DFU over cellular modem

[Jeffrey Haynes]

We have a system where the nRF52840 is running a cellular modem. We’re using the stock secure bootloader for DFU from a PC. However, we would like the option of updating over the modem. Is it possible to have the nRF receive an update from the modem, store it somewhere, and then hand that off to the bootloader on restart?

[Hung Bui]

Hi Jeff, 

Currently we don't have an example of receiving image via cellular modem. However, we have example of doing DFU via UART. If your modem support UART it should be able to do the DFU. It's also possible to convert the transportation to SPI or other transportation. But you need to be able to control your modem and run code on it. 

[Jeffrey Haynes]

Thanks, that’s kind of what I figured. I was able to find a usb transport example but not a (non-usb) uart example. Could you point me in that direction?  I may be able load from qspi. 

[Hung Bui]

Do you have this example in your SDK ? \SDKv15.2\examples\dfu\secure_bootloader\pca10056_uart . Info about it here. Note that even with the USB DFU variant, it's still UART under the hood.