RE: Program to interface Grove Four Digit Display(TM1637) with nRF chips

user115760 — Wed, 15 Jun 2022 05:06:29 GMT

After searching different Questions and Answers in Devzone, I came to the point , that I have to change the Device Tree by including Overlay file in the root folder of the main function. I have made a simple program to blink an LED connected to the GPIO pin 22 which is declared as CLK.

Refernce

Device Tree Overlay Program Reference

I have included the main.c function and the overlay file below:

main.c

#include <zephyr.h>
#include <device.h>
#include <devicetree.h>
#include <drivers/gpio.h>

/* Increase the main thread sleep time from 100ms to 1 second  */
#define SLEEP_TIME_MS 1000


//Defining GPIO pins
#define CLK_NODE DT_ALIAS(gpiocus0)
#if DT_NODE_HAS_STATUS(CLK_NODE, okay)
#define CLK DT_GPIO_LABEL(CLK_NODE, gpios)
#define CLK_PIN DT_GPIO_PIN(CLK_NODE, gpios)
#define CLK_FLAGS DT_GPIO_FLAGS(CLK_NODE, gpios)
#else
#error "Unsupported board: gpio22 devicetree alias is not defined"
#endif

#define DIO_NODE DT_ALIAS(gpiocus1)
#if DT_NODE_HAS_STATUS(DIO_NODE, okay)
#define DIO DT_GPIO_LABEL(DIO_NODE, gpios)
#define DIO_PIN DT_GPIO_PIN(DIO_NODE, gpios)
#define DIO_FLAGS DT_GPIO_FLAGS(DIO_NODE, gpios)
#else
#error "Unsupported board: gpio24 devicetree alias is not defined"
#endif


void main(void)
{
    const struct device *dev;
    bool led_is_on = true;
    int ret;
    
    dev = device_get_binding(CLK);
    if (dev == NULL) 
    {
        return;
    }
    
    ret = gpio_pin_configure(dev, CLK_PIN, GPIO_OUTPUT_ACTIVE | CLK_FLAGS);
    if (ret < 0) 
    {
        return;
    }

    while (1) 
    {
        gpio_pin_set(dev, CLK_PIN, (int)led_is_on);
        led_is_on = !led_is_on;
        k_msleep(SLEEP_TIME_MS);
    }
}

Device tree overlay file:

/ {
    gpiocustom {
        compatible = "gpio-keys";
        gpiocus0: gpiocus_0 {
            gpios = <&gpio0 22 GPIO_ACTIVE_LOW>;
            label = "Custom gpio 22";
        };
        gpiocus1: gpiocus_1 {
            gpios = <&gpio0 23 GPIO_ACTIVE_LOW>;
            label = "Custom gpio 24";
        };
    };
    aliases {
        gpiocus0 = &gpiocus0;
        gpiocus1 = &gpiocus1;
    };
};

The screenshot of my VS Code workspace:

Hardware setup and wiring diagram :

This is my hardware setup to blink an LED connected to GPIO pin no : 22.

If you notice any error in my wiring circuit , Please notify that.

I have Pristine build the above code without any errors.But , when I flash it in thw nRF52840 DK board, I won't get any output. I connected an LED at GPIO pin 22 with required resistor. I don't know what am I missing?Can you tell me how can I solve this problem?

Ultimately I have to control the 4 Digit Display using these two GPIO pins. If you have idea to do that, Please tell me how can I achieve that.

Thankyou.

-Vicky