samples: nrf9160: add adc example

Add a simple ADC example.

Signed-off-by: Håkon Alseth <haal@nordicsemi.no>

samples/nrf9160/adc/CMakeLists.txt

@@ -0,0 +1,12 @@
+#
+# Copyright (c) 2018 Nordic Semiconductor
+#
+# SPDX-License-Identifier: LicenseRef-BSD-5-Clause-Nordic
+#
+
+cmake_minimum_required(VERSION 3.8.2)
+
+include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
+project(NONE)
+
+target_sources(app PRIVATE src/main.c)

samples/nrf9160/adc/nrf9160_pca10090.overlay

@@ -0,0 +1,8 @@
+&led0 {
+    gpios = <&gpio0 12 GPIO_INT_ACTIVE_LOW>;
+    status = "enabled";
+};
+
+&adc {
+	status = "ok";
+};

samples/nrf9160/adc/prj.conf

@@ -0,0 +1,21 @@
+CONFIG_BSD_LIBRARY=y
+CONFIG_GPIO=y
+CONFIG_SERIAL=y
+CONFIG_STDOUT_CONSOLE=y
+CONFIG_UART_INTERRUPT_DRIVEN=y
+CONFIG_TEST_RANDOM_GENERATOR=y
+CONFIG_NETWORKING=y
+CONFIG_NET_BUF_USER_DATA_SIZE=1
+CONFIG_NET_SOCKETS_OFFLOAD=y
+CONFIG_NET_SOCKETS=y
+CONFIG_NET_SOCKETS_POSIX_NAMES=y
+CONFIG_NET_RAW_MODE=y
+CONFIG_TRUSTED_EXECUTION_NONSECURE=y
+CONFIG_LOG=n
+CONFIG_LOG_DEFAULT_LEVEL=4
+CONFIG_HEAP_MEM_POOL_SIZE=1024
+# LTE link control
+CONFIG_LTE_LINK_CONTROL=n
+CONFIG_ADC=y
+CONFIG_ADC_0=y
+CONFIG_ADC_NRFX_SAADC=y

samples/nrf9160/adc/src/main.c

@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2018 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-BSD-5-Clause-Nordic
+ */
+
+#include <net/socket.h>
+#include <nrf9160.h>
+#include <stdio.h>
+#include <string.h>
+#include <uart.h>
+#include <adc.h>
+#include <zephyr.h>
+
+struct device *adc_dev;
+
+#if defined(CONFIG_BOARD_NRF52_PCA10040) ||                                    \
+	defined(CONFIG_BOARD_NRF52840_PCA10056) ||                             \
+	defined(CONFIG_BOARD_NRF9160_PCA10090) ||                              \
+	defined(CONFIG_BOARD_NRF52840_BLIP)
+
+#include <hal/nrf_saadc.h>
+#define ADC_DEVICE_NAME DT_ADC_0_NAME
+#define ADC_RESOLUTION 10
+#define ADC_GAIN ADC_GAIN_1_6
+#define ADC_REFERENCE ADC_REF_INTERNAL
+#define ADC_ACQUISITION_TIME ADC_ACQ_TIME(ADC_ACQ_TIME_MICROSECONDS, 10)
+#define ADC_1ST_CHANNEL_ID 0
+#define ADC_1ST_CHANNEL_INPUT NRF_SAADC_INPUT_AIN0
+#define ADC_2ND_CHANNEL_ID 2
+#define ADC_2ND_CHANNEL_INPUT NRF_SAADC_INPUT_AIN2
+
+#endif
+
+static const struct adc_channel_cfg m_1st_channel_cfg = {
+	.gain = ADC_GAIN,
+	.reference = ADC_REFERENCE,
+	.acquisition_time = ADC_ACQUISITION_TIME,
+	.channel_id = ADC_1ST_CHANNEL_ID,
+#if defined(CONFIG_ADC_CONFIGURABLE_INPUTS)
+	.input_positive = ADC_1ST_CHANNEL_INPUT,
+#endif
+};
+
+#define BUFFER_SIZE 1
+static s16_t m_sample_buffer[BUFFER_SIZE];
+
+static int adc_sample(void)
+{
+	int ret;
+
+	const struct adc_sequence sequence = {
+		.channels = BIT(ADC_1ST_CHANNEL_ID),
+		.buffer = m_sample_buffer,
+		.buffer_size = sizeof(m_sample_buffer),
+		.resolution = ADC_RESOLUTION,
+	};
+
+	if (!adc_dev) {
+		return -1;
+	}
+
+	ret = adc_read(adc_dev, &sequence);
+	printk("ADC read err: %d\n", ret);
+
+	/* Print the AIN0 values */
+	for (int i = 0; i < BUFFER_SIZE; i++) {
+		float adc_voltage = 0;
+		adc_voltage = (float)(((float)m_sample_buffer[i] / 1023.0f) *
+				      3600.0f);
+		printk("ADC raw value: %d\n", m_sample_buffer[i]);
+		printf("Measured voltage: %f mV\n", adc_voltage);
+	}
+
+	return ret;
+}
+
+int main(void)
+{
+	int err;
+
+	printk("nrf91 saadc sampling AIN0 (P0.13)\n");
+	printk("Example requires secure_boot to have ");
+	printk("SAADC set to non-secure!\n");
+	printk("If not; BusFault/UsageFault will be triggered\n");
+
+	adc_dev = device_get_binding("ADC_0");
+	if (!adc_dev) {
+		printk("device_get_binding ADC_0 failed\n");
+	}
+	err = adc_channel_setup(adc_dev, &m_1st_channel_cfg);
+	if (err) {
+		printk("Error in adc setup: %d\n", err);
+	}
+
+	/* Trigger offset calibration
+	 * As this generates a _DONE and _RESULT event
+	 * the first result will be incorrect.
+	 */
+	NRF_SAADC_NS->TASKS_CALIBRATEOFFSET = 1;
+	while (1) {
+		err = adc_sample();
+		if (err) {
+			printk("Error in adc sampling: %d\n", err);
+		}
+		k_sleep(500);
+	}
+}

samples/nrf9160/secure_boot/src/main.c

@@ -335,6 +335,9 @@ static void secure_boot_config_peripherals(void)
 	/* Configure TIMER2 as non-secure */
 	secure_boot_config_peripheral(
 		NRFX_PERIPHERAL_ID_GET(NRF_TIMER2_S), 0);
+	/* Configure SAADC as non-secure */
+	secure_boot_config_peripheral(
+		NRFX_PERIPHERAL_ID_GET(NRF_SAADC_S), 0);		
 }
 
 static void secure_boot_config(void)