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

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

boris bergman1 — Thu, 10 Apr 2025 14:01:02 GMT

Found the cause, the the cs-gpio pin had to be disabled. Now power consumption is 7uA with 5seconds ble advertising interval.

    NRF_P1->PIN_CNF[12] =
        (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos) |
        (GPIO_PIN_CNF_INPUT_Disconnect << GPIO_PIN_CNF_INPUT_Pos) |
        (GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos) |
        (GPIO_PIN_CNF_DRIVE_S0S1 << GPIO_PIN_CNF_DRIVE_Pos) |
        (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos);

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

boris bergman1 — Wed, 09 Apr 2025 16:32:01 GMT

I have the same problem. When I configure spi2 on a xiao rev2 chip disabled, I get low power around 40uA, but enabled it is around 180uA.

&spi2 {    
	status = "okay";
	cs-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;	
	
	gendev: gendev@0 {
		
		compatible = "vnd,spi-device";
		reg = <0>;
		spi-max-frequency = <DT_FREQ_M(1)>;
		
		label = "GenDev";
		status = "okay";
	}; 
};

const struct spi_dt_spec spiDevice = SPI_DT_SPEC_GET(DT_NODELABEL(gendev), SPIOP, 0);

pm_device_action_run(spiDevice.bus, PM_DEVICE_ACTION_SUSPEND);

The above code returns 0, no error, but also no effect.

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

emilyjohnson63 — Tue, 04 Feb 2025 04:19:49 GMT

I think...

Double-Check Support: While you suspect CONFIG_PM_DEVICE isn't fully supported on the nRF52840 in NCS 2.6.1, absolutely confirm this. The Zephyr documentation might have been updated. Check the release notes and the Kconfig files for your specific board/SoC. If it is supported, make sure it's correctly enabled and that the spi1_dev you're passing to pm_device_action_run() is the correct device structure for your SPI1 peripheral. Print its address or name to be certain.
Timing: Ensure pm_device_action_run() is called immediately before k_sleep(). Any code execution between these calls could re-enable the SPI peripheral or prevent it from entering the suspended state.
Return Value: Check the return value of pm_device_action_run(). A non-zero return indicates an error. Print the error code to understand why the suspend operation might be failing. slope

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

Angela4 — Wed, 25 Dec 2024 09:44:29 GMT

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

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

Marted — Tue, 25 Jun 2024 10:20:14 GMT

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