The DS18B20 is a single-wire waterproof digital temperature sensor invented by Dallas Semiconductor. So it is available in Stainless-steel probe form and has characteristics like high precision, small size, strong anti-interference ability, low hardware overhead, etc. Thus, this temperature sensor is ideal for measuring temperature in different conditions, such as underwater, wet conditions, something far away, or under the ground.
 
This temperature sensor measures a wide temperature range, from -55°C to +125°C (-67°F to +257°F), with +-5% accuracy. So, this sensor uses a single-wire bus protocol to communicate with a microcontroller and transmit the temperature readings. Thus, its resolution ranges from 9 bits to 12 bits, but the default resolution to power up the temperature sensor is 0.0625°C precision, i.e., 12 bits.
How DS18B20 Temperature Sensor Work?
The DS18B20 waterproof temperature sensor works similarly to a temperature sensor. So it measures temperature and ADC conversion with a convert-T command. So the output temperature value can be stored in the 2-byte register in the sensor and later, it returns to its stationary state. This temperature sensor includes three wires or pins like Vcc, GND & data wires mainly for operation.
 
DS18B20 digital temperature sensor provides temperature measurements that range from 9-bit to 12-bit Celsius. Thus this sensor can also have an alarm function including nonvolatile user-programmable lower and upper trigger points. This sensor communicates above a 1-Wire bus that needs one data line only for communication through a central microprocessor. So this sensor additionally derives power straight from the data line by removing the need for an exterior power supply.
So every DS18B20 sensor includes a unique 64-bit serial code that allows several DS18B20 sensors to work on a similar 1-Wire bus. Thus, it is very easy to utilize one microprocessor for controlling several sensors that are distributed above a large area.
DS18B20 Pin Configuration:
The DS18B20 temperature sensor pin configuration is shown below. So this sensor includes three pins which are explained below.
             DS18B20 Pin Configuration
Pin-1 (GND): This is the Ground pin of the temperature sensor, so connected to the microcontroller’s GND terminal.
Pin-2 (VCC): This is the power supply pin of the temperature sensor so connected to the 3.3V/5V terminal of the microprocessor or microcontroller.
Pin-3 (DATA): This is the o/p pin of the temperature sensor that provides the output with one wire method. So it must be attached to a digital pin on the microprocessor or microcontroller.
Features & Specifications:
The features and specifications of the DS18B20 temperature sensor include the following.
DS18B20 is a digital temperature sensor.
This sensor is available in different packages like 8-Pin SO, 8-Pin µSOP & 3-Pin TO-92.
Its unique 64-bit address allows multiplexing.
It doesn’t need external components.
This sensor needs two pins only for operation in parasitic power mode.
Several temperature sensors can share a single pin of microprocessor/microcontroller.
It includes programmable alarm options.
Its unique single-wire interface needs a single digital pin of microprocessor or microcontroller only for its communication.
Its accuracy is ±0.5°C
This sensor’s resolution is 9- bits, 10- bits, 11- bits, (or) 12-bits.
Its operating voltage ranges from 3V to 5.5V.
DS18B20 sensor includes an alarm feature with low and high user-settable temperature thresholds
These sensors are waterproof, so used in moisture-exposed environments.
It communicates through a 1-Wire bus that requires only one data line used for communication.
Each DS18B20 sensor has a unique 64-bit serial code that allows several DS18B20 sensors to work on a similar 1-Wire bus.