Unable to control GPIOs pin in nrf7002DK

[azkpye]

Hello,

For my project I need to control 3 gpios pins. I already found difficult to find gpios that were not already used internally.
I decided to use the gpio0 - 8,9,10 they were used by spi4 but since I don't need it for my project I disabled it 

Here's the overlay : 

&spi4 {
    status = "disabled";
};


&gpio0 {
    status = "okay";
};

&gpio1 {
    status = "okay";
};
/ {

    aliases {
        redpin = &red_pin;
        greenpin = &green_pin;
        bluepin = &blue_pin;
    };

    rgb_leds {
        compatible = "gpio-leds";
        red_pin: red_pin {
            gpios = <&gpio1 3  GPIO_ACTIVE_HIGH>;
            label = "RGB Red Pin";
        };
        green_pin: green_pin {
            gpios = <&gpio0 2 GPIO_ACTIVE_HIGH>;
            label = "RGB Green Pin";
        };
        blue_pin: blue_pin {
            gpios = <&gpio0 3 GPIO_ACTIVE_HIGH>;
            label = "RGB Blue Pin";
        };
    };

};

In my code I init these gpios : 

    if (!gpio_is_ready_dt(&red_led)) {
        LOG_ERR("Red LED GPIO device not ready");
        return -ENODEV;
    }

    if (!gpio_is_ready_dt(&green_led)) {
        LOG_ERR("Green LED GPIO device not ready");
        return -ENODEV;
    }

    if (!gpio_is_ready_dt(&blue_led)) {
        LOG_ERR("Blue LED GPIO device not ready");
        return -ENODEV;
    }

    ret = gpio_pin_configure_dt(&red_led, GPIO_OUTPUT);
    if (ret < 0) {
        LOG_ERR("Failed to configure red LED pin: %d", ret);
        return ret;
    }

    ret = gpio_pin_configure_dt(&green_led, GPIO_OUTPUT);
    if (ret < 0) {
        LOG_ERR("Failed to configure green LED pin: %d", ret);
        return ret;
    }

    ret = gpio_pin_configure_dt(&blue_led, GPIO_OUTPUT);
    if (ret < 0) {
        LOG_ERR("Failed to configure blue LED pin: %d", ret);
        return ret;
    }

And here I set the GPIOS : 

    gpio_pin_set_dt(&red_led, 1);
    gpio_pin_set_dt(&green_led, 1);
    gpio_pin_set_dt(&blue_led, 1);
    k_msleep(1);

    int res = gpio_pin_get_dt(&red_led);
    LOG_INF("Red LED pin state when set to 1: %d", res);

    res = gpio_pin_get_dt(&green_led);
    LOG_INF("Green LED pin state when set to 1: %d", res);

    res = gpio_pin_get_dt(&blue_led);
    LOG_INF("Blue LED pin state when set to 1: %d", res);

And the corresponding logs : 

[00:00:17.750,518] <inf> led: Red LED pin state when set to 1: 0
[00:00:17.750,518] <inf> led: Green LED pin state when set to 1: 0
[00:00:17.750,549] <inf> led: Blue LED pin state when set to 1: 0

I really don't understand what im missing, i tried on different gpios and the result is the same, i cannot control it

Thanks in advance for any help

[Turbo J]

Measure pin voltage with a multimeter. 

The bit that allows pin state to be read back is usually not set when pin mode is "output".

[azkpye]

But I have a led connected to theses pins so I should see the change directly ?
I tried with other gpios that are set 1 to by default (idk how) and I see the led being lighted up but i also cant control them 

[Vidar Berg]

I see now from the original code snippets you posted that you’re trying to read the pin. However, this will only work if you first configure the pin as an input (GPIO_INPUT). You can’t use this API to read the output state.

[azkpye]

And also for my project i would need 10 gpios, it seems complicated no ? 

[Turbo J]

The SBs are on the PCB back side according to the docs.

[azkpye]

So i shorted the bridges, now i'm doing this : 

    int ret = gpio_pin_set_dt(&red_led, 0);
    if (ret < 0) {
        LOG_ERR("Failed to set red LED: %d", ret);
    }


    gpio_pin_toggle_dt(&red_led);
    LOG_ERR("First Red led toggle: %d\n", gpio_pin_get_dt(&red_led));
    k_msleep(1000);
    gpio_pin_toggle_dt(&red_led);
    LOG_ERR("Second Red led toggle: %d\n", gpio_pin_get_dt(&red_led));
    k_msleep(1000);

And i always get 0, I dont understand

[Turbo J]

You still don't put the GPIOs into INPUT mode.

Read the PS/datasheet and check the GPIO code - the pins cannot be read back in output mode unless you do some cursed things in code.

[azkpye]

I want to control a led so it cant be in input mode ?
I thought reading the toggle would make it work, the gpio is connected to the led and doesnt change so i can see that it has no effect

[Vidar Berg]

I don't know which LED you have, but as mentioned earlier, the IO voltage on this board is only 1.8 V. I'm not sure you'll be able to drive your LEDs with this. Do you have a voltmeter, oscilloscope, or logic analyzer you can use to measure the output instead?

EDIT: removed mention about gpio drive strength as it's not relevant here.

[azkpye]

indeed the problem was the voltage...
You say "standard drive strength" is there a way to enhance it ?

[Vidar Berg]

Yes, but the problem is not the drive strength but that the VDD/GPIO voltage that is only 1.8v on this board. You can check the spec. for you LEDs to find out what is needed to turn them on. 

Here's the LED circuit on 7002 DK for comparison:

Ref. https://docs.nordicsemi.com/bundle/ug_nrf7002_dk/page/UG/nrf7002_DK/hw_buttons_leds.html 

[azkpye]

actually i also need theses gpios for a step motor so I really need more voltage from the gpios.
Does gpio open drain would help ? can i use the power of vbat somehow ?