The Open Scope Project
Oldbitcollector (Jeff)
Posts: 8,091
Propellerpowered is committed to continued Open Source Propeller designs and software. We love the freedom that Open Source is providing the Propeller community as a whole and you'll never see a Propellerpowered product that hides it's secrets while we are at the helm!
As many know, the new store stocks many great items desirable by Propeller users, with new items being added every week. Materials are brought in from all over the globe, providing most of you 1-3 day access to items you might have to wait weeks for. (We do the waiting!) -- Also, as a Parallax reseller, we are stocking more and more products from Parallax as well.
One of the new products we are pleased to stock this week is the Propscope! This is a BIG product for us.
The Propscope is an impressive demonstration of what is possible using our favorite micro, that being said, we know the Propscope can reach a level of "insanely great", with some attention from the Open Source community. We don't want to simply stock a product that you can just buy across town, we want to drive it forward!
As the Propscope is put into our inventory this week, we're offering a special price on a limited quantity of Propscopes to those who will join us in the creation of Open Source software which will not only enhance it's capabilities, but also expand it's use in Windows, Linux, and Macintosh environments.
Come join us!
http://propellerpowered.com/forum/index.php?board=8.0
Jeff
As many know, the new store stocks many great items desirable by Propeller users, with new items being added every week. Materials are brought in from all over the globe, providing most of you 1-3 day access to items you might have to wait weeks for. (We do the waiting!) -- Also, as a Parallax reseller, we are stocking more and more products from Parallax as well.
One of the new products we are pleased to stock this week is the Propscope! This is a BIG product for us.
The Propscope is an impressive demonstration of what is possible using our favorite micro, that being said, we know the Propscope can reach a level of "insanely great", with some attention from the Open Source community. We don't want to simply stock a product that you can just buy across town, we want to drive it forward!
As the Propscope is put into our inventory this week, we're offering a special price on a limited quantity of Propscopes to those who will join us in the creation of Open Source software which will not only enhance it's capabilities, but also expand it's use in Windows, Linux, and Macintosh environments.
Come join us!
http://propellerpowered.com/forum/index.php?board=8.0
Jeff
Comments
We are offering a limited quantity of Propscopes at a reduced price ($49.99) for those who will commit to join us on this project. If you have a Propscope already and are willing to join us, we welcome you. We've already turned up some great starting points.
/end recruitment speech.
Jeff
I'm again humbled, amazed, and privileged by the caliber of people who surround the Propeller. Here's why.
When we created the "Open Scope" project, I committed to putting a limited quantity of Propscopes on sale at Propellerpowered at 25% of their retail price. The concern I has was that these scopes might not last more than a day or two, maybe a week, and we would see only two or three people take the "commitment" we are asking seriously, and the bulk of them would find their way to normal scope use, just at a reduced price. In fact, when planning this project, we actually went forward figuring this was part of the cost, and that it would still be worth it.
Then you guys surprised me again...
1) The shelf I dedicated to holding these specially committed Propscopes is still half full this morning.
2) The scopes that have been received have people already working on the project. In spite of the busyness of the holidays.
The Propscope will be taken from "great" to "insanely great" very soon. Expanded capabilities, and Open Source multiplatform support will benefit the entire community.
There are still a few slots open in this project, and if you can lend a hand everyone else has left the opportunity open.
You guys amaze me. Thank you for allowing Propellerpowered to be part of this awesome community!
Jeff
Will your scope have the ability to opperate as a true "Digital Sampling Oscilloscope" as well as the more conventional DSO, Digital Storage Oscilloscope.
It seems to me that from the block diagram your basic circuit is a Digital Storage Oscilloscope not a Digital Sampling Oscilloscope.
Anyway I'm trying to find out it you really are doing a Sampling scope or just a Storage Oscilloscope.
If you are making a Sampling scope why isn't it rated to say 1GHz or more?
There is a cool Design Idea on a Sampling head.
1-GHz Sampling Oscilloscope Front End
Duane J
I talked to jeff this morning about some ideas I had for the scope, I will be making a detailed post on Propeller Powered with my intentions but basically I plan to do convert a board I built specificaly for a prop based logic analyzer to a module for the scope. At first it will probably just use propalyzer, but I have much bigger plans than that, but im counting on people writing open firmware and software to make my vision of intergation come to life.
I dont know anything about scopes, but im hoping this prop scope will be a good gateway, and im also hoping it will help me male the LA module faster, and my mixed signal power supply better since I will hopefully get to see what my decoupling efforts bring to the table. I plan on giving the propscope book a good read. My question to you is, This is just a plane old Parallax Propscope.. can the hardware acually sample at 1ghz+??? Its just a couple adc082(that may be the wrong chip#) connected to a propeller. Can higher capture of digital/analog signals be achieved without altering the scopes front end, maybe just adding some memmory and writing better software? Im also not sure but doesnt the scope use an ftdi in which case the serial connection to the pc would be a limiting factor in speed?1
@Jeff: So would it be bad form (in the true spirit of Christmas) to buy up your remaining stock and flip 'em on Ebay for 300% markup? I mean, there's plenty of shopping time left before Christmas...
JK. Glad to hear (but not surprised) that you're getting quality help from high-caliber Forumistas. Wish I had time to participate, but I'm so far backlogged with projects that I can't even remotely see the light at the end of the tunnel. If the world ends tomorrow, I'm hosed!
Sampling scopes operate a bit differently than DSOs.
A sampling scope takes 1 sample of the signal for each waveform passing by. They require the waveform be repetitive and fairly stable.
There are basically 2 types of samplers.
1. Delayed Sampler. After the trigger there is a delay before the sample is taken and held for the AtoD. Each waveform is sampled at an increasingly later delay until the whole waveform is done. If 256 data points are needed there are 256 different delay times.
2. Frequency Sampler. First the exact frequency of the waveform repetition rate is measured, F. Then, if 256 samples are desired, take samples at a rate of 255 / 256 * F. One waveform will have been sampled.
The interesting thing is the AtoD doesn't have to be particularly fast as the rate the AtoD operates, in these examples, is 1/256th the rate of the waveforms. Very cool.
A sampling scope has limitations, the waveform must repeat, but the bandwidth can be much faster than the raw speed of the AtoD. I expect it would not be to hard to get 1nS sample times or even faster.
Most of the hardware is already in the PropScope. The sampling head is added to do the fast analog sample and hold. Then the DSOs AtoD reads the analog value and displays it.
This is a reasonable example of a 1-GHz Sampling Oscilloscope Front End sampling head. I expect the Prop with its nice counters can do most of the timing so I think Frequency Sampling is particularly suited to the prop.
I hope I explained this well. Any questions.
Duane J
Like I said i have never had the pleasure of using a scope but need one badly and I figured the propscope would be an awesome beginner scope, and the OpenScope project could hopefully help the scope grow with my needs. At this point in time I basically just want to develop for the prop scope and use it to make sure im running clean square waves and not having power or noise issues.
The PropScope is a Digital Storage Scope, DSO.
Sampling scopes are much faster. No, since transients are not repeating waveforms you nead to use a storage scope. The sampling scope needs repeating waveforms. Transients by there nature are not repetitive. -> Storage.
However, things like fast rise times with overshoot and ringing are repetitive. -> Sampling with fine resolution.
In my former life I had a really fast 8GHz LaCroy storage scope. Very cool! If you put a few dimes in a polystyrene plastic box and shake it you get all kinds of spikes up to 100V a few feet away. Really scarey stuff! Thank goodness the Prop is to slow to see this.
And our 30GHz sampling scope can't see this either because it wasn't repetitive.
Duane J
That is nuts about the plastic box!! of course that is all voltage and almost no current right?
It's the energy level that's low as the pulses are only Pico Seconds in length.
Jeff,
Any view on what cross-development system should be used for the project? Working with Qt (QT Creator) on SImpleIDE seemed productive...
I'de like to help in building the open-source project from the Mac OS X perspective!
dgately
Now as a member, i fell comfortable in saying NO, NOT JAVA!!! Some folks are very adverse to loading the Sun/Oracle JVM on their machines much like .Net or Mono infestations are frowned upon.
I was thinking along the line of Mr. Gately, Qt seems to have proven itself with SimpleIDE for cross-platform projects.
Also, I support using Qt.
Also, Oracle is a big issue here. Their legal department doesn't seem to understand what it means to be a steward of a specification, and their lawsuit against Google is quite well-publicized. To that end, they have proven that almost any company that uses Java is opening themselves up for a legal attack due to nitpicky licensing. Also, I prefer to keep a Java VM off my computer if possible. (haven't managed it yet, though).