DFU Peripheral to Central?

[Arepa]

Hi all

Is possible have DFU in the peripheral side to update a Central app program? Is there example doing it?

I have a Peripheral (custom board nRF52 dongle) connected to a PC, and I want to update the application program in the Central side (remote battery powered) using DFU.

Is possible to do a DFU Periphera-to-Central role instead of Central-to-Peripheral?

Thanks

[Hung Bui]

Hi Arepa,

Does it have to be the remote device running in central mode when you are doing DFU ?

We currently don't have an example for that.

But please be noted that the S132 is capable of running in both central and peripheral. So there is an option that you run your device in central mode, then you send a command from the peripheral connected PC that the remote device switch to bootloader and starts as a peripheral. You then can also switch the peripheral into central mode to do DFU update.

With this solution you only need to make the DFU master part which run on the PC. (We don't have this part yet). Alternatives are you can update using a phone or from PC via nrfutil tool (if you run the dongle with connectivity firmware).

If you really have to keep the remote device in central role, then you need to implement your own bootloader. You can reuse many parts from the default bootloader, you can set up a GATT server on the central side and receive image to that server. Only difference here is the DFU master advertise, the DFU target connects instead of the other way around.

[Arepa]

Hi Hung,

I think the remote device running in central role could be more battery efficient because the most time it is listening instead of transmiting (advertising data). Please correct me If I am wrong.

In case the keep my current setup (Central as remote device and Peripheral for a linux PC) That is what I was thinking about switch roles to perform the DFU, but I will make more "complex" the code.

The Idea is if a future I need a update for the Remote devices. I will sent the update using the peripheral attached to the PC. This same peripheral in normal operation is monitoring the remote devices.

So I may switch the PC attached peripheral to central, and the remote Central to Peripheral then perform the DFU over the air

Thanks