nRF52832 flashing custom board

RE: nRF52832 flashing custom board

Mohsen_K — Fri, 16 Jul 2021 21:08:44 GMT

I had the same exact problem. I found why that happens and I think it is a design flaw of the programmer! The only thing you need to do is to exchange the sides of the cable connecting board to the programmer! Although connectors on both sides are identical it matters which side of the cable goes where!

RE: nRF52832 flashing custom board

Vala — Mon, 05 Sep 2016 09:16:39 GMT

Hi,

The problem was that the RESET pin of the chip was pull down in my circuit since I had considered it as an IO. In this mode the CPU does not respond to programmer either. I tested the same thing with nrf52DK. I connected the P0.21 of the nRF52832 to GND, then turned on the board and the CPU did not start working.

I will ask about the RESET pin functionality in another question.

-Vala

RE: nRF52832 flashing custom board

Vala — Fri, 02 Sep 2016 11:11:12 GMT

Yes, I am able to program the nRF52DK by the jLink EDU that I have.I have also used it for other SoCs/MCUs. But I have never used it with 1.8V.

There is one strange thing happening with my jLink though. When I connect it to Debug out of the nRF52DK and disconnect the power from the nRF52DK the LED on the programmer turns orange for a little while (which is guess says that the target doesn't have power) and then it turns green again.

When I repeat exactly the same process with my custom board (which has the 1.8V power source) the LED never turns orange and it stays green.

This seems to be a problem.

RE: nRF52832 flashing custom board

Vala — Fri, 02 Sep 2016 11:06:07 GMT

Appreciate your follow-up Roger. Yes, there is 3.3 LDO on the board but there is a diode after that (for reverse voltage protection) which drops the voltage to 2.87 (what my multimeter shows). As expected, the output from the LDO is 3.3V and the output of the diod is 2.87V on my nRF52DK.

RE: nRF52832 flashing custom board

Roger Clark — Fri, 02 Sep 2016 11:01:21 GMT

Could be the Jlink is faulty, Do you have any other SWD debuggers, e.g. STLink, or CMSIS DAP or BlackMagic probe. (Or do you have any other hardware that you could program to be any of the above.

Or can you borrow another SWD programmer ?

I have 2 JLink's I bought from eBay, 2 STLinks, 1 CMSIS DAP and several boards flashed with Blackmagic probe ;-) (but I guess I'm unusual)

RE: nRF52832 flashing custom board

Vala — Fri, 02 Sep 2016 10:49:11 GMT

And I checked some other things:

1- I checked the DEC outputs of the MCU to make sure that the power is in present for the MCU. I get all the expected values e.g. 0.9V and 1.3V. I also have DCC connected to DEC4 through two inductors.

2- I checked if the SWDIO and SWDCLK pins have the pull-up and -down voltages. They are also OK.

So I guess I have all the voltages and connections fine. Now I have only the last option, which is changing the chip, right?

RE: nRF52832 flashing custom board

Roger Clark — Fri, 02 Sep 2016 10:47:11 GMT

Do you know why you only have 2.82V ? I don't have the nRF52DK I only have various nRF51822 boards, and they all have 3.3V supplies mainly via regulators from 5V USB

But I don't know whether 2.8V is normal for the nRF52DK. You may be able to get a schematic for that DK and check if its supposed to only be 2.8V though it seems a strange voltage to use

RE: nRF52832 flashing custom board

Vala — Fri, 02 Sep 2016 10:42:59 GMT

And one update:

In my first post I said that I was not able to program the nRF52DK without RESET pin connected to the programmer. It was wrong. I have no idea why. I tried it again and everything works perfectly with nRF52DK using Debug Out connector and without RESET pin used.

RE: nRF52832 flashing custom board

Vala — Fri, 02 Sep 2016 10:41:30 GMT

I powered up the MCU with 2.8V got from nRF52DK. jFlash reports the same:

Connecting ...

Connecting via USB to J-Link device 0
Target interface speed: 200 kHz (Auto)
VTarget = 2.832V
ERROR: Failed to connect. Could not establish a connection to target.

When I use 1.8V generated in my own board I get this:

Connecting ...

Connecting via USB to J-Link device 0
Target interface speed: 200 kHz (Auto)
VTarget = 1.793V
ERROR: Failed to connect. Could not establish a connection to target.

nrfjprog although gives a different report:

λ nrfjprog --clockspeed 1000 --family nrf52 --recover Recovering device. This operation might take 30s. ERROR: JLinkARM DLL reported an error. Try again. If error condition ERROR: persists, run the same command again with argument --log, contact Nordic ERROR: Semiconductor and provide the generated log.log file to them.

I'm not sure why it gives a DLL error. Because I am able to program the nrf52DK with same command and the same programmer (using Debug In connector).

Also here some one was able to program the MCU with 1.7V. The minimum voltage for jLink is 1.2V.

RE: nRF52832 flashing custom board

Roger Clark — Fri, 02 Sep 2016 07:26:49 GMT

Can you connect VREF to another supply of 3.3V then see what voltage Jflash reports.

It doesnt need to be connected to the actual board you are programming

If your Jlink has a 3.3V output, (some do) just connect it to that voltage

RE: nRF52832 flashing custom board

Vala — Fri, 02 Sep 2016 07:17:14 GMT

Thanks for your comment Roger. By VREF in my post I meant VCC. So I have this pin connected. I cannot use jFlash for erasing or programming the MCU since I don't have its license (I'm using jLink EDU). I can only use the option 'connect' in jFlash. When I try to connect it (after choosing the right device in jFlash of course), it detects the voltage level correctly (about 1.8V) but gives me this error: ERROR: Failed to connect. The jLink datasheet says that the minimum voltage is 1.2V. So there shouldn't be a problem with 1.8V. Additionally, I have tried feeding a 3V voltage to VCC sense pin of the programmer (which is not a good practice since the voltage level of the SWDIO and SWCLK is set according to VCC sense) but still getting the same error.

RE: nRF52832 flashing custom board

Roger Clark — Thu, 01 Sep 2016 23:33:52 GMT

I am not sure about the nRF52832 but the nRF51822 and all other ARM based devices I have worked with, only require 3 SWD pins GND SWCLK and SWDIO

With JLink you also need to provide Vcc to its Vcc sense pin, otherwise it doesn't think your board is powered up.

So connect 3.3V to the Voltage sense pin

I use both JLink and also the BlackMagic probe and I never have to connect reset (I don't even know if Blackmagic probe has a reset pin - but it may do)

Just try using JFlash, and select the correct template for the device. Make sure you have SWDIO and SWCLK around the right way