DS18B20¶
About¶
Read and print the temperature measured with one or more DS18B20 sensors.
Source code¶
/**
* @section License
*
* The MIT License (MIT)
*
* Copyright (c) 2014-2016, Erik Moqvist
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
* This file is part of the Simba project.
*/
#include "simba.h"
int main()
{
struct owi_driver_t owi;
struct ds18b20_driver_t ds;
struct owi_device_t devices[4];
char temperature[16], *temperature_p;
int number_of_sensors;
int i;
/* Initialization. */
sys_start();
ds18b20_module_init();
owi_init(&owi, &pin_d7_dev, devices, membersof(devices));
ds18b20_init(&ds, &owi);
time_busy_wait_us(50000);
/* Search for devices on the OWI bus. */
number_of_sensors = owi_search(&owi);
std_printf(FSTR("Number of sensors: %d\r\n"), number_of_sensors);
while (1) {
/* Take a new temperature sample. */
ds18b20_convert(&ds);
for (i = 0; i < owi.len; i++) {
if (devices[i].id[0] != DS18B20_FAMILY_CODE) {
continue;
}
temperature_p = ds18b20_get_temperature_str(&ds,
devices[i].id,
temperature);
std_printf(FSTR("Device id: %02x %02x %02x %02x %02x %02x %02x %02x,"
" Temperature: %s\r\n"),
(unsigned int)devices[i].id[0],
(unsigned int)devices[i].id[1],
(unsigned int)devices[i].id[2],
(unsigned int)devices[i].id[3],
(unsigned int)devices[i].id[4],
(unsigned int)devices[i].id[5],
(unsigned int)devices[i].id[6],
(unsigned int)devices[i].id[7],
temperature_p);
}
}
return (0);
}
The source code can also be found on Github in the examples/ds18b20 folder.
Build and run¶
Build and run the application.
$ cd examples/ds18b20
$ make -s BOARD=<board> run
Number of sensors: 2
Device id: 28 9c 1d 5d 05 00 00 32, Temperature: 22.6250
Device id: 28 95 32 5d 05 00 00 33, Temperature: 22.6875