DFU for external BLE Sensor

[davidpatton]

Hi,

  I have a current project that is based on the nRf52840.  This project acts both as a peripheral and a central.  I have a need to update the firmware on a remote BLE sensor using DFU, i.e., I need to do exactly what the nRfConnect application does when it updates a peripheral firmware via DFU.  My thought was to use the nRf52840 dongle and develop this code on my PC and then port it to my embedded system.  I also thought the best starting point would be the source code for the nRfConnect application which I would port it but I see from user comments that nordic did not release the source code for this.  Is it possible to get this source code or is there another example that demonstrates what I need to accomplish?

Thanks!

[Vidar Berg]

Hi,

The source code for the nRF connect desktop app is actually available on Github here: https://github.com/NordicSemiconductor/pc-nrfconnect-ble. It's the source code for the mobile version that's not available.

As another alternative, you also have the python scripts in pc-nrfutil. The script responsible for the OTA DFU part is here: https://github.com/NordicSemiconductor/pc-nrfutil/blob/master/nordicsemi/dfu/dfu_transport_ble.py

Best regards,

Vidar

[davidpatton]

Hi,

  I am a bit confused and am hoping that you can help.  I have a Laird BT610 sensor and when I connect to it it does not show a Secure DFU service; however, I can do an over the air update of this sensor using nRfConnect and a proper firmware.bin file for this sensor. The sensor does advertise the SMP Serviice.  Is nRfConnect using this service to perform the firmware update?

Thanks,

Dave

[Vidar Berg]

Hi Dave,

I am sorry for the confusion. I assumed your FW was based on our nRF5 SDK which uses a different DFU protocol.  So my initial reply does not apply to your case. As you may know, the nRF connect SDK is relying on the DFU protocol from MCUmgr for FW updates over BLE.

Here are the MCUmgr libraries we use for our ios and android apps:

https://github.com/NordicSemiconductor/Android-nRF-Connect-Device-Manager

https://github.com/NordicSemiconductor/IOS-nRF-Connect-Device-Manager

Best regards,

Vidar

[davidpatton]

Hi, my code is based on the nRF5 SDK and runs on a nRf52840.  I am trying to send a firmware update from my nRf52840 to an external BLE sensor via whatever means I need to use.  The external sensor is a BT610 from Laird.   When I use the nRFConnect app to connect to the BT610 sensor I do not see the BT610 advertising a Secure DFU service.  The BT610 does advertise an SMP Service.  So I guess I need an nRF5 SDK example for how to connect to the SMP service and discover it's characteristics so I can read/write to them.  I have not been able to find any nRF5 SDK examples for this.

Thanks,

Dave

[Vidar Berg]

I see, thanks for the clarification. The fact that the laird module  advertises the SMP service indicates that it only supports the mcumgr protocol. And the bad news is that there is no SMP implementation in the nRF5 SDK, so this is something you would have to do from scratch.

A good start would maybe be to make the SMP GATT client service to interface with the SMP server on the BT610.