help needed for waveform

Discuss x0x construction and related issues

Moderators: altitude, adafruit_support_bill, adafruit, phono, hamburgers

Please be positive and constructive with your questions and comments.
Locked
yom
 
Posts: 2
Joined: Thu Apr 03, 2014 6:26 pm

help needed for waveform

Post by yom »

Hi,
I've just built the VCO and I have problems with waveforms (especially square)
Details:
Willzyx kit
Measures made with a soundcard scope probe + software
I've already try to change ground: no change
All measures with mulimeter are good
Saw wave is a little more beautiful but the amplitude of peak is not precise and the square is...submarine
Ideas?

Image
Image

Agent_24
 
Posts: 87
Joined: Thu Feb 23, 2012 6:08 pm

Re: help needed for waveform

Post by Agent_24 »

I would say it would help to post photos of your board (front and back)

Do the usual checks, make sure everything is soldered correctly, around the right way, in the right places.

User avatar
antto
 
Posts: 1636
Joined: Thu Apr 15, 2010 3:21 pm

Re: help needed for waveform

Post by antto »

the soundcard scope cannot measure levels accurately, so ignore it
also, the waveforms themselves will look weird (like yours) because most soundcards are AC-coupled

so.. they both look okay to me

yom
 
Posts: 2
Joined: Thu Apr 03, 2014 6:26 pm

Re: help needed for waveform

Post by yom »

nothing decent device to take photos...
but I took time to build it and for the measures.
I work on an old laptop with integrated sound card also
Many parasite or interference on waveforms...
Maybe i'll adjust the VCO at the end for more precision following your method antto

Locked
Please be positive and constructive with your questions and comments.

Return to “Making x0x”