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DHT11 Discussion Notes

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I have a DHT11 module that looks exactly like the image below. I also have raspberry pi zero wh.

  • I have connected 3.3V (pin1) to the + on the module.
  • GND (pin6) to the - on the module.
  • I was carefull never to connect anything to 5V

Unfortunately this stops my raspberry from turning on. It doesn’t matter if I connect the data cable or not. As soon as those two are connected the power led does turn off. If I try to connect them while the raspberry is on it immediately shuts off. (power led goes off, ssh connection is lost) Am I doing something wrong, or do I maybe have a faulty sensor module here? How do I even start to check for that?

enter image description here

Other side of the module: back of module

enter image description here

 New contributor
  • 1
    I didn’t look at your picture (I am not about to download ANY file) – but this is unlikely to help. Paste any info ito your Question.Tell us WHAT module and HOW YOU connected it. Your description is unclear. PS try writing in paragraphs. – Milliways 2 days ago
  • 2
    @Milliways thank you for the comment. I have tried to make my question clearer. Is there anything that is still unclear? I don’t know if the module has any specific name. The store that I have this from only labels it as “dht11 module” and doesn’t provide any datasheets unfortunately. – blues yesterday
  • 1
    @tlfong01 I am aware of this and I was very careful to never even touch any of the 5V pins while setting this up. When you say there is “a couple of fatal newbie traps”, what others are there that could cause these symptoms? – blues yesterday
  • 1
    You need to provide a clear photo showing the connections you have made between the Pi and the device. – joan yesterday
  • 2
    It looks like you have a faulty DHT. It seems likely the + pin is shorting to the – pin which will cause a short and cause the Pi to try to reboot. Get a new DHT. – joan yesterday

3

Answer

As per the comments of @joan and @theashwwanisingla I tested the module/sensor and there is 0 resistance between the + and - pins. So this is simply a broken piece of hardware.


References

(1) DHT11 Temperature and Humidity Sensor User Manual – Components 101 2018jan05

(2) DHT11 Temperature and Humidity Module Datasheet – AoSong

(3) DHT11 Setup Tutorial – Circuit Basics


Appendices

Appendix A – Internal circuit of DHT11

dht11 internal circuit

 New contributor
  • Sorry to hear the bad news. The short is usually due to bad workmanship. You might like to check to see if the short circuit is caused by bad soldering. Sometimes you can use a hobby knife to fix it. By the way, the following product advert has a DHT11 datasheet a the end. Reference: (1) “DHT11–Temperature and Humidity Sensor – Components 101 2018jan05”: components101.com/dht11-temperature-sensor. Good luck and cheers. – tlfong01 yesterday    
  • Hi @blues, I have taken liberty to add to your answer a reference list and the internal circuit of DHT11. As suggested above, you might like to use a multi-meter to check out any short circuit due to bad soldering. BTW, other newbie traps or mistakes are just careless mistakes, like wrong polarity of power supply, wrong pin outs etc. To avoid careless wiring, I almost always colour code the connecting wires, eg. black for ground, red for +5V, white for +3V3, yellow for signal input to device, orange for output signal from device etc. – tlfong01 yesterday    
  • And I might have misled you by saying that there are a couple of “fatal” newbie errors. Actually I did not meant those errors also kill the DHT11. Rather they “kills” the projects, or at least stalls the project. For example, it is a bad idea to order just one DHT11 for testing or prototyping. Since the device is only one or two dollars, and the express delivery cost for me is four dollars, so I always order at least two, to (1) To spread the express delivery cost, / to continue, … – tlfong01 5 secs ago   Edit   
  • (2) To use the extra devices as spares for pair/swap troubleshooting, cross calibration, etc. R&D guys usually order extras from different vendors to guarantee a “second source” etc. Cheers. – tlfong01 just now   Edit   

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