Inquiries regarding adc.

[ozoz05]

Hello.
"zephyr/samples/drivers/adc/adc_dt" example sample added an additional adcpin.

When reading the sensor value connected to AIN0, the value of AIN1 is also changing.

How can I solve this?

#include <zephyr/logging/log.h>
LOG_MODULE_DECLARE( sta, CONFIG_LOG_DEFAULT_LEVEL );

#include <zephyr/kernel.h>
#include <errno.h>
#include <stdio.h>

#include <zephyr/device.h>
#include <zephyr/devicetree.h>
#include <zephyr/drivers/adc.h>
#include <zephyr/drivers/gpio.h>

#include "ADC.h"
#include "deviceInformation.h"


//! Variable to identify the TCP Client thread
static struct k_thread ADCThread;
//! Stack size for the TCP_CLIENT thread
#define ADC_STACK_SIZE 2*1024
//! ADC thread priority level
#define ADC_PRIORITY 7

//! ADC stack definition
K_THREAD_STACK_DEFINE(ADC_STACK, ADC_STACK_SIZE);
//! Variable to identify the ADC thread
static struct k_thread ADCThread;

#define LEDS_NODE DT_PATH(leds)
#define GPIO_SPEC_AND_COMMA(button_or_led) GPIO_DT_SPEC_GET(button_or_led, gpios),


#if !DT_NODE_EXISTS(DT_PATH(zephyr_user)) || \
	!DT_NODE_HAS_PROP(DT_PATH(zephyr_user), io_channels)
#error "No suitable devicetree overlay specified"
#endif


#define DT_SPEC_AND_COMMA(node_id, prop, idx) \
	ADC_DT_SPEC_GET_BY_IDX(node_id, idx),


/* Data of ADC io-channels specified in devicetree. */
static const struct adc_dt_spec adc_channels[] = {
	DT_FOREACH_PROP_ELEM(DT_PATH(zephyr_user), io_channels,
			     DT_SPEC_AND_COMMA)
};

uint16_t cnt = 0;

// static const struct gpio_dt_spec sensor_en = GPIO_DT_SPEC_GET(DT_PATH(zephyr_user), sensor_en_gpios);
static const struct gpio_dt_spec My_gpios[] = {
	GPIO_DT_SPEC_GET(DT_PATH(zephyr_user), bat_en_gpios),
	GPIO_DT_SPEC_GET(DT_PATH(zephyr_user), dt1_gpios),
	GPIO_DT_SPEC_GET(DT_PATH(zephyr_user), dt2_gpios)
};

static const struct gpio_dt_spec leds[] = {
#if DT_NODE_EXISTS(LEDS_NODE)
	DT_FOREACH_CHILD(LEDS_NODE, GPIO_SPEC_AND_COMMA)
#endif
};

void ADC( void )
{
	int err;
	uint32_t count = 0;
	uint16_t buf;
	struct adc_sequence sequence = {
		.buffer = &buf,
		/* buffer size in bytes, not number of samples */
		.buffer_size = sizeof(buf),
	};

	/* Configure channels individually prior to sampling. */
	for (size_t i = 0U; i < ARRAY_SIZE(adc_channels); i++) {
		if (!adc_is_ready_dt(&adc_channels[i])) {
			LOG_INF("ADC controller device %s not ready\n", adc_channels[i].dev->name);
			return 0;
		}

		err = adc_channel_setup_dt(&adc_channels[i]);
		if (err < 0) {
			LOG_INF("Could not setup channel #%d (%d)\n", i, err);
			return 0;
		}
	}

	int ret;

	LOG_INF( "ADC Test");

	for (size_t i = 0; i < ARRAY_SIZE(leds); i++) {
		err = gpio_pin_configure_dt(&leds[i], GPIO_OUTPUT);
		if (err) {
			LOG_ERR("Cannot configure LED gpio");
			return err;
		}
	}

	if (!gpio_is_ready_dt(&My_gpios)) {
		return 0;
	}

	gpio_pin_configure_dt(&My_gpios[0], GPIO_OUTPUT);
	gpio_pin_configure_dt(&My_gpios[1], GPIO_OUTPUT);
	gpio_pin_configure_dt(&My_gpios[2], GPIO_OUTPUT);


	gpio_pin_set_dt(&My_gpios[0], 1);		//BAT_EN
	gpio_pin_set_dt(&My_gpios[1], 0);
	gpio_pin_set_dt(&My_gpios[2], 1);

	while(1) {
		// LOG_INF( "CNT : %d", cnt);
		// cnt++;
		printk("ADC reading[%u]:\n", count++);

		for (size_t i = 0U; i < ARRAY_SIZE(adc_channels); i++) {
			int32_t val_mv;

			printk("- %s, channel %d: ",
			       adc_channels[i].dev->name,
			       adc_channels[i].channel_id);

			(void)adc_sequence_init_dt(&adc_channels[i], &sequence);

			err = adc_read_dt(&adc_channels[i], &sequence);
			if (err < 0) {
				printk("Could not read (%d)\n", err);
				continue;
			}

			/*
			 * If using differential mode, the 16 bit value
			 * in the ADC sample buffer should be a signed 2's
			 * complement value.
			 */
			if (adc_channels[i].channel_cfg.differential) {
				val_mv = (int32_t)((int16_t)buf);
			} else {
				val_mv = (int32_t)buf;
			}
			if(val_mv < (int32_t)0 || val_mv > (int32_t)16384) val_mv = (int32_t)0;
			printk("%"PRId32, val_mv);
			err = adc_raw_to_millivolts_dt(&adc_channels[i],
						       &val_mv);
			/* conversion to mV may not be supported, skip if not */
			if (err < 0) {
				printk(" (value in mV not available)\n");
			} else {
				printk(" = %"PRId32" mV\n", val_mv);
			}
		}
		k_msleep(500);
	}
}


/*! Task_ADC_Init initializes the task ADC
*
* @brief ADC initialization
*/
void Task_ADC_Init( void ){
	
	k_thread_create	(														
					&ADCThread,										
					ADC_STACK,										
					ADC_STACK_SIZE,									
					(k_thread_entry_t)ADC,							
					NULL,													
					NULL,													
					NULL,													
					ADC_PRIORITY,									
					0,														
					K_NO_WAIT);	

	 k_thread_name_set(&ADCThread, "ADC");
	 k_thread_start(&ADCThread);
};