J-Link, to get the 10 pin mini header, or are you connecting the 3 wires directly on to the 20 pin header on the J-Link?

Are you able to erase the chip from nRFgo Studio when it connects the first time? Maybe the chip goes in to power off mode when the code starts to run.