Transmit only BLE hardware

[Amit]

Are there any nordic ICs that only have transmit capabilities? Would there be any power benefit to only supporting transmission if the application only needs to transmit (like iBeacon)?

[ovrebekk]

Hi Amit

We stopped doing transmit only devices a long time ago, there simply isn't that much to save in terms of chip cost by removing the RX chain.

All our current devices are transceivers (TX and RX capable) , but you can still use them in a transmit only fashion to reduce the average power if you want.

That said, our current BLE stacks will always use the receiver when advertising to pick up possible scan and connection requests. If you want to do transmit only broadcasting with a Nordic device today you would have to bypass the BLE stack and control the radio directly.

Cheers Torbjørn

[Gus Gustafson]

What about non-connectable advertisements? Is the receiver still active even in that case?

[RK]

That's a good question especially when we're talking about iBeacon type devices. I can see that there's little to be saved in the silicon costs by removing the receiver, but for battery life concerns in a transmit-only device it would be good to have the receive circuit entirely off if the device is non-connectable and non-scannable.

[David Edwin]

The BLE stack also allows the transmission of non connectable advertising that is transmit only, i.e. the receiver is not turned on. You can also directly control the radio using the timeslot API of the Softdevice or control the radio directly without the soft device. An example of using the timeslot API is posted here. NordicSemiconductor.github.io/nRF51-multi-role-conn-observer-advertiser

[David Edwin]

You are correct, the receiver is not turned on for non connectable advertising.