Read adc for nrf51822

[beckmx]

Hello guys, I have been wanting to read one ADC pin, P0.04 but I am able to read it, it keeps giving me an error when trying to read, i have changed the channel_id but still no luck, if someone has experience i will appreciate it a lot :)

#include <zephyr/types.h>
#include <bluetooth/bluetooth.h>
#include <pm/pm.h>
#include <drivers/adc.h>
#include <drivers/gpio.h>
#include <sys/printk.h>

/* MISSING ADVERTISEMENT_PAYLOAD on purpose */
static const struct bt_data advertisement_payload[] = {
  BT_DATA_BYTES(BT_DATA_MANUFACTURER_DATA,0,0,0,0,0,0,0,0)
};

bt_addr_t addr = { 0,0,0,0,0,0 };
static void bt_ready(int err)
{
	/* Bluetooth initialization error handler */
	if (err) { return; }

	/* Start advertising */
	err = bt_le_adv_start(
		BT_LE_ADV_NCONN_IDENTITY, advertisement_payload, 
		ARRAY_SIZE(advertisement_payload),
		NULL, // Don't send the second packet with device name
		0
	);
	if (err) { return; }
}

int read_adc_value(void)
{
    const struct device *adc_dev = device_get_binding(DT_LABEL(DT_NODELABEL(adc)));
    int ret;
    int16_t sample_buffer[1];
    
    // Assuming that P0.04 is mapped to channel 0?
    const uint8_t channel_id = 0;  
    
    struct adc_channel_cfg channel_cfg = {
        .gain             = ADC_GAIN_1,
        .reference        = ADC_REF_INTERNAL,
        .acquisition_time = ADC_ACQ_TIME_DEFAULT,
        .channel_id       = channel_id,
        .differential     = 0,
    };

    struct adc_sequence sequence = {
        .channels    = BIT(channel_id),
        .buffer      = sample_buffer,
        .buffer_size = sizeof(sample_buffer),
        .resolution  = 12,
    };

    if (!adc_dev) {
        printk("ADC device not found\n");
        return -1;
    }

    ret = adc_channel_setup(adc_dev, &channel_cfg);
    if (ret != 0) {
        printk("Setting up of the ADC channel failed with code %d\n", ret);
        return -1;
    }

    ret = adc_read(adc_dev, &sequence);
    if (ret != 0) {
        printk("ADC reading failed with code %d\n", ret);
        return -1;
    }

    return sample_buffer[0];
}
void main(void)
{
	printk("hello there\n");
	bt_addr_le_t ble_addr_0 = { BT_ADDR_LE_RANDOM, addr };
	bt_id_create(&ble_addr_0, NULL);
	bt_enable(bt_ready);

	// After starting advertising, put the system to sleep for 60 seconds
	while (1) {
		k_sleep(K_SECONDS(3));
		bt_le_adv_stop();
		int adc_value = read_adc_value();
		printk("ADC value:");
		printk(adc_value);
		printk("\n");

		bt_addr_le_t ble_addr_1 = { BT_ADDR_LE_RANDOM, addr };
		bt_id_create(&ble_addr_1, NULL);
		k_sleep(K_SECONDS(5));
		bt_le_adv_start(
			BT_LE_ADV_NCONN_IDENTITY, advertisement_payload, 
			ARRAY_SIZE(advertisement_payload),
			NULL, // Don't send the second packet with device name
			0
		);
	}
	
}