DS18B20 Max Distance from PICAXE

[premelec]

I think this has been discussed before but my search didn't turn it up - what length of 3 wire connection from PICAXE to DS18B20 chip still gives good results on READTEMP12? Assuming a reasonably 'quiet' electrical environment and using common telephone type wire... Thanks...

 

[eclectic]

Was it in this article?

Third paragraph

http://www.phanderson.com/picaxe/ds18b20_08m.html

e

 

[Mycroft2152]

PHAnderson is a great resource for PICAXE info.

Try this:

http://www.picaxeforum.co.uk/showthread.php?t=5178&highlight=ds18b20+length

It is funny I was just looking for the same info this morning. I am building a datalogger to track the runtime of my furnace.

Myc

 

[Michael 2727]

Dallas/Maxim App Notes from the link above -
http://www.maxim-ic.com/appnotes.cfm/appnote_number/148
One Wire Network info, setup and things that you need to know.

A. 200 meters using a resistor pullup,
up to 500+ meters using active pullups (MOSFETs etc), if you are lucky
and the wind is blowing in a favourable direction on that particular day.
(NOTE: All bets are off if you have a 50KW RF or Telco tower within 250m of your house)

1 Meter = 1.09361329833771 Yards for those in less advanced societies
1 Meter = 0.422720017314612 Czech latre.

Read the App notes and followup links and all will become clear.

 

[premelec]

Wow... thanks! and Michael I was hoping for furlongs... after all I'm reading in F deg...

BTW an interesting distributed Dallas network and graphic logger program are described at www.anotherurl.com click on 'solar' - in UK and I love this name! I'm thinking less than 200 feet - perhaps only 10 meters... should work and I have a DS1820 sent to me by mistake that I'll have to see if it's any good for PICAXE interfacing - the DS18B20s are working fine...

 

[boriz]

If that’s not far enough, you could try fibre-optics. I have never needed it, but it sounds like an interesting and probably very Picaxable solution.

 

[jcgalvezv]

A couple of years ago I installed several (almost 8) DS18B20 thermometers around my house all in parasitic power from my laptop computer' rs232 port (using RTS and DTR as power source though diodes + LM78L05 regulator). The more distant was almost 60 meters away. I used phone cable to chain the sensors.