Is there a current sample or example using BLE indicate function?

[BenH303]

I did some searching through the samples and could not find any that use indications rather than notifications. I did find some references in other posts that are like 8 years old, but they don't seem to be accessible any more. 

I'm trying to program a liquid sensor that uses an nRF52840 to notify/indicate an Aduino Nano BLE base station when liquid is detected to trigger an alarm. After the liquid is detected and the base station alarm is activated, the sensor should shut off BLE and go into deep sleep, but it needs to stay awake if the base station is out of range and doesn't get the notification/indication right away. I have that working with notifications but if it detects liquid while the base station is out of range, the alarm is never activated. I can't seem to figure out how to send and receive the acknowledgement. I'm also open to suggestions on other ways of accomplishing this.

[Hieu]

Hi BenH303,

Since you are using the word "samples" I assume you are working on the nRF Connect SDK?

If so, there are two samples where BLE Indication is used:

nRF Sample Peripheral Running Speed and Cadence Service (RSCS)
This one uses the Running Speed and Cadence Service (RSCS) library, which implements all the indication setup.

Zephyr Sample Peripheral CSC
This one implements the service, which contains the indication setup, in main.c itself.

In case you are working on the nRF5 SDK, you can refer to the Cycling Speed and Cadence example.

Best regards,

Hieu

[BenH303]

Hieu,

Yes, I am using nRF Connect SDK. Thank you, I'll look those up.

At this point I'm thinking that it may be more straightforward to use an additional writeable characteristic. Once the base station has received the proper notification, it can write to that characteristic, which will allow the sensor to go into deep sleep.