Advertising Battery levels on a beacon

RE: Advertising Battery levels on a beacon

Carlos Villavicencio — Fri, 17 Feb 2017 23:40:48 GMT

Thanks Ole. Have you ported this to SDK 11 and softdevice 130?

RE: Advertising Battery levels on a beacon

GunMin — Fri, 24 Apr 2015 10:27:57 GMT

Ole Morten, your example(nrf51-ble-app-temp) is How does the search?

RE: Advertising Battery levels on a beacon

Chris Butler — Mon, 31 Mar 2014 19:24:09 GMT

Those links help a good bit. I am still struggling with how exactly the calculation works and how I can verify it. Testing my actual battery voltage gives me 3.0v outside of the circuit, testing it in the working circuit gives 2.85v, the ACD however gives 0x55( or 85%) out of 3.0v which would correspond to 2.55v. When using the devlopement board with USB power it reads 0x65 when the max voltage is set to 3.0v in the code. What would be causing this discrepancy?

RE: Advertising Battery levels on a beacon

Ole Morten — Mon, 31 Mar 2014 14:10:05 GMT

I'm not sure I understand your question, but is it covered by either of these? https://devzone.nordicsemi.com/index.php/using-adc-to-measure-battery-voltage https://devzone.nordicsemi.com/index.php/what-voltage-range-can-be-measured-with-the-adc In that example, the value that comes out of the ADC is converted to a value between 0 and 100 (0x64) and then sent over the air. Please note that I'd rather recommend using manufacturer specific data for this, instead of the service data used by the example. The reason the example uses service data is for backwards compatibility with earlier apps.

RE: Advertising Battery levels on a beacon

Chris Butler — Mon, 31 Mar 2014 14:06:24 GMT

Thanks a lot, this is exactly what I needed. I do have one question though, what does the battery reading the ADC sends back correspond to?

RE: Advertising Battery levels on a beacon

Ole Morten — Mon, 31 Mar 2014 09:59:28 GMT

This is actually implemented in the nrf51-ble-app-temp, available here, so I'd recommend you to take a look on it. In summary, it uses app_timer to trigger a periodic timeout, in which it uses the ADC to measure the battery level, and updates the advertisement data.