how to close spi in low power state? (52840)

[logly]

Dear, I'm developing on nordic 52840 with ncs2.6.1. 

I found that the Current will reach to 600+uA in k_sleep state by enable SPI in device_tree and if i disable the spi, the current will increase to 100uA.

I have try to enable CONFIG_PM_DEVICE(As far as i know that CONFIG_PM is not support by nrf52840 in ncs2.6.1) and call the function 

pm_device_action_run(spi1_dev, PM_DEVICE_ACTION_SUSPEND)

before k_sleep, but there is no difference in the results。

here is my dts config:(i have removed spi0 which was used by twi0)

&spi1 {
	compatible = "nordic,nrf-spim";
	status = "okay";
	pinctrl-0 = <&spi1_default>;
	pinctrl-1 = <&spi1_sleep>;
	pinctrl-names = "default", "sleep";
	cs-gpios = <&gpio0 14 GPIO_ACTIVE_LOW>, <&gpio0 17 GPIO_ACTIVE_LOW>;
	imu: imu@0 {
		compatible = "imu";
		lable = "imu";
		reg = <0>;
	};
	sdcard: sdcard@1 {
		compatible = "sdcard";
		reg = <1>;
		lable = "sdcard";
	};

	status = "okay";
};

and the main() function is just call a k_sleep without doing anything else.

[Marted]

In your application, before calling k_sleep(), explicitly disable the SPI interface using the spi_release() function.
This will ensure that the SPI interface is not active and consuming power during the low-power state.
Here's an example of how you can do this:

#include <device.h>
#include <drivers/spi.h>

void main(void)
{
const struct device *spi_dev = DEVICE_DT_GET(DT_NODELABEL(spi0));

while (1) {
/* Disable the SPI interface */
spi_release(spi_dev);

/* Enter low-power state */
k_sleep(K_SECONDS(5));

/* Re-enable the SPI interface when needed */
// spi_configure(spi_dev, ...);
// spi_transceive(spi_dev, ...);
}
}

Edited by slope 1 day ago

[Angela4]

You can use Low Power Modes:
Here is a simple example that demonstrates closing the SPI and entering a low power state:

#include "nrf_gpio.h"
#include "nrf_spi.h"
#include "nrf_power.h"

void close_spi_low_power(void) {
// Disable SPI
NRF_SPI0->ENABLE = SPI_ENABLE_ENABLE_Disabled << SPI_ENABLE_ENABLE_Pos;

Edited by slope game 1 day ago

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