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CumQuaT
12-10-2009, 08:52 AM
Has anyone had any experience in creating a rudimentary oscilloscope using a propeller? I'm trying to measure 36-56kHz signals through an infrared phototransistor (recording remote control signals) so I don't need an oscilloscope that is hugely powerful. A friend of mine has one of the Saleae Logic Probes whick works nicely but I don't want to have to keep bugging him to borrow it.

Anyone have ideas? I merely want to be able to read the signal (pulse durations, etc) in order to recreate them later. Simple enough, but I can't get it to work.

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mikediv
12-10-2009, 08:59 AM
CumQuat I do not know of a prop circuit but if you are interested I have a design for a PIC chip its actually pretty powerful the cost for the whole thing is around 30 dollars the software is free I have not built mine yet but I am in the process of wire wrapping a unit to see how it works if you have an LCD it will be even cheaper since the screen was the most expensive part, also Ebay has a finished product thats pretty nice it basically a big LCD screen that is the whole oscilloscope they cost 50 dollars but its a very nice unit and comes with a probe these are both single channel

CumQuaT
12-10-2009, 09:02 AM
Sounds fantastic. I predominantly work with PICs and have space screens all over the place.

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hover1
12-10-2009, 09:03 AM
Ahh, PropScope:

http://www.parallax.com/Store/Microcontrollers/PropellerTools/tabid/143/ProductID/586/List/0/Default.aspx?SortField=ProductName,ProductName

or Prop specific development, ViewPort:

http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/Viewport/List/0/SortField/4/ProductID/546/Default.aspx


CumQuaT said...
Has anyone had any experience in creating a rudimentary oscilloscope using a propeller? I'm trying to measure 36-56kHz signals through an infrared phototransistor (recording remote control signals) so I don't need an oscilloscope that is hugely powerful. A friend of mine has one of the Saleae Logic Probes whick works nicely but I don't want to have to keep bugging him to borrow it.

Anyone have ideas? I merely want to be able to read the signal (pulse durations, etc) in order to recreate them later. Simple enough, but I can't get it to work.

CumQuaT
12-10-2009, 09:05 AM
Yeah, that's US$250 for overkill. I'm only after a sampling of up to a 56kHz wave with a US$7 prop.

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Oldbitcollector (Jeff)
12-10-2009, 09:11 AM
This isn't a Propscope but maybe it's a starting point software-wise?

Ether way a cool bench tool designed around the propeller.

Propeller Logic Analyzer
http://forums.parallax.com/showthread.php?p=606048

OBC

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New to the Propeller?

Visit the: The Propeller Pages (http://www.warrantyvoid.us/tiki-index.php?page=Propeller) @ Warranty Void.

CumQuaT
12-10-2009, 09:13 AM
Very interesting. This looks kinda of similar to the Saleae Logic Probe. Cheers for the link!

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Ken Gracey
12-10-2009, 09:43 AM
CumQuaT,

The Parallax PropScope is open-sourced hardware (Creative Commons). Have it it! You can even build your own.

The Propeller firmware is not released, but you're welcome to our circuit.

Sincerely,

Ken Gracey

CumQuaT
12-10-2009, 12:00 PM
As awesome as it is that the hardware is open-source (I'm all for that) my expertise with programming propellors is quite limited, so without firmware it's no good to me :(

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Hanno
12-10-2009, 02:15 PM
Have a look at ViewPort, it includes several examples which do exactly what you want. You just need to add one line of code to your program to share the value of the phototransistor with ViewPort. ViewPort then gives you a fully function oscilloscope and logic analyzer to help you analyze your signals- including cursors, auto measurements, triggers, variable timescale- the works. Data can be exported to .txt, .csv, matlab, streamed to an ftp server, and more. 30 day free trial, license starts at $29.
Hanno

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Co-author of the official Propeller Guide- available at Amazon (http://www.amazon.com/Programming-Customizing-Multicore-Propeller-Parallax/dp/0071664505)
Developer of ViewPort (http://hannoware.com/viewport), the premier visual debugger for the Propeller (read the review here (http://www.parallax.com/Portals/0/Downloads/docs/article/ROBOT_ViewPort.pdf), thread here (http://forums.parallax.com/showthread.php?p=760083)),
12Blocks (http://12blocks.com), the block-based programming environment (thread here (http://forums.parallax.com/showthread.php?p=819680))
and PropScope (http://hannoware.com/propscope), the multi-function USB oscilloscope/function generator/logic analyzer

jazzed
12-10-2009, 02:28 PM
The Propalyzer thread offers an interesting alternative :)
http://forums.parallax.com/showthread.php?p=788230

Propalyzer is not a real-time oscope, but it is quite useful.
http://forums.parallax.com/attachment.php?attachmentid=58941
http://forums.parallax.com/attachment.php?attachmentid=0

Post Edited (jazzed) : 12/10/2009 7:34:16 AM GMT

Christof Eb.
12-10-2009, 06:45 PM
Hi,
some time ago I experimented with the combination of ADC820 and the propeller to make a standalone dual channel DSO. You might have a look at PROPSCOPE820:
http://forums.parallax.com/showthread.php?p=622252

The configuration should have enough performance for this.
Good luck
Christof

CumQuaT
12-10-2009, 08:24 PM
Thanks for the ideas! Gives me some things to try on the weekend!

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