Arduino humidity sensors: testing and calibration

Three sensors have ability measuring 20-80% RH with accuracy +/-3%
SHT21 and DHT22 are sensors for measuring humidity and temperature.
BME280 is sensor from well-known maker Bosch, for measuring atmosphere pressure, humid and temperature.
This video will show test result of those 3 sensor to check which one is the best one. However, none of them are correctly. We need to calibrate it with simple things.
After make sensor correctly, then we can use it to measure humid and temperature of room, view via internet by Blynk software
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Code and circuit
https://bit.ly/2KMoryB

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1. BME280 https://amzn.to/3xTrvzR
2. DHT22 https://amzn.to/3gNdDjw
3. SHT21 https://amzn.to/2VKj6hE
4. Arduino UNO https://amzn.to/3zKAQLV
5. NodeMCU https://amzn.to/2PPo5e0
6. Humid meter https://amzn.to/2xURzho
7. Thermometer probe https://amzn.to/3aIykId

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Other meaning project made by me:
1. Shadow light box http://bit.ly/2rtcrMN

2. DIY Portable infrared thermometer http://bit.ly/2M0NOhx

3. Temperature indicator http://bit.ly/2E5EhBl

4. How to program OLED screen http://bit.ly/2E7Q5mH

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