Question 1

Does this include the resistor you'd normally have to wire in with a standalone DHT22?

Accepted Answer

Yes, this does actually include the resistor.  The DHT22 itself is the white part, and has four pins coming out — one of which is not meant to be used.  But in this product, those four pins (including the unused one) are soldered into another board (the black thing you see in the picture coming out of the white thing), which has a couple surface-mounted components, and three open pins for your connections.  One of the surface-mounted components is a resistor with code "512" on it, which translates to 5.1kΩ.  The other is a capacitor, but I can't see any code on it.  The manufacturer of the DHT22 recommends a 100nF capacitor between VDD and GND "for wave filtering".  Anyway, I connect these directly to the 3.3V, GND, and GPIO on my raspberry pi, and it works perfectly without any additional resistor.

Question 2

What would be the maximum length of cable one could use to connect the sensor to a Pi?  I imagine that using 5v would produce a better result.

Accepted Answer

The maximum cable length can be up to 30 meters / 98 feet if you use 5 V power and 1 meter / 3.3 feet if you use 3.3 V power

Question 3

Does the dht library provided by adafruit work with these sensors?

Accepted Answer

I don't know about using adafruit dht library. I use the Troyka DHT library which allows to obtain data of relative humidity and temperature in degrees Celsius, Kelvin and Fahrenheit. Supported sensors: DH11, DHT21, DHT22.

Question 4

When using with a PI2, the sensor became very hot to the touch and had a terrible smell. Is the sensor faulty?

Accepted Answer

Hi, these sensors often overheat due to misconnections. I suggest you check your connections, including jumper continuity. Our sensor modules have a clear pinout silkscreen on them and you need to follow the silkscreen to connect them. If there is a reverse positive and negative connection, a wrong pinout or if the supply voltage is outside the marked voltage operating range, it can cause such problems as you described.

We use original sensors and extremely high quality PCB and components to produce this module, they can only be used by customers if they have passed strict factory tests, and it is the first time we encountered such a problem, no matter what, we will provide you with fast and professional after-sales service.

Do you have an Arduino? Then I suggest you try the simple Arduino DHT tutorial. Power up your Arduino from your computer's USB port. Then see if you can get a real value. This way you can find out if your sensor is good or not. If you still don't get any accurate values, contact me for a replacement.

ASIN	B073F472JL
Additional Features	Portable
Best Sellers Rank	#116,615 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #195 in Temperature Probes & Sensors #1,305 in Single Board Computers (Computers & Accessories)
Brand	Gowoops
Built-In Media	DHT22/AM2302 Digital Temperature Humidity Sensor Module, DuPont wire
CPU Model Number	43221-4105
Color	DHT22*2
Compatible Devices	Arduino, Raspberry Pi, Microcontrollers
Connectivity Technology	USB, Wi-Fi
Customer Reviews	4.4 out of 5 stars 344 Reviews
Display Type	Digital
Graphics Card Description	Dedicated
Graphics Card Interface	Integrated
Graphics Description	Dedicated
Hardware Interface	USB
Human-Interface Input	Buttons
Manufacturer	Gowoops
Model Name	Gowoops Digital Humidity and Temperature Sensor Module
Model Number	43221-4105
Native Resolution	Digital
Personal Computer Design Type	Barebone
Personal computer design type	Barebone
Power Consumption	100 Milliwatts
RAM Type	DDR2 SDRAM
Screen Size	2.6 millimeters
Speaker Description	no
Specific Uses For Product	Business
Style Name	Minimalist
Total Usb Ports	2
UPC	705586405750
Unit Count	2 Count
Wireless Compability	802.11n
Wireless Network Technology	Wi-Fi
Wireless Technology	Wi-Fi

2pcs DHT22/AM2302 Digital Humidity and Temperature Sensor Module for Arduino Raspberry Pi, Temp Humidity Gauge Monitor Electronic Practice DIY Replace SHT11 SHT15

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