59iosl30
Posts: 11
Joined: Mon Apr 25, 2016 10:49 am

DS18B20 1-Wire digital thermometer on speaker cables

Wed Nov 02, 2016 9:00 am

Hello!

Is it possible to use the DS18B20 in parasite power mode with approximately 25 meter speaker cables (which are already placed in the wall to the other rooms)?

Is there anything which I should consider in order to be safe?

Does anybody have experience with 1-wire bus on speaker cables?

Thank you!

59iosl30
Posts: 11
Joined: Mon Apr 25, 2016 10:49 am

Re: DS18B20 1-Wire digital thermometer on speaker cables

Sat Nov 19, 2016 11:45 am

Does nobody else here tried to connect the DS18B20 with speaker cables ?

Major Tom
Posts: 65
Joined: Wed Feb 03, 2016 8:13 am
Location: Strung up in heavens high.

Re: DS18B20 1-Wire digital thermometer on speaker cables

Sat Nov 19, 2016 12:55 pm

I have never tried the GPIO 1-wire interface in parasitic mode. I usually use three wires- 3.3V, data and GND. But this guy seems to have it working:
https://www.mkompf.com/weather/pionewiremini.html

You could easily try it and see how you get on.
My circuit's dead, there's something wrong.

mcummings
Posts: 8
Joined: Wed Oct 19, 2016 1:27 pm

Re: DS18B20 1-Wire digital thermometer on speaker cables

Mon Nov 21, 2016 2:53 pm

I've done a fair amount of work with the one wire interface, specifically the DS18S20 (the DS18B20's predecessor) in production environments. I tried long and hard to avoid having to run power to the device and just power them parasitically using current derived from the serial port, but in the end it just wasn't reliable enough and I added my own tiny power source. What I found was that the capacity to power parasitically was entirely dependent upon the computer to which the device was connected, which makes sense actually. For my environment (hundreds of deployed devices) I could just not take the risk.

If you're just trying to make this go for a one-off situation, then I'd say you have a 50/50 chance - either it will work reliably or it won't!

Let me know if I can be of any further assistance.


Respectfully,
Marshall

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