Migrating SAADC Low Power from SDKv11 to v12

RE: Migrating SAADC Low Power from SDKv11 to v12

bjorn-spockeli — Thu, 20 Apr 2017 05:39:08 GMT

Happy to help :)

RE: Migrating SAADC Low Power from SDKv11 to v12

labi — Wed, 19 Apr 2017 19:45:50 GMT

Thanks Bjorn!

RE: Migrating SAADC Low Power from SDKv11 to v12

bjorn-spockeli — Wed, 19 Apr 2017 06:47:21 GMT

Hi Labi, if the low power mode bit is set in the config struct, then it will result in the SAADC peripheral initializing when sampling and uninitializing when sampling is complete. This will enable EasyDMA only during sampling, but leave it disabled when not sampling. The EasyDMA consumes around 1.5mA when enabled. This feature was based on this Github example.

RE: Migrating SAADC Low Power from SDKv11 to v12

labi — Tue, 18 Apr 2017 18:47:37 GMT

Hi,

Is there any documentation on the low_power_mode bit in nrf_drv_saadc_config_t somewhere or some code example showing what it does and how to use it? That would be greatly helpful!

Thank You, Labi

RE: Migrating SAADC Low Power from SDKv11 to v12

bjorn-spockeli — Fri, 18 Nov 2016 12:21:02 GMT

Hi Kevin,

A low power mode was added to the SAADC driver in SDK 12.x. You enable it by setting low_power_mode to 1 in the nrf_drv_saadc_config_t struct.

If you still want to port the GitHub example, then as you have coorectly pointed out, you have to edit the sdk_config.h file. I recommend that you start with the sdk_config.h file from the ble_app_template, which includes all the peripheral settings( the examples only include the peripherals they use).

If you plan on using the low power github example in an application that uses the S132 SoftDevice, then you should be aware that the SoftDevice uses the RTC0, and should therefore be enabled. You can see which Hardware peripherals that are used by the SD when it is enabled on this Infocenter page.

Best regards

Bjørn

RE: Migrating SAADC Low Power from SDKv11 to v12

Kevin s — Thu, 03 Nov 2016 02:24:37 GMT

I changed the sdk_config file to "disable" the RTC0 and RTC1...this seems very much a big hack to me. It should be easy to configure this file!
I'm using IAR Workbench so I don't have access to the built-in Kiel editor.

c #ifndef RTC1 ENABLED

c #define RTC1 ENABLED 0

c #ifndef RTC_DEFAULT_CONFIG_FREQUENCY

c #define RTC_DEFAULT_CONFIG_FREQUENCY 32 //32768