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I'm quite new with the electronics part of Arduino, but I thought that this was the basic way to get the DS18B20 temperature device hooked up. However, I can't detect it in my program using OneWire and DallasTemperature.

This is an image of my connections:

enter image description here

Basically my approach was like this:

Connect ground on ground on the DS18B20. Connect 5V from the Arduino to both DQ from the DS18B20 and Port 2 on my Arduino (the two yellow cables). Between the 5V and the two yellow cables, I connected a 4.7K resistor. Vdd on the DS18B20 is not connected to anything.

Anyone have any idea why this is not working as expected for me?

Thanks in advance!

Øyvind Bråthen
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1 Answers1

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Vdd on the DS18B20 is not connected to anything.

According to the datasheet:

When the DS18B20 is used in parasite power mode, the VDD pin must be connected to ground

Connect 5V from the Arduino to both DQ from the DS18B20 and Port 2 on my Arduino (the two yellow cables).

That means port 2 would always be high, right?

According to Temperature Sensor DS18B20 this is the wiring for non-parasitic power:

Non parasitic power

If you want the two-wire version (parasitic power) it would be:

Parasitic power

Nick Gammon
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