Unable to Write TLS credential during JITP on custom nRF9160 board

[shak2300]

Hello everyone

I created a custom board with reference to thingy:91 for the antenna part. The board is 50x50 mm in size.

I tested the board and there are no problems with the power supply, SIM, or sending AT commands. The peripherals work correctly and I tested my own program for UART communication. The LTE modem works, connecting after about a minute.

I use a J-Link EDU debugger for debugging.

The problem I am encountering is that I cannot insert the CA certificate into the nRF9160SiP. Once I have downloaded the JSON certificate from nRF Cloud, I use the Cellular Monitor application.

10:16:22.453 Updating CA certificate...
10:16:22.453 Unable to Write TLS credential
10:16:22.453 Updating client certificate...
10:16:22.453 Unable to Write TLS credential
10:16:22.453 Updating private key...
10:16:22.453 Unable to Write TLS credential
10:16:22.453 Certificate update completed

I can't proceed. Before uploading the file, I ran the AT+CFUN=4 command and verified that it was indeed in that state.

[Hakon]

Hello,

are you running a custom application or one of the SDK samples? Have you tried it on a DK?

[shak2300]

Hakon said:

are you running a custom application or one of the SDK samples?

Hi, I'm using a sample. I use at_client sample. 

Hakon said:

Have you tried it on a DK?

Yes I tried and work properly

[Hakon]

Seems like there is an issue with your board then. Does it work if you use the at%cmng command directly?

[shak2300]

Hakon said:

Does it work if you use the at%cmng command directly?

> AT%CMNG=1
%CMNG: 12,3,"9B0C8FE7D4B23027A282FBDDAA4A8FE6640C6E6F5D85F9005ACA8AE0BCED1ED4"
%CMNG: 12,4,"ED75D2209650827687DFC4F68F33ADF1A74E591253F694D80EFD63085C113B22"
%CMNG: 16842753,0,"0359B70CF6209FBC619243F8B2678C480D8B50F5B0D76399978F49527C2CA066"
%CMNG: 16842753,1,"D7642EF7F0D80BE03046F9B948B7F9EAA210C5EA85C59370515AD61BFED32B4F"
%CMNG: 16842753,2,"55D43151089247E1F78E150DB54C34413BDA97E035BA83D646A9929FF5A70F15"
%CMNG: 4294967293,10,"2C43952EE9E000FF2ACC4E2ED0897C0A72AD5FA72C3D934E81741CBD54F05BD1"
%CMNG: 4294967294,6,"7A9AF8725C83AE0BA1FBC3ADFB18499264B18A01A0773836C5DF12CF26BA46D7"
%CMNG: 4294967292,11,"2027C4699EAA90A414D33FA81B975C0FDEDEFB04A19CEA1ED43A8876CAD31E89"

I tried to enter them manually via UART, using the following commands:

AT%CMNG=0,16842753,0,‘<ca-cert.pem>’
AT%CMNG=0,16842753,1,"<client-cert.pem>’
AT%CMNG=0,16842753,2,‘<private-key.pem>’

All give me Okay, without error, but I can use nRFCloud

I use a TTL-3V3 cable. The nRF9160 is powered at 3.3V for both VDD and VDD_GPIO.

[Hakon]

shak2300 said:

All give me Okay, without error, but I can use nRFCloud

Have you confirmed with the at%cmng=1 command that the certificates were written properly to the modem?

[shak2300]

Hakon said:

Have you confirmed with the at%cmng=1 command that the certificates were written properly to the modem?

Yes, I used AT%CMNG=1 and confirmed that the certificates are present with sec_tag 16842753 at indices 0, 1, and 2. But nRF Cloud still doesn’t connect.

[shak2300]

I can connect to it via the nRF Serial Terminal and I use manually the AT commands, like the last comment.

I tried nRF Cloud utilis but I'm stack on this part:

C:\Users\shadi\OneDrive - Berner Fachhochschule\Desktop\utils\src\nrfcloud_utils>python device_credentials_installer.py --ca self_*_ca.pem --ca-key self_*_prv.pem --id-str nrf- --id-imei -s -d --verify --coap --port COM10

INFO Disabling LTE and GNSS...
ERROR Unable to communicate

[Hakon]

So if you are sure the certificates are correct, then I would assume there is something wrong with registering your device to nrfcloud. I will ask the nrf cloud team to provide some input.