Max power and average power calculations for NRF52840

RE: Max power and average power calculations for NRF52840

Dmitry — Sat, 23 May 2020 07:47:10 GMT

It's not my tool, it's written by Nordic, I just put a link here 🙂

I can't say what values are used for calculation but believe the result is close to real drawings.

RE: Max power and average power calculations for NRF52840

Dan Colob — Fri, 22 May 2020 22:55:35 GMT

Also, how are you determining the durations?

RE: Max power and average power calculations for NRF52840

Dan Colob — Fri, 22 May 2020 22:52:02 GMT

Ok thanks.

1. so for the online calculator, how did you get the current for the pre-processing stage for Advertising connected? I cannot find that current value anywhere in data sheet.

2. How did you get the current value for transmit? In the data sheet for 0dB, the value is 4.8 mA, but on the calculator it is 6.7 mA?

RE: Max power and average power calculations for NRF52840

Dmitry — Fri, 22 May 2020 21:02:29 GMT

For connected mode, it's an LL payload (3-byte ATT header + your data), and can be up to 251 bytes.

RE: Max power and average power calculations for NRF52840

Dmitry — Fri, 22 May 2020 20:57:35 GMT

Hmm.. it's the size of your advertising data - the one you passed to sd_ble_gap_adv_set_configure().

RE: Max power and average power calculations for NRF52840

Dan Colob — Fri, 22 May 2020 20:51:13 GMT

Ok, so is the "TX payload per event" option on the online calculator how much over your payload from max payload is?

RE: Max power and average power calculations for NRF52840

Dmitry — Fri, 22 May 2020 20:45:50 GMT

Max payload size of a simple advertising is 31 bytes. Larger payloads are possible when using extended advertisings (a feature of Bluetooth 5), seems profiler have no support for them yet.

RE: Max power and average power calculations for NRF52840

Dan Colob — Fri, 22 May 2020 20:22:40 GMT

Ok, is the "TX payload per event" option how much over your payload from max payload is? I think from the spec sheet I could say the max payload is 251 bytes. Can you please confirm?

RE: Max power and average power calculations for NRF52840

Dmitry — Fri, 22 May 2020 20:06:56 GMT

Not only. There is a "Role" menu in BLE settings column, by default it is set to connectable advertising.

RE: Max power and average power calculations for NRF52840

Dan Colob — Fri, 22 May 2020 20:01:17 GMT

This looks like it is for when the device is connected, is there something like this for when the device is advertising, since this will take the most power?

RE: Max power and average power calculations for NRF52840

Dmitry — Fri, 22 May 2020 17:05:02 GMT

Look at Online Power Profiler