I want to build a temperature sensor unit with dth11 and nodemcu to send data to cloud. I was able to do it while the nodemcu was connected to my laptop. Now i want to use battery so that i can do a compact unit. Can someone please help me understand if i can use commercially avl battery units
nodemcu is just firmware. What ESP board did you use? How was it connected/powered from the laptop?
Of course you can use commercially avl batteries,the question is what voltage your esp8266 board accepts and what amperage it needs
iotenthu:
I want to build a temperature sensor unit with dth11 and nodemcu to send data to cloud. I was able to do it while the nodemcu was connected to my laptop. Now i want to use battery so that i can do a compact unit. Can someone please help me understand if i can use commercially avl battery units
How does this relate to Arduinos?
Hi, you can probably use 3 or 4 NiMH cells, AA or AAA size, or li-ion cells in a variety of sizes such as 10440 or 18650.
With batteries, your sensor will only run for a few hours unless you make use of the ESP's deep sleep mode, in which case batteries can be made to last many weeks.
Here are some sensors I built using Wemos D1 mini which are similar to NodeMCU boards.
Paul
All of the NodeMCU's I have from various sources have the 5V for USB and they have a 3.3V regulator on the board. The output of the regulator, 3.3V, appears on one board pin (on my Lolin, actually on 2 pins both labeled 3V) You can use a single LiFePO4 to run this board. Or you can use regular alkaline batteries (4xAA) and a DC-DC "buck" voltage module.
The DC-DC bulk can easily handle the ESP8266 and the cost is around $1 U.S.D.
Another option is those cheap cellphone Lithium batteries that have the USB connector. Just USB to USB and use the board internal regulator.