GPIO9 & 10 won't operate independently using zephyr (but OK with rRF5 SDK)

RE: GPIO9 & 10 won't operate independently using zephyr (but OK with rRF5 SDK)

Håkon Alseth — Thu, 24 Apr 2025 08:25:19 GMT

Hi,

Glad to hear that you got it working!

I can confirm your suspicion related to the leakage between the pins, there will be a small leakage when they are driven differentially, as shown by "INFC_LEAK" in the GPIO el.specs:

https://docs.nordicsemi.com/bundle/ps_nrf52832/page/gpio.html#d918e75197

Kind regards,

Håkon

RE: GPIO9 & 10 won't operate independently using zephyr (but OK with rRF5 SDK)

Nick_RA — Wed, 23 Apr 2025 18:33:06 GMT

Actually I now have it working!

When experimenting and trying code I have only been using one of the pins at any time. So for example I toggle P0.09. In this case P0.10 is in its default state which I assume is an input, and there must be enough leakage between the pins - either from the internal protection circuitry or maybe even solder flux residue - to make the FET Q2 turn on.

If I set both to outputs, then toggle either pin, all is good.

RE: GPIO9 & 10 won't operate independently using zephyr (but OK with rRF5 SDK)

Nick_RA — Wed, 23 Apr 2025 07:45:48 GMT

This is a custom board. The pins simply drive a couple of FETs, and in my application they will be pulsed for 1 sec. At the moment in my development rig the FETs are just driving a couple of LEDs.

Actually before now I hadn't noticed the gpio/nfc caveat. Using SDK 17.1 I just set the pins to output using nrf_gpio_cfg_output(pin) and it just worked. I guess that's because NFC is disabled in sdconfig.h?

Here's a snip of the schematic

RE: GPIO9 & 10 won't operate independently using zephyr (but OK with rRF5 SDK)

Håkon Alseth — Wed, 23 Apr 2025 07:13:04 GMT

Hi,

I might have misread your initial post. When you state that this works in nRF5 SDK, do you mean the GPIOs themselves, ie. P0.09/P0.10?

Have you modified the nRF52-DK as described here to re-route the NFC interface?

https://docs.nordicsemi.com/bundle/ug_nrf52832_dk/page/UG/dk/hw_nfc_if.html#d37e110

Kind regards,

Håkon

RE: GPIO9 & 10 won't operate independently using zephyr (but OK with rRF5 SDK)

Nick_RA — Tue, 22 Apr 2025 17:01:39 GMT

No that doesn't seem to have fixed it 😞

Maybe there is something wrong with my dts file?

Here is the code I am using to test now using dts this time; all I am doing is changing line#9 with led0 led1 led2 led3

#include <stdio.h>
#include <zephyr/kernel.h>
#include <zephyr/drivers/gpio.h>
#include <hal/nrf_gpio.h>

#define GPIO_NODE  DT_NODELABEL(gpio0)
#define GPIO_NAME	DEVICE_DT_NAME(GPIO_NODE)
#define RUN_LED_BLINK_INTERVAL 300
#define OD2_NODE DT_NODELABEL(led2)

int main(void)
{
	static const struct gpio_dt_spec od2_spec = GPIO_DT_SPEC_GET(OD2_NODE, gpios);
	gpio_pin_configure_dt(&od2_spec, GPIO_OUTPUT); 
    printk("Hello\n");
	for (;;) {
		gpio_pin_set_dt(&od2_spec, 1);
		k_sleep(K_MSEC(RUN_LED_BLINK_INTERVAL));
		gpio_pin_set_dt(&od2_spec, 0);
		k_sleep(K_MSEC(RUN_LED_BLINK_INTERVAL));
	}
		return 0;
}

/dts-v1/;
#include <nordic/nrf52832_qfaa.dtsi>
#include "lptb-pinctrl.dtsi"
#include <zephyr/dt-bindings/input/input-event-codes.h>


/ {
	model = "Custom Board auto generated by nRF Connect for VS Code";
	compatible = "react,lptb";

	chosen {
		zephyr,sram = &sram0;
		zephyr,flash = &flash0;
		zephyr,code-partition = &slot0_partition;
		zephyr,console =  &uart0 ;
		zephyr,shell-uart =  &uart0 ;
		zephyr,uart-mcumgr = &uart0;
	};
	leds {
		compatible = "gpio-leds";
		led0: led_0 {
			gpios = <&gpio0 7 GPIO_ACTIVE_HIGH>;
			label = "Green LED 0";
		};
		led1: led_1 {
			gpios = <&gpio0 8 GPIO_ACTIVE_HIGH>;
			label = "Green LED 1";
		};
		led2: led_2 {
			gpios = <&gpio0 9 GPIO_ACTIVE_HIGH>;
			label = "Green LED 2";
		};
		led3: led_3 {
			gpios = <&gpio0 10 GPIO_ACTIVE_HIGH>;
			label = "Green LED 3";
		};
	};
	
 
	buttons {
		compatible = "gpio-keys";
		button0: button_0 {
			gpios = <&gpio0 17 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
			label = "Push button switch 0";
			zephyr,code = <INPUT_KEY_0>;
		};
		button1: button_1 {
			gpios = <&gpio0 18 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
			label = "Push button switch 1";
			zephyr,code = <INPUT_KEY_1>;
		};
		button2: button_2 {
			gpios = <&gpio0 19 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
			label = "Push button switch 2";
			zephyr,code = <INPUT_KEY_2>;
		};
		button3: button_3 {
			gpios = <&gpio0 20 (GPIO_PULL_UP | GPIO_ACTIVE_LOW)>;
			label = "Push button switch 3";
			zephyr,code = <INPUT_KEY_3>;
		};
	};



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

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

		boot_partition: partition@0 {
			label = "mcuboot";
			reg = <0x00000000 DT_SIZE_K(48)>;
		};

		slot0_partition: partition@c000 {
			label = "image-0";
			reg = <0x0000c000 DT_SIZE_K(220)>;
		};

		slot1_partition: partition@43000 {
			label = "image-1";
			reg = <0x00043000 DT_SIZE_K(220)>;
		};

		storage_partition: partition@7a000 {
			label = "storage";
			reg = <0x0007a000 DT_SIZE_K(24)>;
		};
	};
};

&gpiote {
	status = "okay";
};

&gpio0 {
	status = "okay";
};

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

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

&uicr {
	status = "okay";
	nfct-pins-as-gpios;
};

Edit: Sorry, forgot to say this is using NCS 2.9.0

RE: GPIO9 & 10 won't operate independently using zephyr (but OK with rRF5 SDK)

Håkon Alseth — Tue, 22 Apr 2025 14:01:45 GMT

Hi,

Are you using a newer version of NCS?

If yes, then the NFC pin configuration is moved to device tree. Try adding this to your overlay and see if the GPIOs now works as expected:

&uicr {
	nfct-pins-as-gpios;
};

Kind regards,

Håkon