Upgrading VIA UART

[Ofir_A]

Hi Team,

We are using SLM SDK 2.4.0 and MFW 1.3.5

We moving forward to SLM SDK 2.5.2 and want to FOTA all our products outside, but, some have problems with cellular reception and we would like to try to upgrade them via UART.

We can download the file on Wi-Fi to our master MCU flash and then do the upgrade via UART.

Our nRF9160 is the slave and we have a master MCU.

How can we do this upgrade?

Are there any special AT commands?

[Menon]

Hello,

I was a bit confused while reading your query. So let's clarify that first. You have a master MCU, and you are trying to update nRF9160 using the master MCU. You want to achieve this by writing an image via UART from the MCU, right? You were trying to achieve FOTA, but due to a cellular reception issue, you are sticking to transfers via UART. Is my understanding of your issue right? Please clarify or correct me if I am wrong anywhere.

I think this is achievable. I recommend you take a look at the cellular smp_server sample.

Kind Regards,

Abhijith

[Ofir_A]

Menon said:

You were trying to achieve FOTA, but due to a cellular reception issue, you are sticking to transfers via UART. Is my understanding of your issue right?

Yes

To work in the Serial LTE Modem app

[Dmitry Krol]

I didn't understand how we can use this sample for upgrade modem firmware and serial LTE application from our MCU via UART? Can you tell us how you support it?

[Menon]

Hello,

Apologies for the delayed response. I understand that both of you work for the same company or product. When another user comments on the same thread, it changes the status of the case, which is why I took some time to look into it. In the sample I provided, it utilizes the serial recovery method using the SMP_server sample. Serial recovery mode enables the nRF9160 to enter a special state where it awaits firmware updates over a serial interface (typically UART). Upon reviewing the sample, you will notice that the UART interface of the nRF9160 SiP (System-in-Package) is connected to the UART interface of the nRF52840 SoC, which is used for updating the nRF9160.

I recommend checking out the SMP_server and mcumgr, which will provide you with a starting point for serial firmware updates. We also have a developer academy course that can help you gain a better understanding. Please excuse this if you are already familiar with the topics I mentioned.

When updating both the modem firmware and the LTE application via UART, ensure that your modem_firmware and lte_app_firmware functions correctly handle flashing the respective firmware images into their designated flash memory locations. Refer to the sections "Full modem firmware update from flash devices" and "DFU target."

Kind Regards,

Abhijith