nRF9160 DK stopped responding to AT commands

[stevenminnick]

I have 2 nRF9160 DK's.  I've been using 1 for most of my testing and the second one was still in the box. 

I loaded the secure boot and the AT_CLIENT demo project.  Opened up the nRF Link Monitor tool.  Hit the reset button and Zephyr stuff flies on the screen.  Ends up with:

Secure Boot: prepare to jump to Non-Secure image

***** Booting Zephyr OS v1.13.99-ncs2 *****

The AT host sample started.  err=0

(I added the err=%d) in the printf statement to prove that I was doing stuff. 

The problem is when I send it an AT command, I get: Error: 'AT ' timed out

I reloaded the modem firmware with: nrf9160_mdm_dfu --update 

That worked.  But still did not respond to AT commands, just time out.

Took my other dev kit out of the box.  Moved my sim card to DevKit #2.  Loaded the same code on it.  With this: nrfjprog.exe --program zephyr.hex --sectorerase -r -f nrf91 --verify

Reboot DevKit #2, and get the same Zephyr messages and everything works.  AT commands work.  Connects to the network. 

Hook back up to DevKit #1, AT commands time out. 

Now I did solder on a 1 ohm resistor on R60 to measure current.  And if I program the asset tracker software to it, it connects and works perfectly.  But why does the AT_CLIENT time out now? 

Anyone have any thoughts?  Thanks!

Steve

[stevenminnick]

Basically I have 2 dev kits.  The asset tracker application works on both of them.  But the at_client software only works on 1 of them. 

The 1 where the at_client doesn't work I was trying to use the IDE to debug, trying to step through.  But I ended up just using the programmer and erasing the whole memory and cloning the second dev kit and the at_client still doesn't work. AT commands just time out.  But it works perfectly on the second dev kit. 

[Bjørn Kvaale]

Have you tried to reset the board multiple times by pressing the RESET button. Erase the flash via nrfjprog --eraseall -f nrf91, then program the secure_boot example via Segger Embedded Studio & finally program the at_client example. Then, open up the Link Monitor application from nRF Connect for Desktop & connect to the board. Then, press the reset button. If the AT commands time out, try to press the reset button again. For some reason, this sometimes works!

Also, once you see the text "The AT host sample started", wait a few seconds & then try pressing the AT+CFUN? button. That should then make the at client example work.

[stevenminnick]

Multiple resets didn't seem to help. 

But blowing out the memory with nrfprog.exe and the programing the secure boot and at client with nrfprog.exe DID work.  It seems to be working fine. 

Why would that work and using the nRFConnect Programming GUI, erasing all and then programming both of those with that tool (multiple times) not work?  On the nRFConnect Link Monitor, both show the same behavior in the terminal window.  Except programming the same HEX files with the GUI produced AT Timed Out and then programming with the command line tool seemed to fix it.

That's weird.  Glad it's working but I'm a little worried about functionality in the future, if something weird happens as I develop code what is my bug and what is whatever happened here. 

[Pratik]

I have similar problem. But in SDK v0.4.0 secure_boot is not available ? Ads it is gone there must be some replacement/other config for replacing it in new version. Can you please clarify it ? Do i need to use old SDK for AT client ?

With new SDK there are 2 Board options for nrf9160 which are nrf9160_pca10090 & nrf9160_pca10090ns.

if i select nrf9160_pca10090 then i get build error for at_client example & with nrf9160_pca10090ns i can build and run, but there is no response for at commands

can you please help me out..?

[stevenminnick]

I didn't notice that till you said it, but yes.  SecureBoot is gone.  I'm not sure why.  You could roll back to 0.3.0 and get it.  Or I had it and included it here.  if you load that on your board that had the at client

nrfjprog.exe --program Secure_Boot.hex --sectorerase -r -f nrf91 --verify

Reset and see if it runs.  Or even make sure the compiled hex file AT_Client.hex (that you made) is loaded with the same tool.  See if that helps. 

I would also like to know what happened to the secureboot project and what we should use now?

0028.Secure_Boot.hex

[Ruth Fuchss]

The Secure Boot sample has been renamed to Secure Partition Manager: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/0.4.0/nrf/samples/nrf9160/spm/README.html

The change is mentioned in the release notes for 0.4.0.

[stevenminnick]

Totally missed that.  Thanks!  I think loading the SecureBoot/SecurePartitionMananger might help Pratik to get his at_client to run and respond.

[buono]

I'm having the exact same issue. I'm trying to follow your suggestions, but I'm a bit confused. Are you saying you need to load 2 hex files? The SPM first and then the AT_client? Is there a special way of doing this?

[stevenminnick]

I believe that, yes you have to load 2 different hex files. 

nrfjprog.exe --program at_client.hex --sectorerase -r -f nrf91 --verify

nrfjprog.exe --program Secure_Partition_Manager.hex --sectorerase -r -f nrf91 --verify

You can also use the programmer too in the nRF Connect GUI that lets you load multiple hex files.  You can have your bootloader loaded and then just run out of the IDE as well.

That all being said, I'm still having trouble with the new 0.4.0 version of the AT client, was going to make a new thread about that. But this is what I did with the 0.3.0 version. 

[buono]

Thanks for the reply! I tried using the nRF Connect GUI first, but it said the HEX files have overlapping data. I tired using the command line with the command you gave above, but  still dont think its working.  When I reset the DK the output in the terminal window is 

***** Booting Zephyr OS v1.14.99-ncs1 *****

The AT host sample started

Shouldn't there be a bunch of other lines related to the SPM first before the AT host starts? (Still getting the AT timeout error if I send one after the output above)

[stevenminnick]

yes there should be.  And for some reason the 0.4.0 version of the AT Client writes itself to address 0 instead of 40000 (or whatever, I'm pulling that from memory).  If you take the secure boot I posted above, or take the SPM from 0.4.0 and load that.  And then take AT Client from 0.3.0 (which I can post here), it writes itself to address 40000.  so if you flash both it will give you the bunch of stuff from the SPM and then the AT client and that works.  If you load the old radio firmware 0.6.8 on there, the whole thing works (at least for me). 

But if you load the new 0.4.0 AT Client it overwrites the SPM and all you get is the AT Client, which I don't think works anyway.  At least I haven't figured out how it works. 

at_client_snarkyPrintf.hex

WARNING, I get a bit strange when I've been working on things like this and to make sure I was really flashing the code I was compiling I added a snarky/rude line.  I don't feel this way, or am angry, but if you see this line you know 100% for sure it's not Nordic's stock code.  I was thinking, what could I write that they would never put in code.  And so it exists.

[buono]

LOL, ok thanks! I'll try this out tomorrow.