Powering 5 sensors with arduino with a single wire

Hi Guys,

I am planning to use 5 DHT22 sesnors with Arduino UNO.

Is it possible to give power to all sensors with one wire?

I want to use also 1 wire for Ground.

Actually my sensors are 5,10,15,20,25 meters away from my Arduino. Thats why i dont want to use power and Ground wires separately for each sesnors. I am planning to use CAT 5E cable.

Thank you.

The maximum cable length can be up to 30 meters / 98 feet if you use 5 V power and 1 meter / 3.3 feet if you use 3.3 V power (see Datasheet).

That was my read taken from here. Their data sheet link does not work. I do know each sensor will need it’s own digital channel and after a run of what you propose I have no idea what the pulses will look like but you are looking at a log run at 25 meters. Personally I don’t see it going well but it may work cries the optimist. I am just not that optimistic.

The subject has come up before here in these forums.


Run data+signal as a twisted pair to each sensor to maintain data integrity, and the supply can be a single extra wire. That could be two CAT5 cables.

It sounds like a real problem. The sensors are not line drivers so expect constant problems. I would suggest you mount each sensor on a PCB or prototype board with a decoupled regulator and power it with 8 or more volts, that will reduce a lot of the noise. Also add a driver chip of some type (differential would be great) to send the data. Before proceeding I would spend a few hours and read the Arduino cookbook by Michael Margolis. Also you will find on line many videos etc showing the Arduino and how to do what you want. This additional information will go a long way in getting your problem solved. Once you get past this you then start on the hardware design and write your software.