General area when it fits no where else

Moderator: Mmiscool

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By ardhuru
#53552 Hello all,

I have been using a DHT11, and the temperature readings seem to be fairly accurate. The humidity reading, on the other hand, is way off from what Google tells me it should be for my city.

After a lot of searches, I found a number of patches/solutions. I would love to have some opinions on these.

1) The sensor works better at 5 volts, rather than 3.3. At 5 volts, the humidity sensor seems to give fairly good readings (I have not tried this, just quoting what I learnt). Fine for the Arduino folks, but with an ESP I guess if you power it from 5 volts, you'll also need to do some level shifting while feeding the output pin to the ESP.

2) This, however crude, really seems to bear out; just add 20 to the humidity reading from the DHT, to give the actual value. There's no explanation for why this is so, but seems to work spot on, at least for the current values in my city.

Ant thoughts, suggestions guys?

Regards.
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By Mmiscool
#53698 You can safely power the sensor with 5v as long as the esp is still powered with 3.3v.

The input pins are 5v tolerant. Hope this helps. If you have a NodeMCU module the VIN pin will provide you 5 volts when plugged in to USB. I have found that those little wall warts are great power supplies for esp8266 based project. Just plug a USB cable to the module to power it.