RE: Cannot connect Thingy91 to NB-IOT or LTE-M network. Unable to load certificate due to buffer overflow

John Buckley — Thu, 17 Oct 2019 09:36:00 GMT

Hello Simon,

Thank you for your reply. I think the initial problem is that the iBasis sim card does not work in the UK. I then tried a standard O2 PAYG SIM card, but I now think that I need a specific NB-IoT card for the UK. I have ordered a SIM card and if that connects, I will then try to set the certificate as above.

Thanks,

John

RE: Cannot connect Thingy91 to NB-IOT or LTE-M network. Unable to load certificate due to buffer overflow

Simon — Tue, 15 Oct 2019 11:42:01 GMT

To start with, could you try to update to the newest modem firmware, and see if you are able to get a connection. Check out this link on how to do it.

[quote userid="67318" url="~/f/nordic-q-a/53179/cannot-connect-thingy91-to-nb-iot-or-lte-m-network-unable-to-load-certificate-due-to-buffer-overflow"]1) Do I need to load a certificate to get a connection?[/quote]

You don't need the certificates to get a connection to the network. You will need certificates to connect to nRF Cloud. If you want to connect to nRF Cloud, you only need to load the certificates if the old ones have been deleted, see this post.

[quote userid="67318" url="~/f/nordic-q-a/53179/cannot-connect-thingy91-to-nb-iot-or-lte-m-network-unable-to-load-certificate-due-to-buffer-overflow"]2) If so, is there a compiled firmware (.hex) that allows the certificate length as an AT command by default?[/quote]

Yes, you can load new certificate with thingy91_at_client_v0.2.3.hex. Can be download as part of firmware binaries found here

[quote userid="67318" url="~/f/nordic-q-a/53179/cannot-connect-thingy91-to-nb-iot-or-lte-m-network-unable-to-load-certificate-due-to-buffer-overflow"]3) If not, is there a template project that I can modify and compile so that I can load the certificate?[/quote]

I will look into this

Also, could you provide the whole log, not only "at_host: Buffer overflow, dropping 'b'..."

Best regards,

Simon