DIY Temperature & Humidity Meter with ESP8266 & DHT22 module


I'm going to be using the above guide to make 3* temperature & humidity meters that would send me text+email alerts, and will modify it so that I can view the temp/humidity in real time over my home network, probably using thingspeak if I cant find a better solution.

Once done, I will edit this post with a text based tutorial & a copy of the final code (ETA 1 month)

The limitations of the original tutorial is that it only gives text+email alerts, thats good if you want to save power, but as mine is mains powered I want it to be accessible over the network. I may need to add on another cheap component to do this. Also, the original tutorial uses a DHT11 module which has poor humidity accuracy. I will be using a DHT22 module which is better for measuring humidity.
 

klx

Well-Known Member
Its cool tech but what use do you have for text and email alerts? There are lots of (free) options around that will switch your fans, AC etc on/off based on your temps and humidity. You just need the software (Eg Home assistant, Mycodo) and some relays.
 
Its cool tech but what use do you have for text and email alerts? There are lots of (free) options around that will switch your fans, AC etc on/off based on your temps and humidity. You just need the software (Eg Home assistant, Mycodo) and some relays.
yeah there is prob a better solution like push notifications that i need to look into, the text+email alerts are just whats included in the guide, they do it that way to save power (viewing it over the network would need more power). re controlling fans through humidity, ive got some smart plugs to do that, but right now as its my first time using em i dont trust the cheap humidity sensors enough to control my fans, what if it spits out some random value causing the fans to stop working?

the way i plan to do it is to just let it send me notifications (or monitor it over the network), then check the grow camera and see how everything is doing, then if needed i can turn on/off the fans manually.

once this first bit is done ill definitely do what you say though and use the DHT22 to control the smart plugs using home assistant to maintain a certain humidity, thats the best way it shouldnt be difficult :)
 
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klx

Well-Known Member
yeah there is prob a better solution like push notifications that i need to look into, the text+email alerts are just whats included in the guide, they do it that way to save power (viewing it over the network would need more power). re controlling fans through humidity, ive got some smart plugs to do that, but right now as its my first time using em i dont trust the cheap humidity sensors enough to control my fans, what if it spits out some random value causing the fans to stop working?

the way i plan to do it is to just let it send me notifications (or monitor it over the network), then check the grow camera and see how everything is doing, then if needed i can turn on/off the fans manually.

once this first bit is done ill definitely do what you say though and use the DHT22 to control the smart plugs using home assistant to maintain a certain humidity, thats the best way it shouldnt be difficult :)
Sounds like a plan mate

They do fail from time to time the cheap sensors but unless you are running them in 90% plus humidity environments they are pretty good. You might enjoy this vid if you are keen on diy automation -

 

Mak'er Grow

Well-Known Member
The DHT sensors have problems like stated above, but over all they do work fairly well in the average setup.
I switched to the BME280...it does pressure, humidity and temperature on I2C or SPI.
Good luck on your adventure and happy growin' :P
 
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