Documented or undocumented method for lowering NRF52 radio Rx power consumption?

[Glenn Zelniker]

I have an application that uses the nRF52840 for BLE in central mode. This application is battery powered. Basically, the device is listening for beacons and logging which beacons it sees over a given time period. As everyone knows, BLE Rx consumes far more power than Tx. I've done everything I can to minimize the power consumption: sleeping whenever possible, getting the scan window and scan interval as small/big as possible, using the DC/DC converters, etc. But I still need to bring the power consumption down. Because the beacons are advertising at a high rate and also because my device will always be close to the beacons, the receiver will still see the beacons even if the receiver is using minimal gain in its AGCs, LNAs, or the like.

While the Tx part of the radio has its power output exposed via an API and/or processor registers, I've not been able to find anything similar for the Rx. If anyone has any tips or tricks, I'd love to know. It would be great if one of the Nordic engineers following this forum could share some secrets!

[Kenneth]

There really isn't much (if any) you can tune here. The RX current is fixed for a specific nRF variant (depending on DCDC) and will be enabled as long as it's actively scanning for an advertiser, but you may tune the scan window and scan interval to more rarely listen for advertisers. You may also find that some devices in the nRF52-series use less current in RX, for instance check out the nRF52810. Though if you really need to reduce the RX current you should look at the upcomming nRF53-series.