Weather-Watch.com

Weather Equipment/Software => Home Built/Kit Weather Stations/Sensors => Topic started by: JohnnyBoy on December 31, 2017, 02:12:15 PM

Title: Owon Scope and 1Wire
Post by: JohnnyBoy on December 31, 2017, 02:12:15 PM
Hello,

Does anyone here have a Owon Scope and a 1-wire system that they have looked at with the scope.
I say because I'm not 100% sure the scope is up to the job, bandwidth, It's only a 100MHz, a (SDS7102V)
So what is happening when the timebase is slowed down, not all the signal is going to 0(Zero)Volts, say 1 volt. But very random. See attached images.

John
Title: Re: Owon Scope and 1Wire
Post by: JohnnyBoy on December 31, 2017, 02:14:01 PM
Another image.. as limited to 512k per post
Title: Re: Owon Scope and 1Wire
Post by: JohnnyBoy on December 31, 2017, 02:15:24 PM
Last image
Title: Re: Owon Scope and 1Wire
Post by: niko on December 31, 2017, 02:54:29 PM
I think the scope is fast enough. Is that a real 1-wire network with e.g. long wires out in the yard, or just a bench test?
Title: Re: Owon Scope and 1Wire
Post by: JohnnyBoy on December 31, 2017, 03:08:27 PM
Hello,

Yep that's the full weather station, 30 mtrs or there abouts... with 12 devices on it.

John
Title: Re: Owon Scope and 1Wire
Post by: niko on December 31, 2017, 03:42:33 PM
In that case, unless there is a functional problem, I wouldn't worry about it. If you just connected a couple of chips on the bench it would look a lot cleaner. 1-wire is designed to work well with less than optimum conditions/cheap wiring/external noise. The bus doesn't have to be zero volts for the chips to recognize a logical zero, on the 1-wire data sheets I looked at it is specified as anything below 0.8 volts.
Title: Re: Owon Scope and 1Wire
Post by: JohnnyBoy on December 31, 2017, 03:55:26 PM
Hello,

It's working a lot better than a couple of days ago.. two diodes on two sensors (hobbyboards) had died, they were certainly making a mess of the bus, however, that's why I have taken a more deeper look into the bus signals. I'm still not 100% convinced the scope is good, it is the first digital scope I have owned.

I will have to do some more tests..

John
Title: Re: Owon Scope and 1Wire
Post by: niko on December 31, 2017, 04:15:36 PM
I have a Rigol. It's nice to have the memory function and be able to grab screenshots but realistically it is what it is, a cheap 'scope, and can't really be compared to my analog one that cost close to $2K quite a long time ago.