Digital Thermometer with DS18B20
Read a DS18B20 one-wire probe and show the temperature on an LCD.
Overview
The DS18B20 reports temperature as digital values over a single wire, so readings stay accurate even on long leads. A 4.7 kΩ pull-up is the only extra part.
Build Steps
Wire the one-wire bus
Data to a digital pin with a 4.7 kΩ pull-up to 5 V; power from 5 V and ground. The TO-92 pins are GND, data, VCC from left to right flat side facing you.
Read the sensor
Use a one-wire library to start a conversion and read the 12-bit result; divide by 16 for degrees Celsius.
Show it on the LCD
Send the value over I2C to the 1602; run an I2C scanner first to confirm the backpack address.
Check accuracy
Compare against ice water (0 °C) and warm tap water, and average a few readings to steady the last digit.
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