Hello, I am working on a project involving the NodeMCU ESP8266 12e board and 6 IR proximity sensors. My plan was to power the sensors through the vin pin while the board is plugges into USB. While it works sometimes, it is not consistant at times. Also some pins the sensors that are plugged in seem tl glitch and read constantly as if something was there. I believe it to be a power issue, but I am un sure what to do. I thought of getting a 12v to 5v converter and split the power between the board and the sensors, or should I power the board and use the VIN pin to power the sensors?
That can't possibly work. Vin does never provide any power.
What current will rhe sensors draw? In general, controllers are not ant power supplies.
Please make a little schematics showing the build.
V-in of a NodeMCU ESP8266 is connected to USB power through a diode.
You can power sensors form that pin.
The common IR proximity sensors with a 5mm LED and a 5mm phototransistor draw about 30mA for the IR LED and a bit more for the receiver part. I guess about 40mA total.
6 sensors plus the 400mA peaks of the ESP could indeed give problems.
Leo..
Thanks for telling! That means USB "+5" minus 0.7 volt is available. 4.3 volt or likely even less. At 400 mA...... I wouldn't go for it.....
After listening to all there replies I came up with this little schematic. The idea is to use my 12v wall plug and plug it into a dc jack port. Then have it be split between the board and a 12v to 5v step down going to the sensor. I see my issue with trying to use the board as a power supply now, thank you.
Doesn't the esp Vin accept 5 volt? That would create less heating on the esp board I think.
It doesn't 'accept' 12V -- that's for sure.
It is labeled as 5 volt, but I read some people using the 12 volt plug with it which I already have. I can use 2 step downs then and have both the board and the sensors running on 5 volts.
You can but that's overkill. Use one 12 to 5 volt converter having enough current capacity.
Note the reply from @anon85221860!
Thank you for the confirmation! I will avoid that all together and just use the drop down for the whole thing then.
Will do, thank you for the help!