This feature can be a huge advantage when you want to control many DS18B20s distributed over a large area. To know how to read temperature from multiple DS18B20 temperature sensors, please check this tutorial out. As each DS18B20 has a unique bit DQ is 1-Wire Data Bus should be connected to a digital pin on microcontroller. VDD pin supplies power for the sensor which can be between 3. The connections are fairly simple.
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Chainable, it is possible to chain up to sensors on one cable remember ESPEasy has 12 tasks max No calibration necessary if the tolerance fits your needs as the sensor gives digital data directly. Many forms availlable from bare chip to waterproof and tube sensors.
Every DS18B20 has a unique adress burned in at production time. The sensor needs a pull up resistor. If you use the breakout board type the resistor usually is already on the board.
This gets you into problems if using several DS18B20 breakout boards- As there should be only one resistor on the whole line you might have to remove resistors leaving just one at one end of the line. Cabling: Do not use very thin cabling!
The preferred structure is a straight line. If possible avoid "stubs". If necessary it can be cabled in a "star" infrastructure. But be aware that stubs and star form reduce the possible cable length. Hardware Connecting the DS18B20 is done easily.
Just connect it as shown in the schematic: As you can see the sensors are just lined up, no aditional "trick work" necessary. There is no device address at this time, they will show up later. Additional setting Device resolution: The device resolution can be set. The lower the resolution the accuracy decreases and the speed increases. As temperatures do not change very fast usually a high accuracy can be choosen without problem.
Submit the settings to the ESP. Now the Device address field shoud get alive. If you have only one DS18B20 connected just chose the single address shown and submit. Remeber you have to setup a task for every single sensor on the line. They have all same settings besides the device address and name. Now it should like this in your device list: Too late - all DS18B20 installed And now it gets confusing.
Which address is which sensor? A simple trick helps out. Now take one sensor between your finger tips for half a minute and watch the values. One value should raise as your fingers usually are more warm the the air around. Now you may name it to a meaningfull name like "Livingroom" or whatever. Calibrating See "Basics: Calibrating" for further information [link] Hints To be breadboard checked, not tested yet. Can the plugin handle that? If you need a star infrastructure or stubs or if you need just longer cabling there is a way out.
One line runs on one GPIO. If the cabling gets too long or you have too much stubs or star cables try to split into two circuits. Troubleshooting Usually the DS18B20 works without issues. With long cabling you might get wrong data sometimes. It might be helpfull to reduce the resistor a bit, 2,2 KOhm is lowest possible. If nothing works disconnect all sensors from line and connect back one by one, checking every time. Cable may be too long or too thin for the given distance.
Keep cabling away from other cables to avoid interferences.
You can use the preceding links or go directly to MakerAdvisor. Schematic The sensor can operate in two modes: Normal mode: 3-wire connection is needed. You provide power to the VDD pin. The sensor derives its power from the data line. Follow the next steps to install those libraries. Installing Libraries 1.
ESP32 and DS18B20 temperature sensor example
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Arduino - One Wire Digital Temperature Sensor - DS18B20
Interfacing DS18B20 1-Wire Digital Temperature Sensor with Arduino