RE: DFU in nrf52840 using UART.

Vidar Berg — Mon, 30 Jan 2023 13:43:16 GMT

Hi Bose,

I think you will find it easier to rely on the existing DFU protocol rather than making a new protocol from scratch (even if the new one is less complex). If you decide to create a new protocol, you will not only have to implement it on the ESP, but also make adaptations to the existing bootloader on the nRF.

Maybe you have seen them already, but the message sequence charts for our serial DFU transport here: Serial should give a good overview of what packets the ESP would need to send to complete a DFU process.

The ESP will not need worry about the content of the .bin and .dat file, it just have to forward them to the nRF. The .dat file contains the init command (Init packet) which includes various metadata such as checksum values and version numbers along with the update request, and the .bin contains the FW image.

However, if you still prefer to handle storage of the update image yourself, you may have a look at the discussion in this post: nRF52840 : update from a LTEM modem

Best regards,

Vidar