LCD and ds18b20 voltage drops?

Projects General Guidance
1

Hi there,

I'm making an oil and engine bay temp sensor for my camper van

Consisting of 2 temp sensors (ds18b20), Arduino uno and a 16x2 lcd.

I have the actual setup working fine in my test area, however

In the van, there is approx. 3.5 metres in distance from where the sensors are and where the lcd needs to go.

Now, in the name of distances would it make more sense to have the Arduino and lcd together and 3.5m leads to the temp sensors

Or

Have the temp sensors and Arduino next to each other then the 4 lcd (ic2) wires 3.5 metres in length to the front of the van?

I ideally don't want to entertain Bluetooth etc as its a fairly nice and simple system to start. With the temp sensors being digital reading, would the voltage drop not bother these as much as the lcd?

2

DS18B20 can be bought with 5m cable, so I guess that says quite a bit. They can also run on 3v. A bigger problem is unshielded cable picking electrical nasties.

3

Hi,
I'd keep the Arduino and LCD together..

1-wire communications is 3 to 5V and so has decent noise immunity. Thousands of "waterproof" DS18B20s like THESE are used in industrial systems without problems.

In a truly intense electrical noise environment, you could add a braided metal shield (grounded back at the Arduino) . You'd want to insulate the outside of that if it could contact any metal, which would cause ground loops..

I run the longer cables around the house, outdoors and to the swimming pool without problems..

DISCLAIMER: Mentioned stuff from my own shop...