I see the exact same offset (-.48V, -.49V) in the 10X mode. I'm so used reaching out and turning a knob to fix that, but alas, no knobs.
(Hardware shipped, now we will fix it in software. Worked on Hubble)
Jim
tdlivings said...
Mine arrived yesterday evening.
Assuming no pilot errors on my part as I am just firing it up for the first time
and trying things I have a couple of issues. When I use 10x probe setting I have
an offset on Channel 1. Channel 2 is fine. Also a minor issue is the screen goes wild
when I tried triggering on a 1khz sine wave. Ok if level is switched to Normal.
I attached a pdf with two screen images and some notes above the images.
Page break got me on the second pic.
Also when switching ranges I see the screen garbage for a flash sometimes, that
does not bother me.
I really like what I see of the propscope and it is a real bargan.
I have to get use to setting the trigger as it looked right at times and others I
think I piloted it wrong.
Hi Tom,
Thanks for posting about your first PropScope experience. It's very valuable to get this type of feedback!
The offset when using the 10x setting may be due to probes that need to be compensated- they come with a screwdriver and are adjustable.
The "auto" trigger mode calculates the trigger level from the average of the signal shown on screen. If your timescale is too fast for the signal so that you get less than one cycle on screen, your average will change and the trigger level will jump around. Try switching to a slower timescale- or use the "normal" mode- where you manually set the level.
Yes, the sampling algorithm takes 1 cycle to recover after ranges/timescales are changed.
Hanno
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Co-author of the official Propeller Guide- available at Amazon
Developer of ViewPort, the premier visual debugger for the Propeller (read the review here, thread here), 12Blocks, the block-based programming environment (thread here)
and PropScope, the multi-function USB oscilloscope/function generator/logic analyzer
Getting the PropScope software right should be easier than fixing the Hubble! And unfortunately the Hubble Hardware had a problem, the mirror was ground very, very precisely- but to the wrong shape. And sadly, that couldn't be fixed in software- they had to fly "glasses" up.
Hanno
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Co-author of the official Propeller Guide- available at Amazon
Developer of ViewPort, the premier visual debugger for the Propeller (read the review here, thread here), 12Blocks, the block-based programming environment (thread here)
and PropScope, the multi-function USB oscilloscope/function generator/logic analyzer
I believe the variable cap in the probe is only going to do frequency compensation. It had no effect on offset.
Jim
Hanno said...
Hi Tom,
Thanks for posting about your first PropScope experience. It's very valuable to get this type of feedback!
The offset when using the 10x setting may be due to probes that need to be compensated- they come with a screwdriver and are adjustable.
The "auto" trigger mode calculates the trigger level from the average of the signal shown on screen. If your timescale is too fast for the signal so that you get less than one cycle on screen, your average will change and the trigger level will jump around. Try switching to a slower timescale- or use the "normal" mode- where you manually set the level.
Yes, the sampling algorithm takes 1 cycle to recover after ranges/timescales are changed.
Hanno
Thanks! That makes sense. Odd that ch2 is fine and ch1 isn't. We'll fix this.
Hanno
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Co-author of the official Propeller Guide- available at Amazon
Developer of ViewPort, the premier visual debugger for the Propeller (read the review here, thread here), 12Blocks, the block-based programming environment (thread here)
and PropScope, the multi-function USB oscilloscope/function generator/logic analyzer
You are correct on the hardware fix, but I also thought there were some software rewites to further enhance the images. Must go back and check now.
I actually worked for the company that ground the primary mirror, (Perkin-Elmer· Norwalk, Connecticut). It was an intensive 2 year grinding process. It's a shame the company·does't get·much credit or press for one of the bigger parts of Hubble. But maybe they sqaushed all bad publicity after the problem was found.
Jim
Must go back on topic now. Sorry
Hanno said...
Getting the PropScope software right should be easier than fixing the Hubble! And unfortunately the Hubble Hardware had a problem, the mirror was ground very, very precisely- but to the wrong shape. And sadly, that couldn't be fixed in software- they had to fly "glasses" up.
Hanno
There's no poti to adjust the DC-offset. That should be done by software then. When you set to a 10* probe, the displayed value is multiplied by 10. With a 1:1 probe, the resulting 0,04V might be invisible.
Nick
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Never use force, just go for a bigger hammer!
The DIY Digital-Readout for mills, lathes etc.: YADRO
My propscope is expected tonight (while I'm out working! [noparse]:([/noparse] and Hanno is already addressing issues.
It's not that I'm happy about issues, it's that Hanno is right on top of them and my scope hasn't
even wandered up to my doorstep yet! @Hanno: does this mean I'll be installing 1.0.3 tonight? [noparse]:)[/noparse]
Common UPS guys make my night! UPS just arrived! Hmmm.. Propscope and 2010 calendar.
Edit: Had a chance to run in and take a look before dashing back off to work... Looks to be of
the high quality that I have come to expect from Parallax products. Looking forward to this!
Guys mine has not arrived yet but I have a question, I use a device with my scope a curve tracer for testing transistors and caps but you have to set the oscilloscope knobs to X and Y on the Sec/Div ,, I never thought to check if you can do this with a digital scope mine is an old analog Tektronics 2236 will I be able to do this with the prop scope thanks?
Don't worry about the Chan 1 offset right now. I'm sure Hanno will fix it, (wait it's been 2 hours, did he take a nap?)
Plenty to explore with the links you were given. I'm actually reconnecting with the scope after 15 years of not using it every day. So far so good. I miss the knobs!
Jim
Oldbitcollector said...
This is just too cool...
My propscope is expected tonight (while I'm out working! [noparse]:([/noparse] and Hanno is already addressing issues.
It's not that I'm happy about issues, it's that Hanno is right on top of them and my scope hasn't
even wandered up to my doorstep yet! @Hanno: does this mean I'll be install 1.0.3 tonight? [noparse]:)[/noparse]
Common UPS guys make my night! UPS just arrived! Hmmm.. Propscope and 2010 calendar.
Edit: Had a chance to run in and take a look before dashing back off to work... Looks to be of
the high quality that I have come to expect from Parallax products. Looking forward to this!
If your'e talking about Time/Division, yes. It's the REALLY big knob.
Jim
mikediv said...
Guys mine has not arrived yet but I have a question, I use a device with my scope a curve tracer for testing transistors and caps but you have to set the oscilloscope knobs to X and Y on the Sec/Div ,, I never thought to check if you can do this with a digital scope mine is an old analog Tektronics 2236 will I be able to do this with the prop scope thanks?
Is anyone else have a problem when setting the trigger mode to "Continuous" with the timebase at 50mSec or slower ?
Mine keeps setting the trigger mode back to "Off" ?
Bean.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1st rule of finance...Don't lose money.
Never be ashamed of making an honest·profit.
Live within your means...Make do, or do without. ·
Great discussion everyone! I'm psyched so many PropScope are in good hands- and working well.
When you set the scope to a timescale slower than 10ms/div the scope changes from sampling to streaming mode. This means you see the measurements as they happen- as opposed to the old scope where it could take up to a minute to see a screen's worth of data. Trigger's don't make sense for streaming mode, so they're disabled.
There are two trigger modes to control the trigger level, normal and auto. In normal mode, you set the level and it stays there. In auto mode, the trigger level will always be set to the average of the signal shown on screen. Auto mode works well for signals that have a slowly changing average.
Am still looking into the offset problem related to the 10x setting- also trying to get the communication protocol paper out- it's a busy season!
Hanno
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Co-author of the official Propeller Guide- available at Amazon
Developer of ViewPort, the premier visual debugger for the Propeller (read the review here, thread here), 12Blocks, the block-based programming environment (thread here)
and PropScope, the multi-function USB oscilloscope/function generator/logic analyzer
Worked late, but HAD to get the Propscope out and create some waveforms
with my demoboard. What an awesome combination!
@Hanno: When you get around to doing some basics documentation, some
spin code should fill the bill very nicely!
Question: Why did the tab that I saw for logic analyzer disappear when I
actually plugged in the Propscope? I'm getting an Oscilloscope and Analog tab.
What happened to the others?
Here's my screenshot... Just to add to the excitement. [noparse]:)[/noparse]
OBC
OBC,
When you're running the PropScope without the DAC/LSA card, you can't do logic analyzer stuff. So, when you start PropScope without the card, it'll remove those tabs. (Windows tabs can't be hidden- so I have to remove them)
Plug the card in and then start PropScope- you're tabs should stay. The firmware reads the eeprom on the card to figure out what it supports.
Hanno
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Co-author of the official Propeller Guide- available at Amazon
Developer of ViewPort, the premier visual debugger for the Propeller (read the review here, thread here), 12Blocks, the block-based programming environment (thread here)
and PropScope, the multi-function USB oscilloscope/function generator/logic analyzer
What is the reason for not enabling logic analyzer when card is not plugged in? Without the card, and with ADC channel B disable, one could have at least 10 bit logic analyzer
Hanno ·Had a thought in the middle of the night regarding the offset issue.
All Scopes I have used do not amplifiy the internal signal to make up for
the x10 probe. All that changes is the scale factor 1v/div becomes 10v/div etc.
The lowest range on my Tek goes from 20mv/div to 200mv/div, tough if you want
to measure 20mv/div with x10 probe . They sell an external low noise amp if you
want to do that. Ha
As I said first off yesterday maybe it is a pilot error.
Do you want 10 to be entered for a x10 probe in the probe management dialog or
0.1 for div by 10.
Remember when I was entering 10,100,1000 yesterday it was multipying up small
offsets and noise to full scale levels.
Multiplying to make up for the divide ratio of a x10 probe puts a real burden on the
design of the amplifier.
The help does not say any thing about this.
Also the help has a selection to get the manual and it goes to the right web page but
the link is broken, probably an IE issue like the other link.
Is there a chance that the firmware will be released at some point so that
we can modify our propscopes? (I know had it one day and ready to open it. [noparse]:)[/noparse]
Looking at the schematic it looks like it *might* be possible to accidentally
reprogram the propscope via the USB port if the your Propeller and your
Propscope were plugged in and somehow the USB settings we incorrect in
Propeller tool?
I use Windows XP under Parallels Desktop on a MacBook with the latest MacOS. The PropScope software seems to work fine. I won't have time until this weekend to give it a workout.
@OBC, I totally support the release of the PropScope firmware, but this is actually up to Hanno. He's the big cheese when it comes to firmware and software on this product. In fact, I'd like the whole product to be open-sourced - Creative Commons for the hardware and MIT for the software. We totally support the creation of alternative firmware and IDEs. NO approval needed from us (don't even ask me by e-mail - just go for it!).
We have one customer who adapted our prior USB Oscilloscope to a specific application and he plans on doing the same with the PropScope. Perhaps we'll sell him the bare PropScope boards, but he's also free to make his own if he desires.
PropScope forum? I think we can do that. Let me check with the team and see if they can swallow the idea as easily as I have.
Thanks schill for the link. I went to Adafruit and made a note that we'll update the schematic to omit the "proprietary" part. Guess we are viewed as a "closed source" company. I think we've been sharing long before it was fashionable (Stamps in Class is one example). Guess we better post the BS2 firmware pretty soon to make everybody happy [noparse]:)[/noparse]
Ken Gracey (Parallax) said...
We totally support the creation of alternative firmware and IDEs. NO approval needed from us (don't even ask me by e-mail - just go for it!).
We have one customer who adapted our prior USB Oscilloscope to a specific application and he plans on doing the same with the PropScope. Perhaps we'll sell him the bare PropScope boards, but he's also free to make his own if he desires.
I must admit I'd be interested in buying the hardware alone.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
If you always do what you always did, you always get what you always got.
Comments
I see the exact same offset (-.48V, -.49V) in the 10X mode. I'm so used reaching out and turning a knob to fix that, but alas, no knobs.
(Hardware shipped, now we will fix it in software. Worked on Hubble)
Jim
Thanks for posting about your first PropScope experience. It's very valuable to get this type of feedback!
The offset when using the 10x setting may be due to probes that need to be compensated- they come with a screwdriver and are adjustable.
The "auto" trigger mode calculates the trigger level from the average of the signal shown on screen. If your timescale is too fast for the signal so that you get less than one cycle on screen, your average will change and the trigger level will jump around. Try switching to a slower timescale- or use the "normal" mode- where you manually set the level.
Yes, the sampling algorithm takes 1 cycle to recover after ranges/timescales are changed.
Hanno
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Co-author of the official Propeller Guide- available at Amazon
Developer of ViewPort, the premier visual debugger for the Propeller (read the review here, thread here),
12Blocks, the block-based programming environment (thread here)
and PropScope, the multi-function USB oscilloscope/function generator/logic analyzer
Hanno
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Co-author of the official Propeller Guide- available at Amazon
Developer of ViewPort, the premier visual debugger for the Propeller (read the review here, thread here),
12Blocks, the block-based programming environment (thread here)
and PropScope, the multi-function USB oscilloscope/function generator/logic analyzer
I believe the variable cap in the probe is only going to do frequency compensation. It had no effect on offset.
Jim
·Probe compensation, compensates the input attenuator for AC.
Makes square waves have square shape, ie flat top not peaked or
ramped. The offset is there even if the probe ground is shorted to
the tip. Channel 2 does not exibit the offset and I am using only one
probe moving it back and forth for now.
Since 1x or 10x is just a gain factor and Channel 2 is fine maybe there
is no physical offset just Channel 1 is getting plotted in the wrong place
on the graph. I actually like that better than a hardware issue Ha.
When I get a chance I will try some other numbers 100x, 100x etc to see if
it is math based.
Tom
Hanno
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Co-author of the official Propeller Guide- available at Amazon
Developer of ViewPort, the premier visual debugger for the Propeller (read the review here, thread here),
12Blocks, the block-based programming environment (thread here)
and PropScope, the multi-function USB oscilloscope/function generator/logic analyzer
I actually worked for the company that ground the primary mirror, (Perkin-Elmer· Norwalk, Connecticut). It was an intensive 2 year grinding process. It's a shame the company·does't get·much credit or press for one of the bigger parts of Hubble. But maybe they sqaushed all bad publicity after the problem was found.
Jim
Must go back on topic now. Sorry
·Changing the value in the manage probes dialog does change the offset.
Even for Channel 2. For Channel 1 x100 put the offset almost full screen down and
x1000 blew it off the screen. Also it is an amplification as it contains noise spikes.
which appeared at x100.
For Channel 2 entering x100 produced a positive offset with small noise x100 sent it
much more positive and with larger noise as expected.
Done with input to prop scope shorted.
Tom
Nick
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Never use force, just go for a bigger hammer!
The DIY Digital-Readout for mills, lathes etc.:
YADRO
My propscope is expected tonight (while I'm out working! [noparse]:([/noparse] and Hanno is already addressing issues.
It's not that I'm happy about issues, it's that Hanno is right on top of them and my scope hasn't
even wandered up to my doorstep yet! @Hanno: does this mean I'll be installing 1.0.3 tonight? [noparse]:)[/noparse]
Common UPS guys make my night! UPS just arrived! Hmmm.. Propscope and 2010 calendar.
Edit: Had a chance to run in and take a look before dashing back off to work... Looks to be of
the high quality that I have come to expect from Parallax products. Looking forward to this!
OBC
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?
Visit the: The Propeller Pages @ Warranty Void.
Post Edited (Oldbitcollector) : 12/8/2009 10:30:05 PM GMT
Don't worry about the Chan 1 offset right now. I'm sure Hanno will fix it, (wait it's been 2 hours, did he take a nap?)
Plenty to explore with the links you were given. I'm actually reconnecting with the scope after 15 years of not using it every day. So far so good. I miss the knobs!
Jim
If your'e talking about Time/Division, yes. It's the REALLY big knob.
Jim
John Abshier
Mine keeps setting the trigger mode back to "Off" ?
Bean.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1st rule of finance...Don't lose money.
Never be ashamed of making an honest·profit.
Live within your means...Make do, or do without.
·
happen when you make a big change in the timebase.
Setting the trigger looks right and stable but it also gets
lost at times and as you say the software keeps turning it off.
To the person who asked about the probe tips. When you take off
the present spring loaded clip that is on the probe now, it just pulls
off, you attach the little one over the tip and it protects you from having
the gound part of the tip from touching something next to where you are
probing.
Tom
John Abshier
When you set the scope to a timescale slower than 10ms/div the scope changes from sampling to streaming mode. This means you see the measurements as they happen- as opposed to the old scope where it could take up to a minute to see a screen's worth of data. Trigger's don't make sense for streaming mode, so they're disabled.
There are two trigger modes to control the trigger level, normal and auto. In normal mode, you set the level and it stays there. In auto mode, the trigger level will always be set to the average of the signal shown on screen. Auto mode works well for signals that have a slowly changing average.
Am still looking into the offset problem related to the 10x setting- also trying to get the communication protocol paper out- it's a busy season!
Hanno
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Co-author of the official Propeller Guide- available at Amazon
Developer of ViewPort, the premier visual debugger for the Propeller (read the review here, thread here),
12Blocks, the block-based programming environment (thread here)
and PropScope, the multi-function USB oscilloscope/function generator/logic analyzer
with my demoboard. What an awesome combination!
@Hanno: When you get around to doing some basics documentation, some
spin code should fill the bill very nicely!
Question: Why did the tab that I saw for logic analyzer disappear when I
actually plugged in the Propscope? I'm getting an Oscilloscope and Analog tab.
What happened to the others?
Here's my screenshot... Just to add to the excitement. [noparse]:)[/noparse]
OBC
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?
Visit the: The Propeller Pages @ Warranty Void.
Having enough fun yet OBC?
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Propeller Wiki: Share the coolness!
Chat in real time with other Propellerheads on IRC #propeller @ freenode.net
Safety Tip: Life is as good as YOU think it is!
When you're running the PropScope without the DAC/LSA card, you can't do logic analyzer stuff. So, when you start PropScope without the card, it'll remove those tabs. (Windows tabs can't be hidden- so I have to remove them)
Plug the card in and then start PropScope- you're tabs should stay. The firmware reads the eeprom on the card to figure out what it supports.
Hanno
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Co-author of the official Propeller Guide- available at Amazon
Developer of ViewPort, the premier visual debugger for the Propeller (read the review here, thread here),
12Blocks, the block-based programming environment (thread here)
and PropScope, the multi-function USB oscilloscope/function generator/logic analyzer
Nick
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Never use force, just go for a bigger hammer!
The DIY Digital-Readout for mills, lathes etc.:
YADRO
·Had a thought in the middle of the night regarding the offset issue.
All Scopes I have used do not amplifiy the internal signal to make up for
the x10 probe. All that changes is the scale factor 1v/div becomes 10v/div etc.
The lowest range on my Tek goes from 20mv/div to 200mv/div, tough if you want
to measure 20mv/div with x10 probe . They sell an external low noise amp if you
want to do that. Ha
As I said first off yesterday maybe it is a pilot error.
Do you want 10 to be entered for a x10 probe in the probe management dialog or
0.1 for div by 10.
Remember when I was entering 10,100,1000 yesterday it was multipying up small
offsets and noise to full scale levels.
Multiplying to make up for the divide ratio of a x10 probe puts a real burden on the
design of the amplifier.
The help does not say any thing about this.
Also the help has a selection to get the manual and it goes to the right web page but
the link is broken, probably an IE issue like the other link.
Tom
·
Is there a chance that the firmware will be released at some point so that
we can modify our propscopes? (I know had it one day and ready to open it. [noparse]:)[/noparse]
Looking at the schematic it looks like it *might* be possible to accidentally
reprogram the propscope via the USB port if the your Propeller and your
Propscope were plugged in and somehow the USB settings we incorrect in
Propeller tool?
Propscope forum? [noparse]:)[/noparse] [noparse]:)[/noparse]
OBC
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
New to the Propeller?
Visit the: The Propeller Pages @ Warranty Void.
I use Windows XP under Parallels Desktop on a MacBook with the latest MacOS. The PropScope software seems to work fine. I won't have time until this weekend to give it a workout.
We have one customer who adapted our prior USB Oscilloscope to a specific application and he plans on doing the same with the PropScope. Perhaps we'll sell him the bare PropScope boards, but he's also free to make his own if he desires.
PropScope forum? I think we can do that. Let me check with the team and see if they can swallow the idea as easily as I have.
Ken Gracey
Parallax Inc.
http://www.adafruit.com/blog/2009/12/09/holy-smokes-parallax-is-opening-up-a-bit-cc-schematic-of-propeller-based-oscilloscope/comment-page-1/#comment-7710
Ken Gracey
Parallax Inc.
I must admit I'd be interested in buying the hardware alone.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
If you always do what you always did, you always get what you always got.