GPIO Pins 0.11 0.4 0.5

[Vitaliy Freidovich]

Hi,

I'm trying to do a very simple thing - setting those pins as high or low,

but I see that it simply does not work for those pins, I see no change in led state that I connected to those GPIOs.

I see that with other GPIOs the same code works without any issue.

I thought that those Pins might have been already in use for other purposes, so I tried to remap them in an overlay file, but it still doesn't work.

I guess I'm missing something very simple.

I assume that Pins 0.11, 0.4, and 0.5 can be reassign, and are not special in any way, is this correct?

Am I missing something else? Would appreciate your help understanding :)

I'm using nRF connect SDK 1.7.1, nrf52833 dk, here's my code:

#include <zephyr.h>
#include <zephyr/types.h>
#include <sys/printk.h>
#include <device.h>
#include <devicetree.h>
#include <drivers/gpio.h>
#include <nrfx_gpiote.h>

void init_gpio() {

int result;

gpio_device = device_get_binding(GPIO_DEVICE_NAME);

if (gpio_device == NULL) {

printk("Cannot find GPIO_0 device!\r\n");

return;

}

//configure led pin according to device tree configuration

result = gpio_pin_configure(gpio_device, 11, GPIO_OUTPUT);

if (result < 0) {

printk("Cannot configure reboot pin of GPIO device\n");

return;

}

//configure led pin according to device tree configuration

result = gpio_pin_configure(gpio_device, 4, GPIO_OUTPUT);

if (result < 0) {

printk("Cannot configure reboot pin of GPIO device\n");

return;

}

//configure led pin according to device tree configuration

result = gpio_pin_configure(gpio_device, 5, GPIO_OUTPUT);

if (result < 0) {

printk("Cannot configure reboot pin of GPIO device\n");

return;

}

//configure led pin according to device tree configuration

result = gpio_pin_configure(gpio_device, 8, GPIO_OUTPUT);

if (result < 0) {

printk("Cannot configure reboot pin of GPIO device\n");

return;

}

}

void validation_test_gpio() {

int result11, result5, result4, result8;

while (true) {

printk("setting pins 11, 4, 5, 8 to on\r\n");

gpio_pin_set(gpio_device, 11, 1);

gpio_pin_set(gpio_device, 4, 1);

gpio_pin_set(gpio_device, 5, 1);

gpio_pin_set(gpio_device, 8, 1);

result11 = gpio_pin_get(gpio_device, 11);

result4 = gpio_pin_get(gpio_device, 4);

result5 = gpio_pin_get(gpio_device, 5);

result8 = gpio_pin_get(gpio_device, 8);

printk("value of pin11: %d, pin4: %d, of pin5: %d, of pin8: %d\r\n", result11, result4, result5, result8);

k_sleep(K_SECONDS(5));

printk("setting pins 11, 4, 5, 8 to off\r\n");

gpio_pin_set(gpio_device, 11, 0);

gpio_pin_set(gpio_device, 4, 0);

gpio_pin_set(gpio_device, 5, 0);

gpio_pin_set(gpio_device, 8, 0);

result11 = gpio_pin_get(gpio_device, 11);

result4 = gpio_pin_get(gpio_device, 4);

result5 = gpio_pin_get(gpio_device, 5);

result8 = gpio_pin_get(gpio_device, 8);

printk("value of pin11: %d, pin4: %d, of pin5: %d, of pin8: %d\r\n", result11, result4, result5, result8);

k_sleep(K_SECONDS(5));

}

}

My Current overlay file:

&uart0 {
tx-pin = <29>;
rx-pin = <28>;
//current-speed = <1000000>;
};

/ {
zephyr,user {
/* adjust channel number according to pinmux in board.dts */
io-channels = <&adc 3>;
};
};

Thanks in advance!

Vitaliy

[Vidar Berg]

Hi,

If you look at the silkscreen on the backside of the board you can see that these pins are assigned to the UART and one of the board buttons. You can also read more about the pin assigments in the DK user guide here: Buttons and LEDs and here: Debug input and trace. Are you able to select some of the other pins that are available?

Best regards,

Vidar

[Vitaliy Freidovich]

Hi, 

Thanks for your prompt response.
I'm aware that they are used for a button & UART.
I would like to change that, and reassign them.
How can this be done?

Thanks!
Vitaliy

[Vidar Berg]

Hi Vitaliy,

It worked for me after I disabled the flow control pins in my overlay file. Please try my project and see if you get the same result.

io_test_nrf52833dk.zip

Best regards,

Vidar