nrf52840 dongle PCA10059 GPIO Out LED

[shaneelliott]

I am trying to get an LED attached to GPIO to turn on. I have tried all documented methods I could find but with no success. I have no issue controlling the onboard LEDS but I cannot seem to configure a GPIO as an output. I also have no issue configuring a GPIO as an input. The LED 100% works as it lights if attached to VDD pin or when connected to a GPIO pin set as an input. My wiring for the LED is between the GND and GPIO pin (0.2) and i have tried using both set and clear but with no result. Any ideas would be greatly appreciated.

[Einar Thorsrud]

Hi,

Which method did you try, and which pin have you conneced the LED to? Also, which SDK are you using?

The simplest way to control a GPIO (which control the LED) is to just set it directly using nrf_gpio_pin_set() and nrf_gpio_pin_clear() with the pin number as parameter. For that you need "#include <hal/nrf_gpio.h>", and you need to first configure the pin as output using nrf_gpio_cfg_output(), with the pin number as parameter here as well.

[shaneelliott]

yes that was the exact code i tried.

#define LED_PIN NRF_GPIO_PIN_MAP(0,2)

void led_setup(void)
{
ret_code_t err_code;

// Configure the output pin
nrf_gpio_cfg_output(LED_PIN);
}

void led_on(void) {
nrf_gpio_pin_clear(LED_PIN);
}

void led_off(void) {
nrf_gpio_pin_set(LED_PIN);
}

I am using SDK17.1.0. I have tried on other PINs as well. Also I am using a soft device in my main code but have tried with and without a soft device present

[Einar Thorsrud]

Hi,

I see. This looks correct. Could it be that you are missing an include or similar - do you get warnings when building? Or can you share the full code?

Also, if you have connected the LED to VDD for some time without a series resistor (if I read you correctly) you may have damaged it, so it is worth checking if it still works. Perhaps just measure the voltage on P0.02 to verify if you get it set and cleared correctly?

[shaneelliott]

yes i have double checked the voltage output on the pin and get nothing. The led still looks good. Her is the full source code. LED is connected (0.9) in this https://drive.google.com/file/d/18iL3t57LD_V3lU2_xP-JLgGanAloNKDK/view?usp=sharing

[Einar Thorsrud]

I don't see any obvious issues here. Can you call your led_on() and led_off() function after led_setup() in your main function and verify with a debugger that they actually run? If so, it should work. You can also step down into them when debugging to verify that it does and that the OUT register is set as it should (note that you should do this before initializing the SoftDevice, as that complicates debugging a bit).

[shaneelliott]

I unfortunately don't have a debugger attached to nrf52840 dongle which problem solving pretty tricky

[shaneelliott]

I will try running the following 

led_setup();
led_on();
nrf_delay_ms(1000); // Sleep/block for 1 second
led_off();
nrf_delay_ms(1000); // Sleep/block for 1 second
led_on();

but also just tried changing the pin map of the board LED in pca10059.h so basically its gets setup exactly the same as the onboard LED's but this did not help 

[shaneelliott]

Not a pretty solution but this works.

void pinOn(uint32_t pin) {
    // Set pin direction as input using DIRCLR register
    NRF_GPIO->DIRCLR = (1 << pin);

    NRF_GPIO->PIN_CNF[pin] = (NRF_GPIO_PIN_DIR_INPUT << GPIO_PIN_CNF_DIR_Pos)
                               | (NRF_GPIO_PIN_INPUT_CONNECT << GPIO_PIN_CNF_INPUT_Pos)
                               | (NRF_GPIO_PIN_PULLUP << GPIO_PIN_CNF_PULL_Pos)
                               | (NRF_GPIO_PIN_S0S1 << GPIO_PIN_CNF_DRIVE_Pos)
                               | (NRF_GPIO_PIN_NOSENSE << GPIO_PIN_CNF_SENSE_Pos);
}

void clearPin(uint32_t pin) {
    // Reset PIN_CNF register to default value
    NRF_GPIO->PIN_CNF[pin] = 0;  // All bits set to 0 (default state)
    
    // Clear direction (set as input - default state)
    NRF_GPIO->DIRCLR = (1 << pin);
    
    // Clear output value
    NRF_GPIO->OUTCLR = (1 << pin);
}