How works DHT22?

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RichRich
 
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Joined: Fri Nov 05, 2021 2:07 am

How works DHT22?

Post by RichRich »

Hi, I'm a beginner but have lots of interest in the principles.
I'm doing my project with the DHT22.
I have a question about the principle of the sensor.

DHT22 sends the signal to the MCU in the Digital signal.
There is an Analog to Digital Converter in the sensor.
How does it convert the analog to digital signal?
When I give the 5V power to the part, what's going on after the sensor takes the power?

Please help me to satisfy my curiosity, thank you.

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mikeysklar
 
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Joined: Mon Aug 01, 2016 8:10 pm

Re: How works DHT22?

Post by mikeysklar »

Good question about how the DHT22 works. It is using analog component for the sensors a thermistor (temp) and capacitive sensor (humidity), but it also has a digital chip for the conversion to digital and serial output.

https://learn.adafruit.com/dht?view=all

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rpiloverbd
 
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Joined: Mon Nov 29, 2021 8:13 am

Re: How works DHT22?

Post by rpiloverbd »

Hello,

DHT22 output calibrated digital signal. It utilizes exclusive digital-signal-collecting-technique and humiditysensing technology. Following are some resources that will let you know further about this sensor.

1) Datasheet: https://pdf1.alldatasheet.com/datasheet ... DHT22.html
2)Internal structure, communication protocol and working principle: https://www.theengineeringprojects.com/ ... dht22.html

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