Communicate Two Nrf?

[macir]

Hello there;

We want to develop a project using the nrf52 series.
We have two nrf52s.
The first one is in the center and connected to the mains and there is no battery problem.
The other will be in the user's pocket and run on battery. (cr2032)
Here's what we want to do.
When the user approaches the central device with nrf in his pocket, the two devices will communicate.
The NRF in the center will ask the other NRF for a password.
The nrf in the pocket will send the password from memory.
The battery life of the nrf carried in the pocket must be a minimum of 1 year.
How can we make this scenario?

Thanks.

[Simonr]

Hi Mustafa

First of all, making a device like what you're describing lasting a year on a coin cell battery seems rather optimistic. I don't think you'll be able to achieve that with the application you're describing.

For starters, I think you should check out some of our SDK examples. For example the ble_app_hrs_c example for your central device. And something like the ble_app_beacon or the ble_app_hrs example for the peripheral (pocket) device. Then you'll have to modify these two examples to do what you want. I don't think we have any examples implementing the password functionality you're describing, so you'll have to create a service for that yourself.

Things to have in mind:

• To reduce power consumption in the peripheral device, please follow our current consumption guide, which explains just about every way to reduce current consumption in the nRF5 series.
• For the central, you'll probably want it to scan all the time so that it won't miss any advertisement packets by the peripheral, as the peripheral shouldn't advertise too often to save power.
• If the password feature you're describing, is just to keep the connection secure, I think a more power-efficient way to go about it would be a whitelist or similar, which is used in the _hrs examples I linked to.

Due to the summer holidays in Norway, our support team is understaffed this week, and delayed replies must be expected. Sorry for the inconvenience!

Best regards,

Simon

[awneil]

Simonr said:

our current consumption guide, which explains just about every way to reduce current consumption in the nRF5 series

Actually, it just says nRF51 - is it all equally applicable to nRF52? Are there any additional considerations and/or opportunities with nRF52 ?

[Simonr]

A few things when it comes to the nRF52840, which has two internal regulators instead of one etc. But the current consumption guide for the nRF51 series is still relevant to the nRF52 series.

Best regards,

Simon