So you're a Noob? Post your questions here until you graduate! Don't be shy.

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By mobzero
#76530 Hello guys,

I want to measure temperature and humidity (with DHT11 / DHT22) and send that data to my server. The main request is the low price of the overall project.

The main problem here is that i don't have a power line in the places i want to measure, so i need to run the ESP module with some kind of battery.

Question 1: Is the ESP the right choice to send data, when powered by a battery?
Question 2: Wich ESP module should i use? The basic ESP8266-01, the NodeMCU or even the Wemos d1 mini?
Question 3: Is there any topic where i can find some dates about this?

Thanks for the help guys.
User avatar
By Bonzo
#76590 I ran a Nodemcu with a 1800mAh battery and with tests sending a measurement every 15 min it lasted 8.5hrs - on all the time. Using a deep sleep cycle and waking for 2 min to receive a request and send a signal it lasted 28hrs. If I was not using a pi it would have lasted longer; see below.

With a 2500mAh battery and solar panel it was still going after 46hrs. I took it down as I was having some problems with the pi locking up so the Nodemcu was not going into deep sleep. I am trying to change the code but might give up as having lots of problems and will just put up with the pi sleeping/locking up.

Out of interest I have tried three sensors:
DHT22 - gave up with as it only lasted a week or so in testing using mains power then failed.
SHT15 - better but did not last as long as the BME280 and was the most expensive.
BME280 - cheapest and seemed to use the least power and has a pressure sensor as long as you buy the correct one.