1 /*
2 * Copyright (c) 2022 Thomas Stranger
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 #include <zephyr/kernel.h>
8 #include <zephyr/device.h>
9 #include <zephyr/devicetree.h>
10 #include <zephyr/drivers/sensor.h>
11
12 /*
13 * Get a device structure from a devicetree node with compatible
14 * "maxim,ds18b20". (If there are multiple, just pick one.)
15 */
get_ds18b20_device(void)16 static const struct device *get_ds18b20_device(void)
17 {
18 const struct device *const dev = DEVICE_DT_GET_ANY(maxim_ds18b20);
19
20 if (dev == NULL) {
21 /* No such node, or the node does not have status "okay". */
22 printk("\nError: no device found.\n");
23 return NULL;
24 }
25
26 if (!device_is_ready(dev)) {
27 printk("\nError: Device \"%s\" is not ready; "
28 "check the driver initialization logs for errors.\n",
29 dev->name);
30 return NULL;
31 }
32
33 printk("Found device \"%s\", getting sensor data\n", dev->name);
34 return dev;
35 }
36
main(void)37 int main(void)
38 {
39 const struct device *dev = get_ds18b20_device();
40 int res;
41
42 if (dev == NULL) {
43 return 0;
44 }
45
46 while (true) {
47 struct sensor_value temp;
48
49 res = sensor_sample_fetch(dev);
50 if (res != 0) {
51 printk("sample_fetch() failed: %d\n", res);
52 return res;
53 }
54
55 res = sensor_channel_get(dev, SENSOR_CHAN_AMBIENT_TEMP, &temp);
56 if (res != 0) {
57 printk("channel_get() failed: %d\n", res);
58 return res;
59 }
60
61 printk("Temp: %d.%06d\n", temp.val1, temp.val2);
62 k_sleep(K_MSEC(2000));
63 }
64
65 return 0;
66 }
67
