Feature requests

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Jasper

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Aug 7, 2012, 1:33:23 PM8/7/12
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Hi,

I've just received my CEE. It appears all is working well! Took me a while to figure out that I can horizontally zoom with a double click. How do I zoom vertically? Anyway I wanted to ask about the following features which I hoped would be available:

- Duty cycle setting for the square wave
- Ability to save / export measured data
- Ability to zoom on the xy-plots

Finally I was wondering what the speed of the current regulation is, when sourcing current with a square wave for example. 

Thanks for your time.

Best regards,

Jasper

Ian Daniher

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Aug 15, 2012, 12:22:25 AM8/15/12
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Hi Jasper,

Thanks for writing! Sorry for the delay in my response, it's been a busy week!

Vertical zooming is currently supported through the xmega's programmable gain amplifier - a 1x to 64x hardware gain that happens before the analog to digital conversion takes place. This feature is exposed in a dropdown box in the pane on the right side of Pixelpulse for both voltage channels. Note that each increase in gain results in a corresponding decrease in range. Additionally, use of this hardware gain will zoom the x-y plot.

Thanks for the suggestions for the additional Pixelpulse features! At the moment, all of those features are supported exclusively through the API, documented at wiki.nonolithlabs.com/cee/Simple_REST_API_V1/, with a convenient implementation in Python at github.com/nonolith/connectClientPython

Kevin, the better looking half of Nonolith, is hard at work on a nontrivial overhaul of Pixelpulse which will bring data export, advanced waveform setting functionality, and more to a Chrome tab near you, within the next week or two.

As for setting current - the exact settling time of our current control loop depends upon the impedance of the attached load and as such gives an effective maximum frequency of anywhere from 100Hz to 10KHz. What's your expected use case? 

Best!
--
Ian Daniher

Jasper

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Aug 20, 2012, 1:33:41 PM8/20/12
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Hi Ian,

Thanks for the reply. At the moment I'm mostly interested in PWM-ing LEDs. As such the hardware zoom doesn't really work as I'm mostly interested in the current... Also the duty cycle would be nice to have but I'm not really in a hurry so I'll save myself some programming and wait for the GUI.

Also for the LEDs I would like to use the current control with the PWM. But it appears that with a square wave, from 100 Hz onwards the response starts to degrade... 1 kHz appears to fast. With voltage sourcing it works but then I have to add a resistor from which I then have to calculate the effect. Also not a huge problem, but I like things to be convenient ;-)

Best regards,

Jasper
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