Tips for minimising power usage

[Gavin]

I am making some NRF51822-based temperature sensor nodes, powered by CR2032 coin cells, and I would like to minimise power usage in order to maximise battery life. I am using an external TMP102 temperature sensor, transmitting the temperature using enhanced shockburst, and then powering down into SYSTEM ON to be woken back up by an RTC1 timer interrupt.

I have found I can almost double the number of reading/transmit/sleep cycles that I can get out of a coin cell by using lower transmit power. Starting at -30, and only increasing power when I have a sequence of no acknowledgments.

What other tips do people have for further minimising battery usage?

I read somewhere on this web-site that I should not leave pins floating. Should I be grounding the spare pins on the carrier-board to achieve this?

All ideas welcome.....

[Hung Bui]

Hi Gavin,

It's correct that you can improve the battery capacity by reduce the high pulse when transmitting.

There are some material that you can have a look. The first is this post from Stefan How to minimize current consumption for BLE application

The second is a very interesting article "High pulse drain impact on coin cell capacity" from Kjartan Furset (our Strategic Application Manager) on our WirelessQ magazine that you can find here.

There are 4 parts lasting from the issue Winter 2011 to issue Winter 2012. You can find the rest of them here.

[Gavin]

Thanks. I'll take a look.