diff --git a/lib/sensor_ds18b20.c b/lib/sensor_ds18b20.c
new file mode 100644
index 0000000..1923837
--- /dev/null
+++ b/lib/sensor_ds18b20.c
@@ -0,0 +1,196 @@
+/* This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ *
+ */
+/** library for Maxim DS18B20 digital temperature sensor (using 1-Wire protocol) (code)
+ * @file sensor_ds18b20.c
+ * @author King Kévin
+ * @date 2017
+ * @note peripherals used: 1-Wire (timer @ref onewire_master_timer, GPIO @ref onewire_master_gpio)
+ * @warning this library does not support parasite power mode and alarms
+ */
+/* standard libraries */
+#include // standard integer types
+#include // boolean type
+#include // size_t definition
+#include // NAN definition
+
+/* own libraries */
+#include "global.h" // help macros
+#include "onewire_master.h" // 1-Wire utilities
+#include "sensor_ds18b20.h" // own definitions
+
+/** remember number of DS18B20 sensors on 1-Wire bus for certain functions */
+uint64_t sensors = 0;
+/** remember if only DS18B20 sensors on 1-Wire bus for certain functions */
+bool only = false;
+/** remember code of last sensor **/
+uint64_t last = 0;
+
+void sensor_ds18b20_setup(void)
+{
+ onewire_master_setup(); // setup 1-Wire peripheral to communicate with sensors on bus
+ sensor_ds18b20_number(); // scan for sensor (remembers sensor number and exclusivity)
+}
+
+uint64_t sensor_ds18b20_number(void)
+{
+ sensors = 0; // reset number
+ only = true; // reset state
+ uint64_t code = 0; // ROM code found (use 0 to start from scratch)
+ bool more = true; // save if other additional slaves exist
+
+ while (more) { // scan for all 1-Wire slaves
+ if (!onewire_master_reset()) { // send reset to start communication
+ return 0; // no slave presence detected
+ }
+ more = onewire_master_rom_search(&code, false); // get next slave ROM code (without alarm)
+ if (0==code) { // error occurred
+ return 0;
+ }
+ if (0x28==(code&0xff)) { // family code (8-LSb) for DS18B20 sensors is 0x28
+ last = code; // save last found code
+ sensors++; // we found an additional sensor
+ } else {
+ only = false; // we found a slave which is not a sensor
+ }
+ }
+
+ return sensors;
+}
+
+bool sensor_ds18b20_only(void)
+{
+ sensor_ds18b20_number(); // this also checks for exclusivity
+ return only;
+}
+
+bool sensor_ds18b20_list(uint64_t* code)
+{
+ if (!onewire_master_reset()) { // send reset to start communication
+ return false; // no slave presence detected
+ }
+ onewire_master_rom_search(code, false); // get next code
+ return (last!=*code); // verify if the last has been found
+}
+
+bool sensor_ds18b20_convert(uint64_t code)
+{
+ if (0==code && !only) { // asked for broadcast but there are different slaves on bus
+ return false; // broadcast not possible when there are also different slaves on bus
+ }
+
+ // send reset pulse
+ if (!onewire_master_reset()) { // send reset to start communication
+ return false; // no slave presence detected
+ }
+
+ // send ROM command to select slave(s)
+ if (0==code) { // broadcast convert
+ if (!onewire_master_rom_skip()) { // select all slaves
+ return false; // ROM command failed
+ }
+ } else {
+ if (!onewire_master_rom_match(code)) { // select specific slave
+ return false; // ROM command failed
+ }
+ }
+
+ // send convert T function command
+ return onewire_master_function_read(0x44, NULL, 0);
+}
+
+float sensor_ds18b20_temperature(uint64_t code)
+{
+ if (0==code && (sensors>1 || !only)) { // broadcast read requested
+ return NAN; // this function is not possible when several sensors or other devices are present
+ }
+
+ // send reset pulse
+ if (!onewire_master_reset()) { // send reset to start communication
+ return NAN; // no slave presence detected
+ }
+
+ // send ROM command to select slave
+ if (!onewire_master_rom_match(code)) { // select specific slave
+ return NAN; // ROM command failed
+ }
+
+ // read scratchpad to get temperature (on byte 0 and 1)
+ uint8_t scratchpad[9] = {0}; // to store read scratchpad
+ if (!onewire_master_function_read(0xbe, scratchpad, sizeof(scratchpad)*8)) { // read complete scratchpad
+ return NAN; // error occurred during read
+ }
+
+ // verify if data is valid
+ if (onewire_master_crc(scratchpad, sizeof(scratchpad))) { // check CRC checksum
+ return NAN; // data corrupted
+ }
+
+ // calculate temperature (stored as int16_t but on 0.125 C steps)
+ return ((int16_t)(scratchpad[1]<<8)+scratchpad[0])/16.0; // get temperature (on < 16 precision the last bits are undefined, but that doesn't matter for the end result since the lower precision is still provided)
+}
+
+bool sensor_ds18b20_precision(uint64_t code, uint8_t precision)
+{
+ if (precision<9 || precision>12) { // check input
+ return false; // wrong precision value
+ }
+
+ if (0==code && !only) { // asked for broadcast but there are different slaves on bus
+ return false; // broadcast not possible when there are also different slaves on bus
+ }
+
+ // send reset pulse
+ if (!onewire_master_reset()) { // send reset to start communication
+ return false; // no slave presence detected
+ }
+
+ // send ROM command to select slave(s)
+ if (0==code) { // broadcast convert
+ if (!onewire_master_rom_skip()) { // select all slaves
+ return false; // ROM command failed
+ }
+ } else {
+ if (!onewire_master_rom_match(code)) { // select specific slave
+ return false; // ROM command failed
+ }
+ }
+
+ // read scratchpad to get alarm values (on byte 2 and 3)
+ uint8_t scratchpad[9] = {0}; // to store read scratchpad
+ if (!onewire_master_function_read(0xbe, scratchpad, sizeof(scratchpad)*8)) { // read complete scratchpad
+ return false; // error occurred during read
+ }
+
+ // verify if data is valid
+ if (onewire_master_crc(scratchpad, sizeof(scratchpad))) { // check CRC checksum
+ return false; // data corrupted
+ }
+
+ // send new configuration (and keep the alarm values)
+ uint8_t configuration[3] = {0}; // to store T_HIGH, T_LOW, and configuration
+ configuration[0] = scratchpad[2]; // keep T_HIGH
+ configuration[1] = scratchpad[3]; // keep T_LOW
+ configuration[2] = 0x1f+((precision-9)<<5); // set precision bit (R1-R0 on bit 6-5)
+ if (!onewire_master_function_write(0x4e, configuration, sizeof(configuration)*8)) { // write scratchpad with new configuration (all three bytes must be written)
+ return false; // error occurred during write
+ }
+
+ // store new configuration into sensor's EEPROM for retrieval on next power up
+ if (!onewire_master_function_read(0x48, NULL, 0)) { // copy scratchpad (to EEPROM)
+ return false; // error during copy
+ }
+
+ return true;
+}
diff --git a/lib/sensor_ds18b20.h b/lib/sensor_ds18b20.h
new file mode 100644
index 0000000..f813dc0
--- /dev/null
+++ b/lib/sensor_ds18b20.h
@@ -0,0 +1,56 @@
+/* This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ *
+ */
+/** library for Maxim DS18B20 digital temperature sensor (using 1-Wire protocol) (API)
+ * @file sensor_ds18b20.h
+ * @author King Kévin
+ * @date 2017
+ * @note peripherals used: 1-Wire (timer @ref onewire_master_timer, GPIO @ref onewire_master_gpio)
+ * @warning this library does not support parasite power mode and alarms
+ */
+#pragma once
+
+/** setup 1-Wire peripheral to communicate with sensors on bus */
+void sensor_ds18b20_setup(void);
+/** get number of DS18B20 sensors on bus
+ * @return number of DS18B20 sensors on bus
+ */
+uint64_t sensor_ds18b20_number(void);
+/** verify if only DS18B20 sensors are on the bus
+ * @return if only DS18B20 sensors are on the bus
+ */
+bool sensor_ds18b20_only(void);
+/** send all DS18B20 slaves on the bus
+ * @param[out] code ROM code for sensor (0 if error occurred)
+ * @return if an additional sensors have been detected
+ */
+bool sensor_ds18b20_list(uint64_t* code);
+/** start converting (e.g. measuring) temperature
+ * @waning conversion time to wait before reading temperature depends on the resolution set (9 bits: 93.75ms, 10 bits: 187.5ms, 11 bits: 375ms, 12 bits: 950ms)
+ * @param[in] code ROM code of sensor to start conversion on (0 for all, if only DS18B20 sensors are on the bus)
+ * @return if conversion started
+ */
+bool sensor_ds18b20_convert(uint64_t code);
+/** get converted temperature
+ * @note 85.0 C is the default temperature when no conversion has been performed
+ * @param[in] code ROM code of sensor
+ * @return temperature (NaN if error)
+ */
+float sensor_ds18b20_temperature(uint64_t code);
+/** set conversion precision
+ * @param[in] code ROM code of sensor to start conversion on (0 for all, if only DS18B20 sensors are on the bus)
+ * @param[in] precision precision in bits (9-12)
+ * @return if operation succeeded
+ */
+bool sensor_ds18b20_precision(uint64_t code, uint8_t precision);