nRF5340 current consumption issues

RE: nRF5340 current consumption issues

frax84 — Fri, 11 Aug 2023 17:17:13 GMT

It seems you're going in the right direction. As we supposed, latency was the key about the different intervals. For the power the things are a bit more complicated. Variables are really a lot, from hardware to software. I wish you good luck :)

RE: nRF5340 current consumption issues

John Lee — Fri, 11 Aug 2023 01:05:17 GMT

Current peaks on both boards with slave latency set to zero.
Peaks at the same interval (60 ms) on both boards.

<52832>

<5340>

But even over the same connection interval, they show different average currents, so I'll check that out as well.

RE: nRF5340 current consumption issues

frax84 — Thu, 10 Aug 2023 10:46:29 GMT

Did you try to set latency to 0 on both boards to check if these differences disappear? Latency is not so trivial to consider during packet exchange. I think it's worth a shot

Edit: sorry, I missed your 3rd bullet point.

RE: nRF5340 current consumption issues

John Lee — Thu, 10 Aug 2023 09:02:48 GMT

Added information that has not been explained.
In the case of the 52832 board, NCS is not used, and the sdk in use is as follows.
52832: nRF52 SDK 17.1.0
5340: NCS 2.3.0
Small differences are acceptable as they do not use the same SDK.

1. Both boards use the same 32MHz crystal and use internal RC. (32kHz is not used.)
2. Apply PM at 5340 board.
(CONFIG_PM, CONFIG_PM_DEVICE)
3. After removing the slave latency, I will upload the test results.

My question is why the interval between sending and receiving empty packets is different on both boards, although the slave latency is the same.
Is there any additional information I should check?

RE: nRF5340 current consumption issues

frax84 — Thu, 10 Aug 2023 07:31:13 GMT

Hi John, it's hard to make good hypothesis because you didn't provide neither code nor schematics. If I were in your shoes:

I would firstly check from the hardware side. For example, are you using an external crystal for Bluetooth? If yes, is the same in the two boards? Crystals are used to measure time flowing. If the accuracy of the crystal is not the same, or if you're using the internal oscillator, things can change.
Secondly, I would check if your board settings are the same (i.e. do you use PM module? The nrf connect SDK version is the same?)
Finally, I would make a test with slave latency = 0. Slave latency affects how frequently peripheral and central devices "can ignore" each other so this could play a role in addressing your issue.

RE: nRF5340 current consumption issues

John Lee — Thu, 10 Aug 2023 00:33:29 GMT

Looks like my guess is wrong.
The master sometimes fails even on the 52832 board, and rssi seems to be more unstable.

<52832>

<5340>

So why is my 5340 board getting empty packet connection checks more often, even though it uses the same connection interval, slave latency?

RE: nRF5340 current consumption issues

frax84 — Wed, 09 Aug 2023 10:11:14 GMT

Hi John,

i'm wondering if you can log the RSSI of the packets exchanged. In general, if antenna matching is poor (due to bad matching network or interferences or whatever), you should notice an RSSI averagely lower of several dBs. It's just a coarse check, but maybe it can give you some hint on the issue.