nrf51 smart beacon kit jtag programming

RE: nrf51 smart beacon kit jtag programming

Stian Røed Hafskjold — Thu, 10 Sep 2015 12:55:32 GMT

I've never experienced anything like that, so I'm not really sure what is going on. The reset pin is not really needed since the device is reset through the SWDIO pin. Actually on the nRF51 chip nRESET and SWDIO is the same pin, so in order to reset, the J-Link goes out of debug mode and then pulls the SWDIO pin low. Are you sure you bought a genuine Segger? It is a lot of copies out there.

You can try to download the latest drivers for your J-Link, www.segger.com/jlink-software.html, and then flash it with the newest firmware (Using J-Link Configurator).

You also mentioned that you had a pull up on the SWDIO, you can try to remove this as it is not really needed. There is an internal pull up on the chip.

Other than that, the only thing I can think of is HW issues. If it turns out it is the HW on the beacon, you can open up a case in the support portal and get a replacement.

RE: nrf51 smart beacon kit jtag programming

Mike — Thu, 10 Sep 2015 10:37:46 GMT

so now, I can reprogram the device no problem, just the steps seem rather odd. I suspect maybe it is something to do with with reset pins? referring to this datasheet for the TC2030 connector, it seems pin 3 could be used as nRESET, which is missing from my wiring

RE: nrf51 smart beacon kit jtag programming

Mike — Thu, 10 Sep 2015 10:33:57 GMT

I have did some further testing and managed to program it, but in an rather odd way.

To erase in nrfgo studio,

connect jtag to device while battery is out
put in battery and click refresh (now nrfstudio would show the device)
take battery battery and put it back again
click erase and wait for nrfgo studio
the device is now erase so basically whenever I need to do some operation in nrfgo studio, I have to take the battery out between each click, so if I wanted to program the softdevice, I would do that in step 4

now to program in keil, using the jtag interface, (not through nrfjprog), this gets even more interesting

connect jtag to device while battery is out
put in battery and click program
wait for program to finish and it is done for any subsequent programming, I don't need to take the battery out anymore, until if I hit the refresh button in nrfgo studio

RE: nrf51 smart beacon kit jtag programming

Stian Røed Hafskjold — Thu, 10 Sep 2015 08:24:38 GMT

In the nRF Tools package there is a program called nrfutil.exe. (Should be placed in "C:\Program Files (x86)\Nordic Semiconductor\nrf51\bin") You can try to open that in cmd and write 'nrfjprog --recover'. Also try the 'nrfjprog --erase'.

RE: nrf51 smart beacon kit jtag programming

Mike — Thu, 10 Sep 2015 00:18:07 GMT

Yes, I'm using pin 1,2,4,5. As for the connection, I just soldered wires directly to the pad, and directly into the 20in connector on JTAG programmer. Pull up for SWDIO, no pull for SWCLK.

I cannot erase the chip unfortunately, after it is detected the first time, any button I press: refresh, erase, read etc... Will result in device not found.

RE: nrf51 smart beacon kit jtag programming

Stian Røed Hafskjold — Wed, 09 Sep 2015 14:43:36 GMT

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.

RE: nrf51 smart beacon kit jtag programming

Mike — Wed, 09 Sep 2015 12:21:16 GMT

it's a segger j-link education version. I have measured the voltage and it is 2.9V at the moment with the current battery, would that be a problem? (also I noticed that most of the button cell batteries I have are 3V, so how do I achieve 3.3V or more?)

but if the problem is with the battery, why does it work the first time if I plug in the JTAG first before the putting in the battery?

update: I have just tried to power it from the 3V3 of an arduino, exactly the same behaviour, it is only detected once if I plug in JTAG before powering it

RE: nrf51 smart beacon kit jtag programming

Stian Røed Hafskjold — Wed, 09 Sep 2015 11:44:45 GMT

Which J-Link programmer do you have? Maybe your battery has too low voltage. The J-Link Lite requires 3.3V to be able to flash. Try to connect a power supply to it instead (Or a fresh battery)