nRF52 Zephyr VSCode DeviceTree

[Basri Kilic]

Hello everyone. I've started coding with Zephyr on my nRF52 device. I'm relatively new to this. I'm trying to drive a DC motor with L298N. However, I have no idea how to configure the pin settings in the device tree. I have defined the motor pins in the device tree, but when I try to use them in main.c, I get an error saying they are not defined. Can someone help me understand how to use the device tree? Thank you.

[Basri Kilic]

I am using the nRF52832 microcontroller and the SDK version 2.3.0.

[Øivind]

Ok, I found a few extra issues.

Try this overlay instead:

/ {
    aliases {
        motor-pwm = &motor_pwm0;
        motor-en = &motor_en;
        motor-in1 = &motor_in1;
        motor-in2 = &motor_in2;
    };
    
    motor_pwm {
        compatible = "pwm-leds";
        motor_pwm0: motor_pwm0 {
    		pwms = <&pwm0 0 PWM_MSEC(10) 0>;
    		status = "okay";
    	};
    };
	
	motor_gpios {
	    compatible = "gpio-keys";
    	motor_en: motor_en {
    		gpios = <&gpio0 7 GPIO_ACTIVE_HIGH>;
    		
    	};
    	
    	motor_in1: motor_in1 {
    		gpios = <&gpio0 6 GPIO_ACTIVE_HIGH>;
    		
    	};
    	
    	motor_in2: motor_in2 {
    		gpios = <&gpio0 8 GPIO_ACTIVE_HIGH>;
    	
    	};
    };
};

&pwm_led0 {
	status = "disabled";
};

It also seems that you are using some outdated functions in your code. Read this section of the version 2.x.x migration guide:

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.3.0/nrf/migration/migration_guide_1.x_to_2.x.html#changes-in-pwm-api

You may also want to take a look at the samples at:

zephyr/samples/basic/blinky_pwm
zephyr/samples/basic/button

to see examples of code for pwm-leds and gpio-keys.

[Basri Kilic]

Thank you. I made some changes to the code.But now I'm getting a different error. What could be the cause of this error?

#include <zephyr/kernel.h>
#include <zephyr/sys/printk.h>
#include <zephyr/device.h>
#include <zephyr/drivers/pwm.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/devicetree/gpio.h>
#include <zephyr/devicetree/pwms.h>

#define PWM_PERIOD_USEC 2000

#define ENA_PIN DEVICE_DT_GET(motor_en)
#define IN1_PIN DEVICE_DT_GET(motor_in1)
#define IN2_PIN DEVICE_DT_GET(motor_in2)

#define PWM_DEV PWM_DT_SPEC_GET(motor_pwm0)
#define PWM_CHANNEL DEVICE_DT_GET(motor_pwm0)

#define MOTOR_SPEED_MIN -100
#define MOTOR_SPEED_MAX 100

void main(void)
{
    struct device *pwm_dev , *ena_dev, *in1_dev, *in2_dev;
    int motor_speed = 0;

    pwm_dev = device_get_binding DEVICE_DT_GET(motor_pwm0);
    if (!pwm_dev) {
        printk("Failed to open PWM device\n");
        return;
    }


    ena_dev = device_get_binding DEVICE_DT_GET	(motor_en);
    in1_dev = device_get_binding DEVICE_DT_GET	(motor_in1);
    in2_dev = device_get_binding DEVICE_DT_GET	(motor_in2);
    if (!ena_dev || !in1_dev || !in2_dev) {
        printk("Failed to open GPIO devices\n");
        return;
    }

    
    if (pwm_pin_set_usec(pwm_dev, PWM_CHANNEL, PWM_PERIOD_USEC, 0) < 0) {
        printk("Failed to configure PWM period\n");
        return;
    }

    if (pwm_pin_set_usec(pwm_dev, PWM_CHANNEL, PWM_PERIOD_USEC, 0) < 0) {
        printk("Failed to configure PWM duty cycle\n");
        return;
    }

    if (gpio_pin_configure(ena_dev, ENA_PIN, GPIO_OUTPUT_ACTIVE | GPIO_OUTPUT) < 0) {
        printk("Failed to configure ENA pin\n");
        return;
    }
    if (gpio_pin_configure(in1_dev, IN1_PIN, GPIO_OUTPUT_ACTIVE | GPIO_OUTPUT) < 0) {
        printk("Failed to configure IN1 pin\n");
        return;
    }
    if (gpio_pin_configure(in2_dev, IN2_PIN, GPIO_OUTPUT_ACTIVE | GPIO_OUTPUT) < 0) {
        printk("Failed to configure IN2 pin\n");
        return;
    }

    while (1) {

        motor_speed = clamp(motor_speed, MOTOR_SPEED_MIN, MOTOR_SPEED_MAX);

        uint32_t pwm_duty = map(motor_speed, MOTOR_SPEED_MIN, MOTOR_SPEED_MAX, 0, PWM_PERIOD_USEC);
        if (pwm_pin_set_usec(pwm_dev, PWM_CHANNEL, PWM_PERIOD_USEC, pwm_duty) < 0) {
            printk("Failed to set PWM duty cycle\n");
            return;
        }

        if (motor_speed > 0) {
            gpio_pin_set(ena_dev, ENA_PIN, 1);
            gpio_pin_set(in1_dev, IN1_PIN, 1);
            gpio_pin_set(in2_dev, IN2_PIN, 0);
        } else if (motor_speed < 0) {
            gpio_pin_set(ena_dev, ENA_PIN, 1);
            gpio_pin_set(in1_dev, IN1_PIN, 0);
            gpio_pin_set(in2_dev, IN2_PIN, 1);
        } else {
            gpio_pin_set(ena_dev, ENA_PIN, 0);
            gpio_pin_set(in1_dev, IN1_PIN, 0);
            gpio_pin_set(in2_dev, IN2_PIN, 0);
        }

        k_sleep(K_MSEC(100));
    }
}

[Øivind]

Try this:

#include <zephyr/kernel.h>
#include <zephyr/sys/printk.h>
#include <zephyr/device.h>
#include <zephyr/drivers/pwm.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/devicetree/gpio.h>
#include <zephyr/devicetree/pwms.h>

#define PWM_PERIOD_USEC 2000

static const struct gpio_dt_spec ena_dev = GPIO_DT_SPEC_GET_OR(DT_ALIAS(motor_en), gpios, {0});
static const struct gpio_dt_spec in1_dev = GPIO_DT_SPEC_GET_OR(DT_ALIAS(motor_in1), gpios, {0});
static const struct gpio_dt_spec in2_dev = GPIO_DT_SPEC_GET_OR(DT_ALIAS(motor_in2), gpios, {0});

static const struct pwm_dt_spec pwm_dev = PWM_DT_SPEC_GET(DT_ALIAS(motor_pwm0));

//#define ENA_PIN DEVICE_DT_GET(motor_en)
//#define IN1_PIN DEVICE_DT_GET(motor_in1)
//#define IN2_PIN DEVICE_DT_GET(motor_in2)

//#define PWM_DEV PWM_DT_SPEC_GET(motor_pwm0)
//#define PWM_CHANNEL DEVICE_DT_GET(motor_pwm0)

#define MOTOR_SPEED_MIN -100
#define MOTOR_SPEED_MAX 100

void main(void)
{
    //struct device *pwm_dev , *ena_dev, *in1_dev, *in2_dev;
    int motor_speed = 0;

	if (!device_is_ready(pwm_dev.dev)) {
		printk("Error: PWM device %s is not ready\n",
		       pwm_dev.dev->name);
		return;
	}

	if (!device_is_ready(ena_dev.port) || !device_is_ready(in1_dev.port) 
		|| !device_is_ready(in2_dev.port)) {
		printk("Error: gpio device %s is not ready\n",
		       ena_dev.port->name);
		return;
	}

    //pwm_dev = device_get_binding DEVICE_DT_GET(motor_pwm0);
    //if (!pwm_dev) {
    //    printk("Failed to open PWM device\n");
    //    return;
    //}


    //ena_dev = device_get_binding DEVICE_DT_GET	(motor_en);
    //in1_dev = device_get_binding DEVICE_DT_GET	(motor_in1);
    //in2_dev = device_get_binding DEVICE_DT_GET	(motor_in2);
    //if (!ena_dev || !in1_dev || !in2_dev) {
    //    printk("Failed to open GPIO devices\n");
    //    return;
    //}

    
    if (pwm_set_dt(&pwm_dev, PWM_PERIOD_USEC, 0) < 0) {
        printk("Failed to configure PWM period\n");
        return;
    }

    if (gpio_pin_configure_dt(&ena_dev, (GPIO_OUTPUT_ACTIVE | GPIO_OUTPUT)) < 0) {
        printk("Failed to configure ENA pin\n");
        return;
    }
    if (gpio_pin_configure_dt(&in1_dev, (GPIO_OUTPUT_ACTIVE | GPIO_OUTPUT)) < 0) {
        printk("Failed to configure IN1 pin\n");
        return;
    }
    if (gpio_pin_configure_dt(&in2_dev, (GPIO_OUTPUT_ACTIVE | GPIO_OUTPUT)) < 0) {
        printk("Failed to configure IN2 pin\n");
        return;
    }

    while (1) {

        motor_speed = clamp(motor_speed, MOTOR_SPEED_MIN, MOTOR_SPEED_MAX);

        uint32_t pwm_duty = map(motor_speed, MOTOR_SPEED_MIN, MOTOR_SPEED_MAX, 0, PWM_PERIOD_USEC);
        if (pwm_set_dt(&pwm_dev, PWM_PERIOD_USEC, pwm_duty) < 0) {
            printk("Failed to set PWM duty cycle\n");
            return;
        }

        if (motor_speed > 0) {
            gpio_pin_set_dt(ena_dev, 1);
            gpio_pin_set_dt(in1_dev, 1);
            gpio_pin_set_dt(in2_dev, 0);
        } else if (motor_speed < 0) {
            gpio_pin_set_dt(ena_dev, 1);
            gpio_pin_set_dt(in1_dev, 0);
            gpio_pin_set_dt(in2_dev, 1);
        } else {
            gpio_pin_set_dt(ena_dev, 0);
            gpio_pin_set_dt(in1_dev, 0);
            gpio_pin_set_dt(in2_dev, 0);
        }

        k_sleep(K_MSEC(100));
    }
}

You can remove the commented out code and rename things as you see fit.

[Basri Kilic]

I changed the code and now the motors are working. Thanks for your help.

#include <zephyr/kernel.h>
#include <zephyr/sys/printk.h>
#include <zephyr/device.h>
#include <zephyr/drivers/pwm.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/devicetree/gpio.h>
#include <zephyr/devicetree/pwms.h>
#include <zephyr/drivers/led.h>



static const struct pwm_dt_spec pwm_led0 = PWM_DT_SPEC_GET(DT_ALIAS(pwm_led0));
static const struct gpio_dt_spec in1_dev = GPIO_DT_SPEC_GET_OR(DT_ALIAS(motor1), gpios, {0});
static const struct gpio_dt_spec in2_dev = GPIO_DT_SPEC_GET_OR(DT_ALIAS(motor2), gpios, {0});
static const struct gpio_dt_spec ena_dev = GPIO_DT_SPEC_GET_OR(DT_ALIAS(motor0), gpios, {0});


#define MIN_PERIOD PWM_SEC(1U) / 128U
#define MAX_PERIOD PWM_SEC(1U)

void main(void)
{
	uint32_t max_period;
	uint32_t period;
	uint8_t dir = 0U;
	int ret;
	int ret1;

  

	printk("PWM-based blinky\n");


	if (gpio_pin_configure_dt(&ena_dev, (GPIO_OUTPUT_ACTIVE | GPIO_OUTPUT)) < 0) {
        printk("Failed to configure ENA pin\n");
        return;
    }
    if (gpio_pin_configure_dt(&in1_dev, (GPIO_OUTPUT_ACTIVE | GPIO_OUTPUT)) < 0) {
        printk("Failed to configure IN1 pin\n");
        return;
    }
    if (gpio_pin_configure_dt(&in2_dev, (GPIO_OUTPUT_ACTIVE | GPIO_OUTPUT)) < 0) {
        printk("Failed to configure IN2 pin\n");
        return;
    }

	if (!device_is_ready(pwm_led0.dev)) {
		printk("Error: PWM device %s is not ready\n",
		       pwm_led0.dev->name);
		return;
	}

	gpio_pin_set_dt(&ena_dev, 1);
    gpio_pin_set_dt(&in1_dev, 1);
    gpio_pin_set_dt(&in2_dev, 0);
	pwm_set_dt(&pwm_led0, MIN_PERIOD, MIN_PERIOD / 2U);
	

}