Connecting myRIO with DALLAS 18B20 temperature sensor

[Shoura]

Hi there,

I am new to the NI myRIO. 

And I got a problem right at the beginning. I want to connect my DALLAS 18B20 temperature sensor with my myRIO.

It is a 1-wire interface sensor and it provides digital temperature measurements.

What I finnaly want:
I want to read out the temperature from the 18B20 and show it on the Frontpanel as a thermometer in real-time.

My Problems:

How do i have to connect this sensor?

How to get the data, it is "sending"?

My german is better than my english, so feel free to answer in german 😄

Thanks for your help!!

[jSturm]

Hello Shoura,

maybe this would help you out

OneWire Utilities - Interface Innovations Toolkit and Applications for Maxim 1-Wire Devices

http://sine.ni.com/nips/cds/view/p/lang/en/nid/211522

[Shoura]

Hi jSturm,

Thanks for that. Looks pretty nice, but it does not work 😞

I don't know, what I am doing wrong.

Let's try it step by step.

Where do I have to connect the DS18B20?

I connected it on the right side of myRIO at 5V, DGND, DIO7 (Picture will follow!)

Is that correct?

I just did this yesterday and put an myRIO-Digital-Input in my LabVIEW programm. The return of this Input is always "TRUE" if the programm runs.

[JuliaO]

Hello Shoura,

you want to connect it like in datasheet figure 5?  
Did you also use a pullup resistor 4.7 as you can see in the picture?

Regards, Julia

[Shoura]

Hi Julia,

For me, it doesn't matter, how it is connected 😄

If it works, it's fine 🙂

At the moment the sensor is connected directly to myRIO.

At the end I just want to have kind of a thermometer. (I will post a picture today)

[JuliaO]

And what about the pullup resistor?

Here you can see how to connect it:
http://fluuux.de/wp-content/uploads/2012/09/Pinbelegung_ds1820.png

[Shoura]

So i need this pullup resistor?

I did it just like you can see at the picture 🙂

And as I said, if I put a Digital Input (found at myRIO palette) in my LabVIEW programm, I get TRUE as an answer. If i take the sensor away, the answer is false.

[Andi.G]

Hi,

Yes you need this pullup resistor 

Regards,

Andi

[Shoura]

Ok.

The pullup resistor is set between the sensor and his former slots (like you could see in yesterday`s picture).

So this setup is ok?

Or anything else to change?

[Andi.G]

Hi Shoura,

please set it up like you can see at the following picture:

When you do this it should work fine.

Regards,

Andi