NUS example, when connected, see current pulse 50ms interval

RE: NUS example, when connected, see current pulse 50ms interval

Jared — Fri, 28 Feb 2025 14:29:46 GMT

Hi.

[quote user="James168"]

Yes, using the latter peripheral_uart sample to send packet to central_uart, the current consumption is higher than online power profiler. I disable the UART in prj.conf and use timer expire to send packet from peripheral to central.

2) I send 13 bytes from nRF52840 dongle (peripheral_uart) to nRF52832 DK (central_uart), and change connection interval to 100ms, so the measured current consumption is about 102 µA, and the online power profiler is about 79 µA as the following.

[/quote]

Online power profiler application does only estimate the current consumption of the BLE stack. Anything extra in the application such as timers will consume additional current that is not taken into consideration by the estimation. I think what you measure is within what is acceptable.

regards

Jared

RE: NUS example, when connected, see current pulse 50ms interval

James168 — Fri, 21 Feb 2025 07:25:04 GMT

1) I attach the code, and most of the modified codes are between line 587 to line 692, the other modifications are used to disable the LED and UART.

To use send_data() to send the packet 10s interval, the connection interval is 100ms.

devzone.nordicsemi.com/.../4188.peripheral_5F00_uart_5F00_v290_5F00_low_5F00_power_5F00_250221_5F00_connected_5F00_send_5F00_data_5F00_10s_5F00_interval.7z

2) About run the power profile sample, I did press the button 1 or button 2, and I can see entering the system off mode from the log.

I doubt the sample use

bt_le_ext_adv_start(adv_set, &connectable_start_param);

to send the advertising, does the wireshark can capture the extended advertising packet?

RE: NUS example, when connected, see current pulse 50ms interval

Jared — Thu, 20 Feb 2025 10:56:44 GMT

ok, on a second thought, the power profiler sample does not support the dongle as it requires you to press button 1 to wakeup the device from sleep and start advertising.

Maybe you can share the modified code that you use here, and I'll check if I can give you any suggestions to decrease the current.

[quote user="James168"]I used button to trigger send the packet before, and today I change to use timer interval to send packet when timer is expired and the current pulse happened just once. It seems normal now. But the power consumption is large than the "Online Power Profiler for Bluetooth LE" about 30uA.[/quote]

regards

Jared

RE: NUS example, when connected, see current pulse 50ms interval

Bhagyashree badiger — Thu, 20 Feb 2025 07:02:30 GMT

How did you measure this current.

RE: NUS example, when connected, see current pulse 50ms interval

James168 — Tue, 18 Feb 2025 11:01:46 GMT

1) I am using nrf52840 dongle for test, but using nrf52840 DK and sw6 to "nRF only" almost the same current value.

2) Can power profiler sample packet be captured by wireshark? I see nothing when advertising.

RE: NUS example, when connected, see current pulse 50ms interval

Jared — Mon, 17 Feb 2025 14:45:25 GMT

Hi,

Have you set the development kit to nrf Only on switch 6?
I think the Bluetooth power profiler sample is better for power profiling.

Jared

RE: NUS example, when connected, see current pulse 50ms interval

James168 — Mon, 17 Feb 2025 09:13:36 GMT

Hi,

1) Yes, using the latter peripheral_uart sample to send packet to central_uart, the current consumption is higher than online power profiler. I disable the UART in prj.conf and use timer expire to send packet from peripheral to central.

3) I have read the following data.

docs.nordicsemi.com/.../power_general.html

RE: NUS example, when connected, see current pulse 50ms interval

Jared — Fri, 14 Feb 2025 14:13:04 GMT

Ok so the original issue has been resolved, and now the issue is that you measure a higher average current than expected?

Are you using the peripheral nus sample from Zephyr or peripheral UART sample from NRF folder? Are you now measuring on central or peripheral?

You say that you measure 30 µA more than expected when using the online power profiler. Exactly how much do you measure?

regards

Jared

RE: NUS example, when connected, see current pulse 50ms interval

James168 — Tue, 11 Feb 2025 10:29:43 GMT

Hi,

I used button to trigger send the packet before, and today I change to use timer interval to send packet when timer is expired and the current pulse happened just once. It seems normal now. But the power consumption is large than the "Online Power Profiler for Bluetooth LE" about 30uA.

RE: NUS example, when connected, see current pulse 50ms interval

James168 — Mon, 10 Feb 2025 10:13:10 GMT

1) connection interval is unmodified, the default values are

#define BT_GAP_INIT_CONN_INT_MIN 0x0018 /* 30 ms */
#define BT_GAP_INIT_CONN_INT_MAX 0x0028 /* 50 ms */

I think maybe the sniffer can't capture all packets for channel hopping condition, so the interval changed to 100ms in the wireshark.

I got empty PDU packets interval 50ms sometimes in the wireshark.

2) To send "hello\n" once waveform as the following, the sampling rate is 32k/s, maybe not the real waveform.

zoom in

It seems have 6 spikes matching the 6 bytes data, but why it continued many times in 10ms interval?

RE: NUS example, when connected, see current pulse 50ms interval

Jared — Fri, 07 Feb 2025 14:21:32 GMT

Can you zoom into one of the "pulses"?

RE: NUS example, when connected, see current pulse 50ms interval

James168 — Fri, 07 Feb 2025 14:01:15 GMT

Hi Jared,

I have another question to send "Hello\n" 6 bytes about current consumption, can you reply also?

RE: NUS example, when connected, see current pulse 50ms interval

Jared — Fri, 07 Feb 2025 12:07:14 GMT

Hi there,

That looks indeed like current consumed from the Radio, is the sample unmodified?

Could it be that the interval starts at 50 ms and then increases to 100 ms later? Do you see the same if you measure current after some time has elapsed?

regards

Jared

RE: NUS example, when connected, see current pulse 50ms interval

James168 — Fri, 07 Feb 2025 10:34:39 GMT

I send "Hello\n" 6 bytes from peripheral to central to test peripheral TX current consumption, and I see many pulses more than 6 in the power monitor. It continued about 420ms, how to explain it and how to improve it?

I expect to see the current like the "Online Power Profiler for Bluetooth LE".

The following is the power monitor screen captured,

zoom in