NCS v2.4.0: low power by example

RE: NCS v2.4.0: low power by example

Håkon Alseth — Fri, 19 Apr 2024 14:15:55 GMT

Hi,

If you have a specific problem, I would recommend that you create a dedicated thread on the topic and please share as much information as you can wrt. what the problem is and how your application is configured.

GPIO Input vs. output does not do anything wrt. power consumption in this scenario. The only thing that is required is that you pull the signal to a defined level, per the action that is performed.

CSN pin is handled by spi.h/spi_context.h:

https://github.com/nrfconnect/sdk-zephyr/blob/v3.5.99-ncs1/drivers/spi/spi_context.h#L257

Kind regards,

Håkon

RE: NCS v2.4.0: low power by example

Miguel Ferreira — Fri, 19 Apr 2024 14:06:22 GMT

Hi,

Can you point me in the code where this is done ? Also to give more context why Im asking putting CS pin as input is due to power consumption, which I believe as input it will consume less. Or as GPIO_OUTPUT_INACTIVE will consume the same more less ?

RE: NCS v2.4.0: low power by example

Håkon Alseth — Fri, 19 Apr 2024 13:52:36 GMT

Hi,

No, it is always set to an inactive state after a transaction.

Kind regards,

Håkon

RE: NCS v2.4.0: low power by example

Miguel Ferreira — Fri, 19 Apr 2024 13:47:06 GMT

Thanks! Just to clarify, so before entering "sleep" while in SPIM mode I would need to set my CS gpio as input manually ?

RE: NCS v2.4.0: low power by example

Håkon Alseth — Fri, 19 Apr 2024 13:40:12 GMT

That's correct. CSN is kept inactive, and is handled as a normal gpio by the spi.h API.

If you need to set this to a specific state, for instance if you're powering off the external sensor, it has to be done as a part of your firmware routine for powering on/off the specific sensor.

Kind regards,

Håkon

RE: NCS v2.4.0: low power by example

Miguel Ferreira — Fri, 19 Apr 2024 13:14:28 GMT

Correct, but for example de SS pin is not changed to input because we are skipping the gpio_cfg. I debug the code since the point you mentioned and the nrf_gpio_cfg_default is always skipped. Am I correct ?

Also:

#if defined(NRF_PSEL_SPIM)
 case NRF_FUN_SPIM_SCK:
 NRF_PSEL_SPIM(reg, SCK) = pin;
 write = 0U;
 dir = NRF_GPIO_PIN_DIR_OUTPUT;
 input = NRF_GPIO_PIN_INPUT_CONNECT;
 break;
 case NRF_FUN_SPIM_MOSI:
 NRF_PSEL_SPIM(reg, MOSI) = pin;
 write = 0U;
 dir = NRF_GPIO_PIN_DIR_OUTPUT;
 input = NRF_GPIO_PIN_INPUT_DISCONNECT;
 break;
 case NRF_FUN_SPIM_MISO:
 NRF_PSEL_SPIM(reg, MISO) = pin;
 dir = NRF_GPIO_PIN_DIR_INPUT;
 input = NRF_GPIO_PIN_INPUT_CONNECT;
 break;
#endif /* defined(NRF_PSEL_SPIM) */

I dont see the CS pin being changed here

RE: NCS v2.4.0: low power by example

Håkon Alseth — Fri, 19 Apr 2024 12:05:25 GMT

Hi,

pinctrl takes over and configures the state based on your DT configuration:

https://github.com/nrfconnect/sdk-zephyr/blob/v3.5.99-ncs1/drivers/spi/spi_nrfx_spim.c#L546-L557

CSN is kept inactive (effectively handled as a normal gpio output, controlled by the spi.h API), and not touched by the devicetree.

Kind regards,

Håkon

RE: NCS v2.4.0: low power by example

Miguel Ferreira — Fri, 19 Apr 2024 10:17:45 GMT

Hi,

Sorry to jump in a old issue but I have some doubts also regarding pm_device_action_run(m_spi_dev, PM_DEVICE_ACTION_SUSPEND) on spi device. Basically, when entering in suspend the SPI driver should configure the CS pin but this config is being skipped:

Where the default config is:

RF_STATIC_INLINE void nrf_gpio_cfg_default(uint32_t pin_number)
{
 nrf_gpio_cfg(
 pin_number,
 NRF_GPIO_PIN_DIR_INPUT,
 NRF_GPIO_PIN_INPUT_DISCONNECT,
 NRF_GPIO_PIN_NOPULL,
 NRF_GPIO_PIN_S0S1,
 NRF_GPIO_PIN_NOSENSE);

How can I config the CS pin without the driver skipping it ?

Thank you!

RE: NCS v2.4.0: low power by example

Håkon Alseth — Thu, 06 Jul 2023 12:12:26 GMT

Hi.

CLK and MOSI should be set as output, low, when you have placed the device in PM_DEVICE_ACTION_SUSPEND:

https://github.com/nrfconnect/sdk-zephyr/blob/v3.3.99-ncs1/drivers/pinctrl/pinctrl_nrf.c#L122C1-L140

MISO is input to the nRF, which'll be low when your external device is powered off.

Are you seeing that the pins are high in the _SUSPEND state?

Kind regards,

Håkon

RE: NCS v2.4.0: low power by example

pzuck — Wed, 05 Jul 2023 18:15:55 GMT

Hi Hakon,

I would need to call nrf_gpio_pin_clear() to put low also the signals CLK,MISO,MOSI. Then remove the modification I made in "spi_nrfx_spi.c".

How can I get CLK,MISO,MOSI pin numbers like what you made for CS with "DT_SPI_DEV_CS_GPIOS_PIN(DT_NODELABEL(spi0_cs))" ?

thank you, Paolo

RE: NCS v2.4.0: low power by example

Håkon Alseth — Wed, 05 Jul 2023 08:35:48 GMT

Hi,

The idle level of /CSN is high. If you power off your external sensor, you need to set that pin low to ensure that you're not back-powering your external sensor.

Here's a way to set/clr the GPIO:

#include <hal/nrf_gpio.h>


...
nrf_gpio_pin_clear(DT_SPI_DEV_CS_GPIOS_PIN(DT_NODELABEL(spi0_cs)));
pm_device_action_run(spi_dev, PM_DEVICE_ACTION_SUSPEND);
...
nrf_gpio_pin_set(DT_SPI_DEV_CS_GPIOS_PIN(DT_NODELABEL(spi0_cs)));
pm_device_action_run(spi_dev, PM_DEVICE_ACTION_RESUME);

Kind regards,

Håkon

RE: NCS v2.4.0: low power by example

pzuck — Wed, 05 Jul 2023 07:57:11 GMT

Hi Hakon,

In your scope screenshot I don't see /CSN going low for 1 sec by the call:

pm_device_action_run(spi_dev, PM_DEVICE_ACTION_SUSPEND);

therefore the sensor (virtual in your scenario) will never turn OFF.

If everything worked we should see two times CS hi-low-hi transaction. The first very short as SPI read from sensor, the second with a duration of 1000 ms

Let me know

thank you, Paolo

RE: NCS v2.4.0: low power by example

Håkon Alseth — Wed, 05 Jul 2023 07:30:29 GMT

Hi Paulo,

Regarding the .ss_pin member: there is a difference on how the module(s) work at boot-time vs. how they work when actually used.

On boot-up, it will skip the gpio configuration, while when addressed and used in main.c, the configuration will be passed to the spi_nrfx_spi.c and be configured on each run.

As the SPI hardware peripheral does not have a dedicated /CSN pin, this is handled by the gpio driver.

Here's the minimal main.c (based on your code):

/*
 * Copyright (c) 2012-2014 Wind River Systems, Inc.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/logging/log.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/spi.h>
#include <zephyr/pm/device.h>

LOG_MODULE_REGISTER(app);

#define SPI_BUF_SIZE 16
#define MY_SPI_NODE spi0

static const struct device *spi_dev = DEVICE_DT_GET(DT_NODELABEL(MY_SPI_NODE));
static const struct spi_cs_control spi_cs_ctrl = {
	.gpio = GPIO_DT_SPEC_GET(DT_NODELABEL(MY_SPI_NODE), cs_gpios),
	.delay = 2
};

static const struct spi_config spi_cfg = {
	.frequency = 8 * 1000 * 1000,
	.operation = SPI_WORD_SET(8),
	.cs = &spi_cs_ctrl
};

static uint8_t tx_buf[SPI_BUF_SIZE];
static uint8_t rx_buf[SPI_BUF_SIZE];

static struct spi_buf tx_spi_bufs[] = {
	{
		.len = 4,
		.buf = tx_buf
	}
};

static struct spi_buf rx_spi_bufs[] = {
	{
		.len = 4,
		.buf = rx_buf
	}
};

static const struct spi_buf_set	spi_tx_buf_set = {
	.buffers = tx_spi_bufs,
	.count = 1
};

static const struct spi_buf_set	spi_rx_buf_set = {
	.buffers = rx_spi_bufs,
	.count = 1
};

uint8_t test_spi_read(uint8_t addr, uint8_t len)
{
	__ASSERT_NO_MSG(len < SPI_BUF_SIZE);

	tx_buf[0] = addr | BIT(7);

	tx_spi_bufs[0].len = rx_spi_bufs[0].len = len;

	int err = spi_transceive(spi_dev, &spi_cfg, &spi_tx_buf_set, &spi_rx_buf_set);
	if (err < 0)
	{
		LOG_WRN("transceive() failed! err=%d", err);
		return 1;
	} else {
		LOG_INF("OK");
	}
	return 0;
}

int main(void)
{
	printk("Hello World! %s\n", CONFIG_BOARD);
	while (1) {
		test_spi_read(0, 2);
		/* Keep it active for testing purposes */
		k_msleep(1000);
		pm_device_action_run(spi_dev, PM_DEVICE_ACTION_SUSPEND);
		k_msleep(1000);
		pm_device_action_run(spi_dev, PM_DEVICE_ACTION_RESUME);
		k_msleep(1);
	}
}

Here's a scope of the SPI communication on &spi0 (P0.26/P0.27/P0.28, CSN=P0.13):

And here's the overlay that I used:

&spi0 {
        //compatible = "nordic,nrf-spi";
        status = "okay";
        // cs-gpios = <&gpio0 18 GPIO_ACTIVE_LOW>;
        cs-gpios = <&gpio0 13 GPIO_ACTIVE_LOW>;
        spi0_cs: spi0_cs@0 {
                reg = <0>;
        };
};

As I do not have any sensor connected on the SPI bus, there's no response on MISO.

And here's the power consumption:

[quote user="pzuck"]Indeed, when I cut the power to the sensor, it remains powered from /CSN, until I set /CSN to low.[/quote]

This is as intended. If you are powering off your external sensor, you need to ensure that all GPIOs/signals going to your external sensor are kept at GND level.

Kind regards,

Håkon

RE: NCS v2.4.0: low power by example

pzuck — Tue, 04 Jul 2023 16:34:23 GMT

Hi Hakon,

What's happen is clear to me as I followed the code step by step with the debugger and checked the pin states with an oscilloscope.

I can confirm also that the sensor communications over SPI are OK, just I wanted to turn it OFF by using pm_device_action_run(...SUSPEND).

Can't understand why you don't want to get the evidences reported and answer properly.

thank you, Paolo

RE: NCS v2.4.0: low power by example

Håkon Alseth — Tue, 04 Jul 2023 07:02:27 GMT

[quote user="pzuck"]Please have a look at the Zephyr sources, in particolar "spi_nrfx_spi.c" where the field "skip_gpio_cfg" is initialized to TRUE: this initialization prevent any PIN re-configuration from pm_device_action_run(SUSPEND).[/quote]

It is setup this way on purpose, and allows the module/driver that uses it to configure it on-the-fly.

I would strongly recommend that you use a logic analyzer or a oscilloscope to verify the pin states.

[quote user="pzuck"]Furthermore, why the field .ss_csn is not loaded with the correct pin value ?[/quote]

It highly likely is, just at a later point in time.

Kind regards,

Håkon

RE: NCS v2.4.0: low power by example

pzuck — Mon, 03 Jul 2023 17:03:33 GMT

Hi,

I wouldn't change Zephyr code but is quite clear that without those changes the pm_device_action_run(SUSPEND) doesn't handle /CSN as spi_transceive() instead does.

Indeed, when I cut the power to the sensor, it remains powered from /CSN, until I set /CSN to low.

Please have a look at the Zephyr sources, in particolar "spi_nrfx_spi.c" where the field "skip_gpio_cfg" is initialized to TRUE: this initialization prevent any PIN re-configuration from pm_device_action_run(SUSPEND).

Do you have an idea of why that hard-coded initialization ?

Furthermore, why the field .ss_csn is not loaded with the correct pin value ?

Everything seems to be strange, I'm worried about the possibility to have made a mistake somewhere in the configuration files.

thank you, Paolo

RE: NCS v2.4.0: low power by example

Håkon Alseth — Mon, 03 Jul 2023 14:44:04 GMT

Hi,

You are changing things you should not change now.

The SPI module handles the /CS pin on demand. Scope the SPI pins instead (or check the NRF_SPI0 register content after running).

[quote user="pzuck"]

doesn't handle CSN pin because the field that should contain its value reports 255 (NRFX_SPI_PIN_NOT_USED).

[/quote]

/CSN pin only goes active when you try to send data. Please note that it is setup as active low, ie. inactive high.

[quote user="pzuck"]then turns OFF the sensor in an infinite loop.[/quote]

Do you also cut power to the sensor? If yes, then you need to set all GPIOs that is connected to it to a low level.

Kind regards,

Håkon

RE: NCS v2.4.0: low power by example

pzuck — Fri, 30 Jun 2023 14:50:22 GMT

Forgot to notice another modify I've done in "spi_nrfx_spi.c" as follows:

RE: NCS v2.4.0: low power by example

pzuck — Fri, 30 Jun 2023 14:29:25 GMT

Hello Hakon,

I switched to nRF52-DK to which I've manually connected the MEMS sensor over SPI and I can confirm very few microAmp when such sensor is powered OFF.

In order to share something common I still working with sources from "blinky" example (pls find attached).

Such example turns ON the sensor, then successfuly reads its ID, then turns OFF the sensor in an infinite loop. Unfortunately the sensor doesn't turn OFF because of back-driving from CSN pin, indeed I realized that the call to:

pm_device_action_run(mems_spi_dev, PM_DEVICE_ACTION_SUSPEND);

doesn't handle CSN pin because the field that should contain its value reports 255 (NRFX_SPI_PIN_NOT_USED).

CLK, MISO and MOSI are handled correctly, instead.

As a proof and just to test, if I modified the zephyr original source code in "nrfx_spi.c" as follows and at last the sensor turned OFF successfully.

Can you please help me on this ?

The CSN must be initially configured as the sensor ID is read successfully, so what am I missing ?

thank you very much in advance, Paolo

main.c

/*
 * Copyright (c) 2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(app);

#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/spi.h>
#include <zephyr/pm/device.h>
#include <nrfx_spi.h>


#define OFF 					0
#define ON						1

#define LIS2DW12_WHO_AM_I	0x0F
#define LIS2DW12_CTRL2		0x21
#define LIS2DW12_ID			0x44
#define MEMS_BOOTUP_MS		(20+20)	// 20ms boot-up (rif.AN5038 pag.34)


#define SPI_NODE(idx)					DT_NODELABEL(spi##idx)
#define SPI_CS_NODE(idx)				DT_NODELABEL(spi##idx##_cs)


// MEMS
static const struct device 			*mems_spi_dev = DEVICE_DT_GET(SPI_NODE(0));
static const struct spi_cs_control	mems_spi_cs_ctrl = {
	.gpio = SPI_CS_GPIOS_DT_SPEC_GET(SPI_CS_NODE(0)),
	.delay = 2
};

static const struct spi_config 		mems_spi_cfg = {
	.frequency = 8 * 1000 * 1000,	// 8MHZ
	.operation = SPI_WORD_SET(8),
	.cs = &mems_spi_cs_ctrl
};

#define GPIO0_NODE						DT_NODELABEL(gpio0)
static const struct device				*gpio0_dev = DEVICE_DT_GET(GPIO0_NODE);

#define MEMS_PWR_NODE					DT_NODELABEL(mems_pwr)
static const struct gpio_dt_spec 	mems_pwr_spec =
	GPIO_DT_SPEC_GET(MEMS_PWR_NODE, gpios);


#define SPI_BUF_SIZE						256
static uint8_t								tx_buf[SPI_BUF_SIZE];
static uint8_t								rx_buf[SPI_BUF_SIZE];

static struct spi_buf 					tx_spi_bufs[] = {
	{
		.buf = tx_buf
	}
};

static struct spi_buf 					rx_spi_bufs[] = {
	{
		.buf = rx_buf
	}
};

static const struct spi_buf_set 		spi_tx_buf_set = {
	.buffers = tx_spi_bufs,
	.count = 1
};

static const struct spi_buf_set 		spi_rx_buf_set = {
	.buffers = rx_spi_bufs,
	.count = 1
};

#define TX_RX_MSG_LENGTH				256
static uint8_t								m_tx_data_spi[TX_RX_MSG_LENGTH]; ///< SPI TX buffer.


uint8_t mems_power(uint8_t p)
{
	if (p)
	{
		gpio_pin_configure_dt(&mems_pwr_spec, GPIO_OUTPUT);
		gpio_pin_set_dt(&mems_pwr_spec, ON);
	}
	else
	{
		// gpio_pin_configure_dt(&mems_pwr_spec, GPIO_INPUT);
		gpio_pin_configure_dt(&mems_pwr_spec, GPIO_OUTPUT);
		gpio_pin_set_dt(&mems_pwr_spec, OFF);
	}

	k_msleep(MEMS_BOOTUP_MS);

	return 0;	// OK
}

uint8_t mems_spi_read(uint8_t addr, void *val, uint8_t len)
{
	__ASSERT_NO_MSG(len < SPI_BUF_SIZE);

	tx_buf[0] = addr | BIT(7);

	tx_spi_bufs[0].len =
	rx_spi_bufs[0].len = 1+len;

	int err = spi_transceive(mems_spi_dev, &mems_spi_cfg,
									 &spi_tx_buf_set, &spi_rx_buf_set);
	if (err < 0)
	{
		LOG_WRN("transceive() failed! err=%d", err);
		return 1;	// KO
	}

	//LOG_HEXDUMP_DBG(rx_buf, 1+len, "rx");
	memcpy(val, rx_buf+1, len);

	return 0;	// OK
}

void mems_check_id(void)
{
	char buf[4];

	mems_spi_read(LIS2DW12_WHO_AM_I, buf, 1);
	LOG_INF("mems_check: id=x%X/x%X", *buf, LIS2DW12_ID);
}

int spi_init(void)
{
	if (!device_is_ready(mems_spi_dev))
		return 1;

	return 0;
}

int main(void)
{
	while (1)
	{
		mems_power(ON);
		k_msleep(1000);

		mems_check_id();
		k_msleep(1000);

		mems_power(OFF);
		k_msleep(1000);

		pm_device_action_run(mems_spi_dev, PM_DEVICE_ACTION_SUSPEND);
		k_msleep(1000);
	}

	return 0;
}

board.overlay

// To get started, press Ctrl+Space to bring up the completion menu and view the available nodes.

// You can also use the buttons in the sidebar to perform actions on nodes.
// Actions currently available include:

// * Enabling / disabling the node
// * Adding the bus to a bus
// * Removing the node
// * Connecting ADC channels

// For more help, browse the DeviceTree documentation at https://docs.zephyrproject.org/latest/guides/dts/index.html
// You can also visit the nRF DeviceTree extension documentation at https://nrfconnect.github.io/vscode-nrf-connect/devicetree/nrfdevicetree.html

&sram0 {
	reg = <0x20000000 (DT_SIZE_K(64)-128)>;
};

&pinctrl {
	spi0_default: spi0_default {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 14)>,
				<NRF_PSEL(SPIM_MOSI, 0, 16)>,
				<NRF_PSEL(SPIM_MISO, 0, 15)>;
		};
	};

	spi0_sleep: spi0_sleep {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 14)>,
				<NRF_PSEL(SPIM_MOSI, 0, 16)>,
				<NRF_PSEL(SPIM_MISO, 0, 15)>;
			low-power-enable;
		};
	};

	spi1_default: spi1_default {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 7)>,
				<NRF_PSEL(SPIM_MOSI, 0, 6)>,
				<NRF_PSEL(SPIM_MISO, 0, 3)>;
		};
	};

	spi1_sleep: spi1_sleep {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 7)>,
				<NRF_PSEL(SPIM_MOSI, 0, 6)>,
				<NRF_PSEL(SPIM_MISO, 0, 3)>;
			low-power-enable;
		};
	};
};

&i2c0 {
	status = "disabled";
};

&spi0 {
	//compatible = "nordic,nrf-spi";
	status = "okay";
	// cs-gpios = <&gpio0 18 GPIO_ACTIVE_LOW>;
	cs-gpios = <&gpio0 13 GPIO_ACTIVE_LOW>;
	spi0_cs: spi0_cs@0 {
		reg = <0>;
	};
};

&spi1 {
	//compatible = "nordic,nrf-spi";
	cs-gpios = <&gpio0 2 GPIO_ACTIVE_LOW>;
	spi1_cs: spi1_cs@0 {
		reg = <0>;
	};
};

&spi2 {
	status = "disabled";
};

&uart0 {
	status = "disabled";
};

&arduino_serial {
	status = "disabled";
};

&arduino_spi {
	status = "disabled";
};

&arduino_i2c {
	status = "disabled";
};

&pwm0 {
	status = "disabled";
};

&led0 {
	status = "disabled";
};

&led1 {
	status = "disabled";
};

&led2 {
	status = "disabled";
};

&led3 {
	status = "disabled";
};

&pwm_led0 {
	status = "disabled";
};

&button0 {
	status = "disabled";
};

&button1 {
	status = "disabled";
};

&button2 {
	status = "disabled";
};

&button3 {
	status = "disabled";
};

/ {
	ingressi {
		compatible = "gpio-keys";
		button: button {
			gpios = <&gpio0 11 GPIO_ACTIVE_HIGH>;
		};
		mems_int: mems_int {
			gpios = <&gpio0 14 GPIO_ACTIVE_HIGH>;
		};
	};
};

/ {
	uscite {
		compatible = "gpio-leds";
		led_red: led_red {
			gpios = <&gpio0 24 GPIO_ACTIVE_LOW>;
		};
		led_green: led_green {
			gpios = <&gpio0 22 GPIO_ACTIVE_LOW>;
		};
		led_blue: led_blue {
			gpios = <&gpio0 23 GPIO_ACTIVE_LOW>;
		};
  		mems_pwr: mems_pwr {
  			gpios = <&gpio0 12 GPIO_ACTIVE_HIGH>;
		};
		extm_pwr: extm_pwr {
			gpios = <&gpio0 8 GPIO_ACTIVE_LOW>;
		};
		extm_rst: extm_rst {
			gpios = <&gpio0 5 GPIO_ACTIVE_LOW>;
		};
		extm_wp: extm_wp {
			gpios = <&gpio0 4 GPIO_ACTIVE_LOW>;
		};
		adc_vbatt: adc_vbatt {
			gpios = <&gpio0 30 GPIO_ACTIVE_LOW>;
		};
	};
};

// MCU boot single slot configuration
// /delete-node/ &boot_partition;
// /delete-node/ &slot0_partition;
// /delete-node/ &slot1_partition;

// &flash0 {
// 	partitions {
// 			compatible = "fixed-partitions";
// 			#address-cells = <1>;
// 			#size-cells = <1>;

// 			boot_partition: partition@0 {
// 				label = "mcuboot";
// 				reg = <0x000000000 0x0000c000>;
// 			};
// 			slot0_partition: partition@c000 {
// 				label = "image-0";
// 				reg = <0x00000c000 0x00006e000>;
// 			};
// 	};
// };

board.dts

/*
 * Copyright (c) 2017 Shawn Nock <shawn@monadnock.ca>
 * Copyright (c) 2017 Linaro Limited
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/dts-v1/;
#include <nordic/nrf52832_qfaa.dtsi>
#include "nrf52dk_nrf52832-pinctrl.dtsi"

/ {
	model = "Nordic nRF52 DK NRF52832";
	compatible = "nordic,nrf52-dk-nrf52832";

	chosen {
		zephyr,console = &uart0;
		zephyr,shell-uart = &uart0;
		zephyr,uart-mcumgr = &uart0;
		zephyr,bt-mon-uart = &uart0;
		zephyr,bt-c2h-uart = &uart0;
		zephyr,sram = &sram0;
		zephyr,flash = &flash0;
		zephyr,code-partition = &slot0_partition;
	};

	leds {
		compatible = "gpio-leds";
		led0: led_0 {
			gpios = <&gpio0 17 GPIO_ACTIVE_LOW>;
			label = "Green LED 0";
		};
		led1: led_1 {
			gpios = <&gpio0 18 GPIO_ACTIVE_LOW>;
			label = "Green LED 1";
		};
		led2: led_2 {
			gpios = <&gpio0 19 GPIO_ACTIVE_LOW>;
			label = "Green LED 2";
		};
		led3: led_3 {
			gpios = <&gpio0 20 GPIO_ACTIVE_LOW>;
			label = "Green LED 3";
		};
	};

	pwmleds {
		compatible = "pwm-leds";
		pwm_led0: pwm_led_0 {
			pwms = <&pwm0 0 PWM_MSEC(20) PWM_POLARITY_INVERTED>;
		};
	};

	buttons {
		compatible = "gpio-keys";
		button0: button_0 {
			gpios = <&gpio0 13 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
			label = "Push button switch 0";
		};
		button1: button_1 {
			gpios = <&gpio0 14 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
			label = "Push button switch 1";
		};
		button2: button_2 {
			gpios = <&gpio0 15 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
			label = "Push button switch 2";
		};
		button3: button_3 {
			gpios = <&gpio0 16 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
			label = "Push button switch 3";
		};
	};

	arduino_header: connector {
		compatible = "arduino-header-r3";
		#gpio-cells = <2>;
		gpio-map-mask = <0xffffffff 0xffffffc0>;
		gpio-map-pass-thru = <0 0x3f>;
		gpio-map = <0 0 &gpio0 3 0>,	/* A0 */
			   <1 0 &gpio0 4 0>,	/* A1 */
			   <2 0 &gpio0 28 0>,	/* A2 */
			   <3 0 &gpio0 29 0>,	/* A3 */
			   <4 0 &gpio0 30 0>,	/* A4 */
			   <5 0 &gpio0 31 0>,	/* A5 */
			   <6 0 &gpio0 11 0>,	/* D0 */
			   <7 0 &gpio0 12 0>,	/* D1 */
			   <8 0 &gpio0 13 0>,	/* D2 */
			   <9 0 &gpio0 14 0>,	/* D3 */
			   <10 0 &gpio0 15 0>,	/* D4 */
			   <11 0 &gpio0 16 0>,	/* D5 */
			   <12 0 &gpio0 17 0>,	/* D6 */
			   <13 0 &gpio0 18 0>,	/* D7 */
			   <14 0 &gpio0 19 0>,	/* D8 */
			   <15 0 &gpio0 20 0>,	/* D9 */
			   <16 0 &gpio0 22 0>,	/* D10 */
			   <17 0 &gpio0 23 0>,	/* D11 */
			   <18 0 &gpio0 24 0>,	/* D12 */
			   <19 0 &gpio0 25 0>,	/* D13 */
			   <20 0 &gpio0 26 0>,	/* D14 */
			   <21 0 &gpio0 27 0>;	/* D15 */
	};

	arduino_adc: analog-connector {
		compatible = "arduino,uno-adc";
		#io-channel-cells = <1>;
		io-channel-map = <0 &adc 1>,	/* A0 = P0.3 = AIN1 */
				 <1 &adc 2>,	/* A1 = P0.4 = AIN2 */
				 <2 &adc 4>,	/* A2 = P0.28 = AIN4 */
				 <3 &adc 5>,	/* A3 = P0.29 = AIN5 */
				 <4 &adc 6>,	/* A4 = P0.30 = AIN6 */
				 <5 &adc 7>;	/* A5 = P0.31 = AIN7 */
	};

	/* These aliases are provided for compatibility with samples */
	aliases {
		led0 = &led0;
		led1 = &led1;
		led2 = &led2;
		led3 = &led3;
		pwm-led0 = &pwm_led0;
		sw0 = &button0;
		sw1 = &button1;
		sw2 = &button2;
		sw3 = &button3;
		bootloader-led0 = &led0;
		mcuboot-button0 = &button0;
		mcuboot-led0 = &led0;
		watchdog0 = &wdt0;
	};
};

&adc {
	status = "okay";
};

&gpiote {
	status = "okay";
};

&gpio0 {
	status = "okay";
};

arduino_serial: &uart0 {
	status = "okay";
	compatible = "nordic,nrf-uarte";
	current-speed = <115200>;
	pinctrl-0 = <&uart0_default>;
	pinctrl-1 = <&uart0_sleep>;
	pinctrl-names = "default", "sleep";
};

arduino_i2c: &i2c0 {
	compatible = "nordic,nrf-twi";
	status = "okay";
	pinctrl-0 = <&i2c0_default>;
	pinctrl-1 = <&i2c0_sleep>;
	pinctrl-names = "default", "sleep";
};

&i2c1 {
	compatible = "nordic,nrf-twi";
	/* Cannot be used together with spi1. */
	/* status = "okay"; */
	pinctrl-0 = <&i2c1_default>;
	pinctrl-1 = <&i2c1_sleep>;
	pinctrl-names = "default", "sleep";
};

&pwm0 {
	status = "okay";
	pinctrl-0 = <&pwm0_default>;
	pinctrl-1 = <&pwm0_sleep>;
	pinctrl-names = "default", "sleep";
};

&spi0 {
	compatible = "nordic,nrf-spi";
	/* Cannot be used together with i2c0. */
	/* status = "okay"; */
	pinctrl-0 = <&spi0_default>;
	pinctrl-1 = <&spi0_sleep>;
	pinctrl-names = "default", "sleep";
};

&spi1 {
	compatible = "nordic,nrf-spi";
	status = "okay";
	pinctrl-0 = <&spi1_default>;
	pinctrl-1 = <&spi1_sleep>;
	pinctrl-names = "default", "sleep";
};

arduino_spi: &spi2 {
	compatible = "nordic,nrf-spi";
	status = "okay";
	cs-gpios = <&arduino_header 16 GPIO_ACTIVE_LOW>; /* D10 */
	pinctrl-0 = <&spi2_default>;
	pinctrl-1 = <&spi2_sleep>;
	pinctrl-names = "default", "sleep";
};

&flash0 {

	partitions {
		compatible = "fixed-partitions";
		#address-cells = <1>;
		#size-cells = <1>;

		boot_partition: partition@0 {
			label = "mcuboot";
			reg = <0x00000000 0xc000>;
		};
		slot0_partition: partition@c000 {
			label = "image-0";
			reg = <0x0000C000 0x37000>;
		};
		slot1_partition: partition@43000 {
			label = "image-1";
			reg = <0x00043000 0x37000>;
		};
		storage_partition: partition@7a000 {
			label = "storage";
			reg = <0x0007a000 0x00006000>;
		};
	};
};

prj.conf

CONFIG_GPIO=y
CONFIG_SPI=y
CONFIG_ASSERT=y
CONFIG_LOG=y
CONFIG_PM=y
CONFIG_PM_DEVICE=y

RE: NCS v2.4.0: low power by example

Håkon Alseth — Mon, 26 Jun 2023 09:08:44 GMT

Hi Paolo,

Sorry for the late reply.

Due to this errata on nRF52832: https://infocenter.nordicsemi.com/topic/errata_nRF52832_Rev3/ERR/nRF52832/Rev3/latest/anomaly_832_58.html#anomaly_832_58

You must select the configuration: CONFIG_SOC_NRF52832_ALLOW_SPIM_DESPITE_PAN_58=y

You might also need to set: CONFIG_NRFX_PPI=y

Please note that this restriction should only be applied if you are certain that you will not trigger the above mentioned anomaly.

This can also explain why you're not seeing a higher current consumption when selecting "nordic,nrf-spim"; as the above kconfig was blocking you from enabling the SPIx instances.

Even with all of these set at my end (regardless of nrf,spi or nrf,spim used), I still see < 10 uA sleep with your project.

You need to check if the additional current goes into your external flash.

Kind regards,

Håkon

RE: NCS v2.4.0: low power by example

pzuck — Fri, 23 Jun 2023 15:13:05 GMT

Hi Hakon,

Pls confirm if you managed to build without errors, I'm stuck on this point since long time...

thank you, Paolo

RE: NCS v2.4.0: low power by example

pzuck — Fri, 23 Jun 2023 12:33:44 GMT

Hi,

The error persists even if I delete "build" folder. Any other hints ?

As I'm a newbie in Zephyr it would be more effective to figure out the difference between spi & spim in the compatible item...

regard, Paolo

RE: NCS v2.4.0: low power by example

Håkon Alseth — Fri, 23 Jun 2023 11:56:14 GMT

Hi,

Try deleting your build-folder for each time that you change the "compatible" line in the overlay file.

[quote user="pzuck"]I assume that when all related I/O pins are set to HI-Z it shouldn't be backdriven, anyway just to try I've uncommented the line below for &spi0 and &spi1:[/quote]

You have to set the CSN inactive to avoid added consumption from any external IC. If it floats, it can draw excessive current.

Kind regards,

Håkon

RE: NCS v2.4.0: low power by example

pzuck — Fri, 23 Jun 2023 09:53:33 GMT

Hi All,

Trying to make some steps ahead I began to evolve blinky project by initializing some structures aiming to exchange some basic data but unfortunately I got the following error from linker:

d:/programmi/ncs/toolchains/31f4403e35/opt/zephyr-sdk/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.2.0/../../../../arm-zephyr-eabi/bin/ld.bfd.exe: app/libapp.a(main.c.obj): in function `spi_init':
D:\Project\blinky\src\main.c:74: undefined reference to `__device_dts_ord_78'
collect2.exe: error: ld returned 1 exit status

That error arises only when: compatible = "nordic,nrf-spim"; if I replace with: compatible = "nordic,nrf-spi" the error disappears and the build completes successfully.

Anyone can tell me what's missing ?

thank you in advance, Paolo

main.c

/*
 * Copyright (c) 2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/spi.h>

/* 1000 msec = 1 sec */
#define SLEEP_TIME_MS   1000

/* The devicetree node identifier for the "led0" alias. */
#define LED0_NODE DT_NODELABEL(led_red)

/*
 * A build error on this line means your board is unsupported.
 * See the sample documentation for information on how to fix this.
 */
static const struct gpio_dt_spec led = GPIO_DT_SPEC_GET(LED0_NODE, gpios);



// MEMS
#define MEMS_SPI_NODE			DT_NODELABEL(spi0)
static const struct device 	*mems_spi_dev = DEVICE_DT_GET(MEMS_SPI_NODE);

#define MEMS_SPI_CS_NODE		DT_NODELABEL(spi0_cs)
static const struct spi_cs_control mems_spi_cs_ctrl = {
	.gpio = SPI_CS_GPIOS_DT_SPEC_GET(MEMS_SPI_CS_NODE),
	.delay = 2
};

static const struct spi_config mems_spi_cfg = {
	.frequency = 8000000,	// 8MHZ
	.operation = SPI_WORD_SET(8),
	.cs = &mems_spi_cs_ctrl
};

#define	SPI_BUF_SIZE	256
static uint8_t tx_buf[SPI_BUF_SIZE];
static uint8_t rx_buf[SPI_BUF_SIZE];

static struct spi_buf tx_spi_bufs[] = {
	{
		.buf = tx_buf
	}
};

static struct spi_buf rx_spi_bufs[] = {
	{
		.buf = rx_buf
	}
};

static const struct spi_buf_set spi_tx_buf_set = {
	.buffers = tx_spi_bufs,
	.count = 1
};

static const struct spi_buf_set spi_rx_buf_set = {
	.buffers = rx_spi_bufs,
	.count = 1
};


int spi_init(void)
{
	if (!device_is_ready(mems_spi_dev))
		return 1;

	return 0;	// OK
}


int main(void)
{
	if (!gpio_is_ready_dt(&led))
	{
		return 0;
	}

	int ret = gpio_pin_configure_dt(&led, GPIO_OUTPUT_ACTIVE);
	if (ret < 0)
		return 0;

	spi_init();

	while (1) 
	{
		ret = gpio_pin_toggle_dt(&led);
		if (ret < 0)
			return 0;
		
		k_msleep(SLEEP_TIME_MS);
	}
	
	return 0;
}

board.dts

/*
 * Copyright (c) 2017 Shawn Nock <shawn@monadnock.ca>
 * Copyright (c) 2017 Linaro Limited
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/dts-v1/;
#include <nordic/nrf52832_qfaa.dtsi>
#include "nrf52dk_nrf52832-pinctrl.dtsi"

/ {
	model = "Nordic nRF52 DK NRF52832";
	compatible = "nordic,nrf52-dk-nrf52832";

	chosen {
		zephyr,console = &uart0;
		zephyr,shell-uart = &uart0;
		zephyr,uart-mcumgr = &uart0;
		zephyr,bt-mon-uart = &uart0;
		zephyr,bt-c2h-uart = &uart0;
		zephyr,sram = &sram0;
		zephyr,flash = &flash0;
		zephyr,code-partition = &slot0_partition;
	};

	/* These aliases are provided for compatibility with samples */
	aliases {
		// led0 = &led0;
		// led1 = &led1;
		// led2 = &led2;
		// led3 = &led3;
		// pwm-led0 = &pwm_led0;
		// sw0 = &button0;
		// sw1 = &button1;
		// sw2 = &button2;
		// sw3 = &button3;
		// bootloader-led0 = &led0;
		// mcuboot-button0 = &button0;
		// mcuboot-led0 = &led0;
		watchdog0 = &wdt0;
	};
};

&adc {
	status = "okay";
};

&gpiote {
	status = "okay";
};

&gpio0 {
	status = "okay";
};

&pinctrl {
	uart0_default: uart0_default {
		group1 {
			psels = <NRF_PSEL(UART_TX, 0, 20)>,
				<NRF_PSEL(UART_RX, 0, 19)>;
		};
	};

	uart0_sleep: uart0_sleep {
		group1 {
			psels = <NRF_PSEL(UART_TX, 0, 20)>,
				<NRF_PSEL(UART_RX, 0, 19)>;
			low-power-enable;
		};
	};

	spi0_default: spi0_default {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 17)>,
				<NRF_PSEL(SPIM_MOSI, 0, 16)>,
				<NRF_PSEL(SPIM_MISO, 0, 15)>;
		};
	};

	spi0_sleep: spi0_sleep {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 17)>,
				<NRF_PSEL(SPIM_MOSI, 0, 16)>,
				<NRF_PSEL(SPIM_MISO, 0, 15)>;
			low-power-enable;
		};
	};

	spi1_default: spi1_default {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 7)>,
				<NRF_PSEL(SPIM_MOSI, 0, 6)>,
				<NRF_PSEL(SPIM_MISO, 0, 3)>;
		};
	};

	spi1_sleep: spi1_sleep {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 7)>,
				<NRF_PSEL(SPIM_MOSI, 0, 6)>,
				<NRF_PSEL(SPIM_MISO, 0, 3)>;
			low-power-enable;
		};
	};
};

&uart0 {
	status = "okay";
	compatible = "nordic,nrf-uarte";
	current-speed = <115200>;
	pinctrl-0 = <&uart0_default>;
	pinctrl-1 = <&uart0_sleep>;
	pinctrl-names = "default", "sleep";
};

&spi0 {
	compatible = "nordic,nrf-spim";
	status = "okay";
	pinctrl-0 = <&spi0_default>;
	pinctrl-1 = <&spi0_sleep>;
	pinctrl-names = "default", "sleep";
	cs-gpios = <&gpio0 18 GPIO_ACTIVE_LOW>;
	spi0_cs: spi0_cs@0 {
		reg = <0>;
	};
};
	
&spi1 {
	compatible = "nordic,nrf-spim";
	status = "okay";
	pinctrl-0 = <&spi1_default>;
	pinctrl-1 = <&spi1_sleep>;
	pinctrl-names = "default", "sleep";
 	cs-gpios = <&gpio0 2 GPIO_ACTIVE_LOW>;
 	spi1_cs: spi1_cs@0 {
 		reg = <0>;
 	};
};

&flash0 {

	partitions {
		compatible = "fixed-partitions";
		#address-cells = <1>;
		#size-cells = <1>;

		boot_partition: partition@0 {
			label = "mcuboot";
			reg = <0x00000000 0xc000>;
		};
		slot0_partition: partition@c000 {
			label = "image-0";
			reg = <0x0000C000 0x37000>;
		};
		slot1_partition: partition@43000 {
			label = "image-1";
			reg = <0x00043000 0x37000>;
		};
		storage_partition: partition@7a000 {
			label = "storage";
			reg = <0x0007a000 0x00006000>;
		};
	};
};

board.overlay

/ {
	outputs {
		compatible = "gpio-leds";
		led_red: led_red {
			gpios = <&gpio0 24 GPIO_ACTIVE_LOW>;
		};
	};
};

prj.conf

CONFIG_GPIO=y
CONFIG_SPI=y

RE: NCS v2.4.0: low power by example

pzuck — Thu, 22 Jun 2023 13:44:24 GMT

Hi Hakon,

Yes, there is an external SPI flash but I assume that when all related I/O pins are set to HI-Z it shouldn't be backdriven, anyway just to try I've uncommented the line below for &spi0 and &spi1:

compatible = "nordic,nrf-spim";

And magically the extra-current disappeared !!!! How do you explain this?

thank you, Paolo

// compatible = "nordic,nrf-spim";

compatible = "nordic,nrf-spim";

tag.dts

/*
 * Copyright (c) 2017 Shawn Nock <shawn@monadnock.ca>
 * Copyright (c) 2017 Linaro Limited
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/dts-v1/;
#include <nordic/nrf52832_qfaa.dtsi>
#include "nrf52dk_nrf52832-pinctrl.dtsi"

/ {
	model = "Nordic nRF52 DK NRF52832";
	compatible = "nordic,nrf52-dk-nrf52832";

	chosen {
		zephyr,console = &uart0;
		zephyr,shell-uart = &uart0;
		zephyr,uart-mcumgr = &uart0;
		zephyr,bt-mon-uart = &uart0;
		zephyr,bt-c2h-uart = &uart0;
		zephyr,sram = &sram0;
		zephyr,flash = &flash0;
		zephyr,code-partition = &slot0_partition;
	};

	/* These aliases are provided for compatibility with samples */
	aliases {
		// led0 = &led0;
		// led1 = &led1;
		// led2 = &led2;
		// led3 = &led3;
		// pwm-led0 = &pwm_led0;
		// sw0 = &button0;
		// sw1 = &button1;
		// sw2 = &button2;
		// sw3 = &button3;
		// bootloader-led0 = &led0;
		// mcuboot-button0 = &button0;
		// mcuboot-led0 = &led0;
		watchdog0 = &wdt0;
	};
};

&adc {
	status = "okay";
};

&gpiote {
	status = "okay";
};

&gpio0 {
	status = "okay";
};

&uart0 {
	status = "okay";
	compatible = "nordic,nrf-uarte";
	current-speed = <115200>;
	pinctrl-0 = <&uart0_default>;
	pinctrl-1 = <&uart0_sleep>;
	pinctrl-names = "default", "sleep";
};

&pinctrl {
	uart0_default: uart0_default {
		group1 {
			psels = <NRF_PSEL(UART_TX, 0, 20)>,
				<NRF_PSEL(UART_RX, 0, 19)>;
		};
	};

	uart0_sleep: uart0_sleep {
		group1 {
			psels = <NRF_PSEL(UART_TX, 0, 20)>,
				<NRF_PSEL(UART_RX, 0, 19)>;
			low-power-enable;
		};
	};

	spi0_default: spi0_default {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 17)>,
				<NRF_PSEL(SPIM_MOSI, 0, 16)>,
				<NRF_PSEL(SPIM_MISO, 0, 15)>;
		};
	};

	spi0_sleep: spi0_sleep {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 17)>,
				<NRF_PSEL(SPIM_MOSI, 0, 16)>,
				<NRF_PSEL(SPIM_MISO, 0, 15)>;
			low-power-enable;
		};
	};

	spi1_default: spi1_default {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 7)>,
				<NRF_PSEL(SPIM_MOSI, 0, 6)>,
				<NRF_PSEL(SPIM_MISO, 0, 3)>;
		};
	};

	spi1_sleep: spi1_sleep {
		group1 {
			psels = <NRF_PSEL(SPIM_SCK, 0, 7)>,
				<NRF_PSEL(SPIM_MOSI, 0, 6)>,
				<NRF_PSEL(SPIM_MISO, 0, 3)>;
			low-power-enable;
		};
	};
};

&spi0 {
	compatible = "nordic,nrf-spim";
	status = "okay";
	pinctrl-0 = <&spi0_default>;
	pinctrl-1 = <&spi0_sleep>;
	pinctrl-names = "default", "sleep";
	cs-gpios = <&gpio0 18 GPIO_ACTIVE_LOW>;
	spi0_cs: spi0_cs@0 {
		reg = <0>;
	};
};
	
&spi1 {
	compatible = "nordic,nrf-spim";
	status = "okay";
	pinctrl-0 = <&spi1_default>;
	pinctrl-1 = <&spi1_sleep>;
	pinctrl-names = "default", "sleep";
 	cs-gpios = <&gpio0 2 GPIO_ACTIVE_LOW>;
 	spi1_cs: spi1_cs@0 {
 		reg = <0>;
 	};
};

&flash0 {

	partitions {
		compatible = "fixed-partitions";
		#address-cells = <1>;
		#size-cells = <1>;

		boot_partition: partition@0 {
			label = "mcuboot";
			reg = <0x00000000 0xc000>;
		};
		slot0_partition: partition@c000 {
			label = "image-0";
			reg = <0x0000C000 0x37000>;
		};
		slot1_partition: partition@43000 {
			label = "image-1";
			reg = <0x00043000 0x37000>;
		};
		storage_partition: partition@7a000 {
			label = "storage";
			reg = <0x0007a000 0x00006000>;
		};
	};
};