nRF52833 DK - configuring GPIO

[BAW]

Hello,

I am new to nRF development. I am going through the nRF Connect SDK Fundamentals course. 

I wanted to configure a GPIO on the nRF52833 DK board as an output and toggle it. In the code below I am trying GPIO P1.01.

I have the following:

#define BLE_NOTIFY_PIN DT_NODELABEL(gpio1) /* Use GPIO1 */
#define BLE_NOTIFY_PIN_NUM 1              /* Use pin P1.01 */
static const struct device *gpio_dev;

int main(void)
{
    int ret;

    gpio_dev = DEVICE_DT_GET(BLE_NOTIFY_PIN);
    if (!device_is_ready(gpio_dev)) {
        printk("Error: GPIO device not ready\n");
        return -1;
    }

    ret = gpio_pin_configure(gpio_dev, BLE_NOTIFY_PIN_NUM, GPIO_OUTPUT);
    printk("gpio_pin_configure returned %d\n", ret);

    while (1) {
         gpio_pin_toggle(gpio_dev, BLE_NOTIFY_PIN_NUM);
         k_sleep(K_MSEC(500));
    }
}

When looking on a scope I see the toggling. I was expecting a square wave but what I am seeing is decaying signals.

I have tried a number of other GPIO pins with the same result.

Any insight on to what I am not understanding would be great.

Thanks,

Brent