Are OTA updates possible on non-connectable beacons ?

[Siddhesh]

We are working on non connectable beacons without any external I/O. They simply have a power and ground. Is it possible to perform OTA updates on such devices. 
Is there any way to trigger bootloader mode without any connection/external trigger ?

[Einar Thorsrud]

Hi Siddhesh,

You need some way to trigger the bootloader to enter DFU mode. This could be accomplished by asserting a pin by pressing a button during power up, but as you write you don't have any external I/O I assume that is not an option. Then the other alternative is to send a command over the air.

There are a few ways you could send data to your beacon over the air, but the typical would be to use connectable advertising, allowing a central (phone or similar) to connect and initiate the DFU process. The SoftDevice do not support simultaneous connectable advertising and non-connectable advertising, through, which would perhaps have been the most obvious solution. An alternative is to reconfigure advertising regularly, switching between non-connectable advertising (acting as a beacon), and using connectable advertising (for administration, such as DFU). This is similar to what is done in Eddystone.

The  Buttonless DFU Template Application demonstrates how you can trigger DFU mode over BLE in a connection.