BLE, SAADC and UART high power consumption

RE: BLE, SAADC and UART high power consumption

Jared — Thu, 22 Jun 2023 12:58:33 GMT

Hi,

Is it stuck in the callback handler or does it return to the main loop? If it's stuck then you need to move it away from interrupt context to main context. You should then use a flag instead that you set in the callback handler so signalize to the main loop to uninit /init the driver.

You also need to init the channel again as well, basically setup everything that you did during the first time again as well.

regards

Jared

RE: BLE, SAADC and UART high power consumption

B3RC1K — Thu, 22 Jun 2023 12:16:51 GMT

[quote userid="73165" url="~/f/nordic-q-a/100705/ble-saadc-and-uart-high-power-consumption/432495"]

yes, you would have to call nrf_drv_saadc_uninit() when you're done using the SAADC and then call saadc_sampling_event_init() before you start using it again,

regards

[/quote]

Any idea how to do that. I tried placing it in callback but it did not work. Could not see any samples being sent. Then i tried to put it in main that also did not work. Is there some kind of function to init it again when it's needed?

RE: BLE, SAADC and UART high power consumption

Jared — Thu, 22 Jun 2023 11:05:31 GMT

I got the example to work with low power mode by moving the call of saadc_init() before saadc_sampling_event_init(), but I can't say that I measure considerable lower current with this mode enabled, which seems to indicate that the low power mode is not fully functional. But since you mentioned that were you able to measure lower power when enabling it earlier, could you try moving the function call and see if you measure lower current?

[quote user="B3RC1K"]Could You tell me how to do that. I tried using uninit function but seems like it disables saadc permamently instead of only between samples.[/quote]

yes, you would have to call nrf_drv_saadc_uninit() when you're done using the SAADC and then call saadc_sampling_event_init() before you start using it again,

regards

Jared

RE: BLE, SAADC and UART high power consumption

B3RC1K — Thu, 22 Jun 2023 10:15:50 GMT

[quote userid="73165" url="~/f/nordic-q-a/100705/ble-saadc-and-uart-high-power-consumption/432460"]The suggested alternative to get low power is to uninitialized the SAADC driver between samples,[/quote]

Could You tell me how to do that. I tried using uninit function but seems like it disables saadc permamently instead of only between samples.

RE: BLE, SAADC and UART high power consumption

Jared — Thu, 22 Jun 2023 08:15:25 GMT

Ok, I was able to reproduce the same results consistently and I did some digging and found similar cases in regards to low power mode. It seems to be some events that aren't triggered internally in the driver when it's enabled and in scan mode. The suggested alternative to get low power is to uninitialized the SAADC driver between samples,

regards

Jared

RE: BLE, SAADC and UART high power consumption

B3RC1K — Thu, 22 Jun 2023 07:28:45 GMT

[quote userid="73165" url="~/f/nordic-q-a/100705/ble-saadc-and-uart-high-power-consumption/432449"]Just to be clear, the nRF Connect Toolbox app not nRF Connect mobile app right?[/quote]

Tried both nRF connect and nRF toolbox mobile apps. On both the result is the same.

RE: BLE, SAADC and UART high power consumption

Jared — Thu, 22 Jun 2023 07:25:19 GMT

[quote user="B3RC1K"]I tried with nRF connect.[/quote]

Just to be clear, the nRF Connect Toolbox app not nRF Connect mobile app right?

RE: BLE, SAADC and UART high power consumption

B3RC1K — Thu, 22 Jun 2023 07:10:40 GMT

[quote userid="73165" url="~/f/nordic-q-a/100705/ble-saadc-and-uart-high-power-consumption/432324"]Are you using the nRF Connect Toolbox mobile app when testing this? The screenshot looks like a third party external app, please test with nRF Connect Toolbox.[/quote]

I tried with nRF connect. It is the same. The values dont change.

[quote userid="73165" url="~/f/nordic-q-a/100705/ble-saadc-and-uart-high-power-consumption/432324"]Can try to change to low power mode by changing the NRFX_SAADC_CONFIG_LP_MODE config in the sdk_config,h file? It will set the low_power variable of the config struct accordingly.[/quote]

Did that. The same result. Data does not get printed.

RE: BLE, SAADC and UART high power consumption

Jared — Wed, 21 Jun 2023 12:56:57 GMT

Strange,

Ok, lets continue with the unmodified ble_app_uart__saadc_timer_driven__scan_mode to limit the amount of possible root causes.

[quote user="B3RC1K"]

UART data sent over BLE. Like on the screenshot:

With saadc_config.low_power_mode = true I can not see anything in here.

[/quote]

Are you using the nRF Connect Toolbox mobile app when testing this? The screenshot looks like a third party external app, please test with nRF Connect Toolbox.

2. Can try to change to low power mode by changing the NRFX_SAADC_CONFIG_LP_MODE config in the sdk_config,h file? It will set the low_power variable of the config struct accordingly.

regards

Jared

RE: BLE, SAADC and UART high power consumption

B3RC1K — Wed, 21 Jun 2023 07:32:16 GMT

Hello,

[quote userid="73165" url="~/f/nordic-q-a/100705/ble-saadc-and-uart-high-power-consumption/431997"]ble_app_uart__saadc_timer_driven__scan_mode example and you'll see that it will continue to transmit data even when low power is configured in the sdk_config.h file.[/quote]

I tried an example that You provided and that does not seem to be true in my case. When setting low power mode to true I can not see any information being sent to app. When I comment out this line everything goes back to normal.

[quote userid="73165" url="~/f/nordic-q-a/100705/ble-saadc-and-uart-high-power-consumption/431997"]Are you printing out data over the serial log as well?[/quote]

I tried that as well. When low power mode set to true printing over the serial stops.

Unfortunately I'm not getting any error code when that happens. The terminal just remains empty. This happens in my code and the code you provided.

regards

Hubert

RE: BLE, SAADC and UART high power consumption

Jared — Tue, 20 Jun 2023 11:59:45 GMT

Hi,

I think you need to debug your application and check if it asserts. Setting low_power_mode = trrue shouldn't stop the transmission of data. For example, you can try to do the same in the ble_app_uart__saadc_timer_driven__scan_mode example and you'll see that it will continue to transmit data even when low power is configured in the sdk_config.h file.

Are you printing out data over the serial log as well? Do they also stop once you configure low_power_mode=true ?

regards

Jared

RE: BLE, SAADC and UART high power consumption

B3RC1K — Tue, 20 Jun 2023 08:51:38 GMT

[quote userid="73165" url="~/f/nordic-q-a/100705/ble-saadc-and-uart-high-power-consumption/431809"]Are you referring to log data in this case?[/quote]

UART data sent over BLE. Like on the screenshot:

With saadc_config.low_power_mode = true I can not see anything in here.

RE: BLE, SAADC and UART high power consumption

Jared — Mon, 19 Jun 2023 14:23:57 GMT

[quote user="B3RC1K"]I could not get settings beyond little above 200uA so that's not even close to my consumptions from multimeter.[/quote]

I meant, what parameter were you using to get 10 µA with the online power profiler?

Using the SAADC will add on the power consumption for sure, the EasyDMA current is around 700 µA itself. Best option to completely remove is to disable the SAADC when you're done sampling by calling nrfx_saadc_uninit().

[quote user="B3RC1K"]

4848.ble_app_uart_pca10056_s140.hex

Here is the hex. Could You let me know what average current consumption You get?

[/quote]

With this I'm measuring avg 774 µA,

[quote user="B3RC1K"]

And here is the hex file for the saadc_config.low_power_mode = true version so that You can see what I am talking about with not being able to see any data.

7317.ble_app_uart_pca10056_s140.hex

[/quote]

Are you referring to log data in this case?

regards

Jared

RE: BLE, SAADC and UART high power consumption

B3RC1K — Mon, 19 Jun 2023 09:51:45 GMT

Hi,

Any news regarding this topic?

regards

Hubert

RE: BLE, SAADC and UART high power consumption

B3RC1K — Wed, 14 Jun 2023 12:06:27 GMT

And here is the hex file for the saadc_config.low_power_mode = true version so that You can see what I am talking about with not being able to see any data.

devzone.nordicsemi.com/.../7317.ble_5F00_app_5F00_uart_5F00_pca10056_5F00_s140.hex

RE: BLE, SAADC and UART high power consumption

B3RC1K — Wed, 14 Jun 2023 11:49:11 GMT

Hello,

[quote userid="73165" url="~/f/nordic-q-a/100705/ble-saadc-and-uart-high-power-consumption/430980"]What parameters did you use?[/quote]

I could not get settings beyond little above 200uA so that's not even close to my consumptions from multimeter.

[quote userid="73165" url="~/f/nordic-q-a/100705/ble-saadc-and-uart-high-power-consumption/430980"]Could you upload a precompiled hex that I could flash to my board? There is some dependencies error when I'm trying to build your project.[/quote]

devzone.nordicsemi.com/.../4848.ble_5F00_app_5F00_uart_5F00_pca10056_5F00_s140.hex

Here is the hex. Could You let me know what average current consumption You get?

[quote userid="73165" url="~/f/nordic-q-a/100705/ble-saadc-and-uart-high-power-consumption/430980"]How, please specify? Any runtime errors?[/quote]

When I set saadc_config.low_power_mode = true; in saadc_init the power drops significantly to around 50uA, unfortunately when I connect to the board with my phone I can not see any UART data coming in anymore in the app.

[quote userid="73165" url="~/f/nordic-q-a/100705/ble-saadc-and-uart-high-power-consumption/430980"]What do you mean by monitoring functionality, monitor the battery usage?[/quote]

Oh sorry, I should have been more precise. I meant monitoring my sensor voltage and battery voltage. And I meant using beacon and getting those two values to display via service/manufacturer data of beacon.

Best regards

Hubert

RE: BLE, SAADC and UART high power consumption

Jared — Wed, 14 Jun 2023 11:24:03 GMT

Hi,

[quote user="B3RC1K"]I have used to online power profiler and the average current is shown to be around 10 uA. I am not getting even close to that, so I assume its the uart, timer and easydma that cause the problem. However I'm measuring current with a multimeter connected to DK pins.[/quote]

What parameters did you use?

[quote user="B3RC1K"]Could You maybe test the code I uploaded if You are getting the same values?[/quote]

Could you upload a precompiled hex that I could flash to my board? There is some dependencies error when I'm trying to build your project.

[quote user="B3RC1K"]I tried using low power saadc but it unfortunately causes ble to not work.[/quote]

How, please specify? Any runtime errors?

[quote user="B3RC1K"]I wonder, if one of my main goals is battery life then is it a optimal approach that I'm using? Would it be possible to implement monitoring functionality with for example a ble beacon? [/quote]

What do you mean by monitoring functionality, monitor the battery usage? We have the CPU usage tracer in the power management library.

regards
Jared

RE: BLE, SAADC and UART high power consumption

B3RC1K — Wed, 14 Jun 2023 07:50:57 GMT

Hello,

I have used to online power profiler and the average current is shown to be around 10 uA. I am not getting even close to that, so I assume its the uart, timer and easydma that cause the problem. However I'm measuring current with a multimeter connected to DK pins. Could You maybe test the code I uploaded if You are getting the same values?

I tried using low power saadc but it unfortunately causes ble to not work.

I wonder, if one of my main goals is battery life then is it a optimal approach that I'm using? Would it be possible to implement monitoring functionality with for example a ble beacon?

Maybe You have some other suggestions?

Best regards

Hubert

RE: BLE, SAADC and UART high power consumption

Jared — Tue, 13 Jun 2023 11:02:14 GMT

Hi there,

The current consumption of your BLE application will depend on several factors such as connection parameters, DCDC, LFCLK, TX Power etc. You can use the Online Power Profiler tool to see how the different parameters affect the current consumption,

In addition there is some steps you can apply to decrease the current consumption of the SAADC peripheral, the low power SAADC example shows how using RTC instead of Timer, only enable EasyDMA during sampling, disabling UART and Enabling DC/DC will decrease the power consumption.

You'll already putting the chip into System On sleep between events,

regards

Jared