Raghunathan

Open Logger : Function Gen issue ..

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I was trying to generate a Sine and Square wave using the FG functionality in the Open Logger.  A few observations :

1. I chose a Sinewave of 1V pk-pk and 50Hz to simulate a mains frequency sampling.  I then fed this signal to AIN1 channel. But was surprised to see that the pk-pk was far less than 1V. It actually was around 0.6V. Tried other voltages also but the result was same. Not sure why. 

2. I then tried a low frequency square wave and what i got was not anywhere near a square wave -- it had pretty rounded rise and fall edges. 

Is the above due to the fact that this board does not use a DAC but only a resistor network instead ? Or I am missing some setting ??

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Hi @Raghunathan,

Could you attach a picture of your settings? I was unable to replicate the situation regarding the peak to peak voltage (my screenshot is using 50 Hz, but 60 Hz did the same as well).

With regards to the square wave appearing curved, I was only able to see this when I zoomed in so that the time base was at 2 uS/division or less but at that point you are just viewing the output settling time of the requested change which should be about 580 nS as noted on slide 91 on the detailed Microchip Masters Presentation.

Thanks,
JColvin

1V p2p view.png

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Thanks Colvin !

After I posted and shut down the system and re-started all things fell in place.  Possibly in the first instance I was changing too many parameters on the fly with both Streaming and WavGen running and the system became unstable. 

Now its fine.

I would like to make make all my settings on the right side as Default settings to be pulled up when the WaveForms live loads .. I think Profiles are stored in flash. Will selecting Log on Booting do that  ? 

Also I get a "Error Starting or Running " if I try to log to a SD Card. Its a Sandisk 32GB MicroSD formatted for FAT32.  The filename is there but filled with gibberish. 

Edited by Raghunathan

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