![\"\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2018\/07\/multiple-ds18b20-temp-sensor-thumbnail.jpg?resize=750%2C421&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\nIf you would like to build a web server displaying readings from multiple sensors, follow the next tutorial: ESP32 Plot Sensor Readings in Charts (Multiple DS18B20 Sensors)<\/a><\/p>\n\n\n\n You might also like reading other DS18B20 guides:<\/p>\n\n\n\n The DS18B20 temperature sensor is a 1-wire digital temperature sensor. Each sensor has a unique 64-bit serial number, which means you can use many sensors on the same data bus (this means many sensors connected to the same GPIO). This is specially useful for data logging and temperature control projects. The DS18B20 is a great sensor because it is cheap, accurate and very easy to use.<\/p>\n\n\n\n The following figure shows the DS18B20 temperature.<\/p>\n\n\n\n Note: there’s also a waterproof version of the DS18B20 temperature sensor<\/a>.<\/p>\n\n\n\n Here’s the main specifications of the DS18B20 temperature sensor:<\/p>\n\n\n\n From left to right: the first pin is GND<\/span>, the second is data, and the rightmost pin is VCC<\/span>.<\/p>\n\n\n\n Check the links below to compare the DS18B20 temperature sensor price on different stores:<\/p>\n\n\n\n Here’s a list of the parts you need to follow this example:<\/p>\n\n\n\n You can use the preceding links or go directly to MakerAdvisor.com\/tools<\/a> to find all the parts for your projects at the best price!<\/p> When wiring the DS18B20 temperature sensor you need to add a 4.7k Ohm resistor between VCC and the data line. The following schematic shows an example for three sensors (you can add more sensors if needed).<\/p>\n\n\n\n In the previous schematic, the round side of the sensor is facing backwards. The flat part is facing forward.<\/p>\n\n\n\n There\u2019s an add-on for the Arduino IDE that allows you to program the ESP32 using the Arduino IDE and its programming language. Follow one of the next tutorials to prepare your Arduino IDE to work with the ESP32, if you haven\u2019t already.<\/p>\n\n\n\n Before uploading the code, you need to install two libraries in your Arduino IDE. The OneWire library by Paul Stoffregen<\/a> and the Dallas Temperature library<\/a>. Follow the next steps to install those libraries.<\/p>\n\n\n\n Each DS18B20 temperature sensor has a serial number assigned to it. First, you need to find that number to label each sensor accordingly. You need to do this, so that later you know from which sensor you’re reading the temperature from.<\/p>\n\n\n\n Upload the following code to the ESP32. Make sure you have the right board and COM port selected.<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n Wire just one sensor at a time to find its address (or successively add a new sensor) so that you’re able to identify each one by its address. Then, you can add a physical label to each sensor. Open the Serial Monitor at a baud rate of 9600 and you should get something as follows (but with different addresses):<\/p>\n\n\n\n Untick the “Autoscroll<\/strong>” option so that you’re able to copy the addresses. In our case we’ve got the following addresses:<\/p>\n\n\n\n Getting the temperature from multiple sensors on the same common data bus is very straightforward.<\/p>\n\n\n\n The example code below reads temperature in Celsius and Fahrenheit from each sensor and prints the results in the Serial Monitor.<\/p>\n\n\n View raw code<\/a><\/p>\n\n\n\n Open the Serial Monitor at a baud rate of 115200 and you should get something similar.<\/p>\n\n\n\n First, include the needed libraries:<\/p>\n\n\n\n Create the instances needed for the temperature sensor. The temperature sensor is connected to GPIO 15<\/span>.<\/p>\n\n\n\n Start the Dallas temperature library for the DS18B20 sensor.<\/p>\n\n\n\n Then, enter the addresses you’ve found previously for each temperature sensor. In our case, we have the following:<\/p>\n\n\n\n In the setup()<\/span>, initialize a Serial communication and start the Dallas temperature library for the DS18B20 sensor.<\/p>\n\n\n\n In the loop()<\/span>, request the temperatures both in Celsius and Fahrenheit and print the results on the Serial Monitor.<\/p>\n\n\n\n First, you need to request the temperatures using the following line of code:<\/p>\n\n\n\n Then, you can request the temperature by using the sensors address:<\/p>\n\n\n\n For example, to request temperature in Celsius for sensor 1, you use:<\/p>\n\n\n\n In which sensor1<\/span> is a variable that holds the address of the first sensor.<\/p>\n\n\n\n This is just a simple sketch example to show you how to get temperature from multiple DS18B20 sensors using the ESP32. This code is also compatible with the ESP8266 and Arduino boards.<\/p>\n\n\n\n Getting temperature from multiple DS18B20 temperature sensors is specially useful in monitoring and temperature control projects and data logging. Learn how to log the collected data to a microSD card:<\/p>\n\n\n\n You can also publish your readings via MQTT to Node-RED and display your data in charts. We have a tutorial about that subject in the link below:<\/p>\n\n\n\n We hope you’ve found this tutorial useful. If you like ESP32 and you want to learn more, we recommend enrolling in Learn ESP32 with Arduino IDE<\/strong> course<\/a>.<\/p>\n\n\n\n Thanks for reading.<\/p>\n","protected":false},"excerpt":{"rendered":" This guide shows how to read temperature from multiple DS18B20 temperature sensors with the ESP32 using Arduino IDE. We\u2019ll show you how to wire the sensors on the same data … <\/p>\nIntroducing the DS18B20 Temperature Sensor<\/h2>\n\n\n\n
![\"\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2018\/07\/ds18b20.jpg?resize=750%2C525&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\nWhere to Buy the DS18B20 Temperature Sensor?<\/h3>\n\n\n\n
Wiring Multiple DS18B20 Sensors<\/h2>\n\n\n\n
![\"\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2018\/07\/parts_required.jpg?resize=750%2C373&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\n![](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2017\/10\/header-200.png?w=1200&quality=100&strip=all&ssl=1\")
<\/a><\/p>\n\n\n\n![\"\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2018\/07\/multiple_ds18b20_esp32_bb.png?resize=834%2C886&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\nPreparing the Arduino IDE<\/h2>\n\n\n\n
Installing Libraries<\/h3>\n\n\n\n
OneWire library<\/strong><\/h4>\n\n\n\n
OneWire-master<\/strong><\/del> to OneWire<\/strong><\/li>Dallas Temperature library<\/strong><\/h4>\n\n\n\n
Arduino-Temperature-Control-Library-master<\/strong><\/del> to DallasTemperature<\/strong><\/li>Getting the DS18B20 Sensor Address<\/h2>\n\n\n\n
\/*\n * Rui Santos \n * Complete Project Details https:\/\/randomnerdtutorials.com\n *\/\n\n#include <OneWire.h>\n\n\/\/ Based on the OneWire library example\n\nOneWire ds(4); \/\/data wire connected to GPIO 4\n\nvoid setup(void) {\n Serial.begin(115200);\n}\n\nvoid loop(void) {\n byte i;\n byte addr[8];\n \n if (!ds.search(addr)) {\n Serial.println(" No more addresses.");\n Serial.println();\n ds.reset_search();\n delay(250);\n return;\n }\n Serial.print(" ROM =");\n for (i = 0; i < 8; i++) {\n Serial.write(' ');\n Serial.print(addr[i], HEX);\n }\n}\n<\/code><\/pre>\n\t![\"\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2018\/07\/find_addresses_ds18b20.png?resize=785%2C374&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\nGetting Temperature From Multiple Sensors<\/h2>\n\n\n\n
![\"\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2018\/07\/circuit.jpg?resize=750%2C480&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\n\/*\n * Rui Santos \n * Complete Project Details https:\/\/randomnerdtutorials.com\n *\/\n\n\/\/ Include the libraries we need\n#include <OneWire.h>\n#include <DallasTemperature.h>\n\n\/\/ Data wire is connected to GPIO15\n#define ONE_WIRE_BUS 15\n\/\/ Setup a oneWire instance to communicate with a OneWire device\nOneWire oneWire(ONE_WIRE_BUS);\n\/\/ Pass our oneWire reference to Dallas Temperature sensor \nDallasTemperature sensors(&oneWire);\n\nDeviceAddress sensor1 = { 0x28, 0xFF, 0x77, 0x62, 0x40, 0x17, 0x4, 0x31 };\nDeviceAddress sensor2 = { 0x28, 0xFF, 0xB4, 0x6, 0x33, 0x17, 0x3, 0x4B };\nDeviceAddress sensor3= { 0x28, 0xFF, 0xA0, 0x11, 0x33, 0x17, 0x3, 0x96 };\n\nvoid setup(void){\n Serial.begin(115200);\n sensors.begin();\n}\n\nvoid loop(void){ \n Serial.print("Requesting temperatures...");\n sensors.requestTemperatures(); \/\/ Send the command to get temperatures\n Serial.println("DONE");\n \n Serial.print("Sensor 1(*C): ");\n Serial.print(sensors.getTempC(sensor1)); \n Serial.print(" Sensor 1(*F): ");\n Serial.println(sensors.getTempF(sensor1)); \n \n Serial.print("Sensor 2(*C): ");\n Serial.print(sensors.getTempC(sensor2)); \n Serial.print(" Sensor 2(*F): ");\n Serial.println(sensors.getTempF(sensor2)); \n \n Serial.print("Sensor 3(*C): ");\n Serial.print(sensors.getTempC(sensor3)); \n Serial.print(" Sensor 3(*F): ");\n Serial.println(sensors.getTempF(sensor3)); \n \n delay(2000);\n}\n<\/code><\/pre>\n\t![\"\"](\"https:\/\/i0.wp.com\/randomnerdtutorials.com\/wp-content\/uploads\/2018\/07\/temperature_multiple_DS18B20.png?resize=624%2C370&quality=100&strip=all&ssl=1\")
<\/figure><\/div>\n\n\n\nHow the Code Works<\/h2>\n\n\n\n
#include <OneWire.h>\n#include <DallasTemperature.h><\/code><\/pre>\n\n\n\n\/\/ Data wire is connected to ESP32 GPIO15\n#define ONE_WIRE_BUS 15\n\/\/ Setup a oneWire instance to communicate with a OneWire device\nOneWire oneWire(ONE_WIRE_BUS);\n\/\/ Pass our oneWire reference to Dallas Temperature sensor \nDallasTemperature sensors(&oneWire);<\/code><\/pre>\n\n\n\nsensors.begin();<\/code><\/pre>\n\n\n\nDeviceAddress sensor1 = { 0x28, 0xFF, 0x77, 0x62, 0x40, 0x17, 0x4, 0x31 };\nDeviceAddress sensor2 = { 0x28, 0xFF, 0xB4, 0x6, 0x33, 0x17, 0x3, 0x4B };\nDeviceAddress sensor3= { 0x28, 0xFF, 0xA0, 0x11, 0x33, 0x17, 0x3, 0x96 };<\/code><\/pre>\n\n\n\nvoid setup(void){\n Serial.begin(115200);\n sensors.begin();\n}<\/code><\/pre>\n\n\n\nsensors.requestTemperatures(); \/\/ Send the command to get temperatures<\/code><\/pre>\n\n\n\nsensors.getTempC(sensor1)<\/code><\/pre>\n\n\n\nTaking It Further<\/h2>\n\n\n\n