RE: How to use SAADC example on nrf52832 with Zephyr

Kenneth — Mon, 29 Jun 2020 12:46:01 GMT

P0.11 can't be used for the ADC:
https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/pin.html#qfn48

You need to use a pin that is labeled with AIN*

RE: How to use SAADC example on nrf52832 with Zephyr

Aduka_27 — Mon, 29 Jun 2020 12:01:50 GMT

Thanks a lot. I will take a look and try to find some solution. Also, related to this temperature sensor I found this defined example what do you think about that. I connected the sensor to my device using (VDD, GND and P0.11 pins), but I got some weird results for temperature and humidity. What do you suggest me here, maybe I missed this analog pin (P0.11)?? Thanks in advance!!

/*
 * Copyright (c) 2019 Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr.h>
#include <device.h>
#include <drivers/sensor.h>
#include <stdio.h>

static const char *now_str(void)
{
	static char buf[16]; /* ...HH:MM:SS.MMM */
	u32_t now = k_uptime_get_32();
	unsigned int ms = now % MSEC_PER_SEC;
	unsigned int s;
	unsigned int min;
	unsigned int h;

	now /= MSEC_PER_SEC;
	s = now % 60U;
	now /= 60U;
	min = now % 60U;
	now /= 60U;
	h = now;

	snprintf(buf, sizeof(buf), "%u:%02u:%02u.%03u",
		 h, min, s, ms);
	return buf;
}

void main(void)
{
	const char *const label = DT_LABEL(DT_INST(0, aosong_dht));
	struct device *dht22 = device_get_binding(label);

	if (!dht22) {
		printf("Failed to find sensor %s\n", label);
		return;
	}

	while (true) {
		int rc = sensor_sample_fetch(dht22);

		if (rc != 0) {
			printf("Sensor fetch failed: %d\n", rc);
			break;
		}

		struct sensor_value temperature;
		struct sensor_value humidity;

		rc = sensor_channel_get(dht22, SENSOR_CHAN_AMBIENT_TEMP,
					&temperature);
		if (rc == 0) {
			rc = sensor_channel_get(dht22, SENSOR_CHAN_HUMIDITY,
						&humidity);
		}
		if (rc != 0) {
			printf("get failed: %d\n", rc);
			break;
		}

		printf("[%s]: %.1f Cel ; %.1f %%RH\n",
		       now_str(),
		       sensor_value_to_double(&temperature),
		       sensor_value_to_double(&humidity));
		k_sleep(K_SECONDS(2));
	}
}

RE: How to use SAADC example on nrf52832 with Zephyr

Kenneth — Mon, 29 Jun 2020 11:55:22 GMT

The code you reference won't work. I could find someone have made an ADC example here:
https://medium.com/home-wireless/reading-analog-data-in-zephyr-with-a-nrf52840-e05dae326b9b