V1 and V2 not taking Y into account ?!

sylys

Hi, I just got a DS203 for Xmas and think this is a geat toy to have fun with.
However i'm having difficulties to proceed to simple voltage measurement : see attached picture, where Channel A is directly linked to "Wave Out" signal generator:
. The Y level of channel A (mark "1 >" on the graph) is set at the second horizontal gridline
. V1 is set at the top of the signal, it display "3.8v", however we can tell graphically that it is 5 1/2 gridlines above the "zero" level, so the value displayed should be roughly 2.75v.
. "Max" displays "2.84v" which confirms the above calculus
. So it looks like the DSO doesn't take into account the "Y" position of the channel to display the values of V1 (and same for V2) !


Am i missing something, or is that just a plain bug ?!


Thanks,
Sylvain.

borland

Sylvain,

Glad you like your new toy.  You may notice that there is no zero axis on the grid because the trace plots only relative values of voltage over time.

Instead of the factory's application software, you might want to try some open source software as an alternative.   I am using Wildcat 5.0 on my DS203 HW2.81 and highly recommend it.  Wildcat has been well supported by frequent updates and also provides excellent documentation.  Wildcat for DS203 is available for free on the Seeedstudio Forum (DSO Quad forum, under DSO203 GCC APP Community Edition).

sagittarius

V1 and V2 display voltage assignment is based on the low end of the zero line, not in the Channel of A vertical coordinate zero line.
(your DS203 Channel have A zero line alignment, the Channel is A no signal, the icon if signal level) Max is measured value is big because, up and down A dither signal.
The difference of V1 and V2, is the lower left corner of the △V.

sylys

borland Posted 2016-1-4 05:05
Sylvain,

Glad you like your new toy.  You may notice that there is no zero axis on the grid because ...

I find it kind of strange an oscilloscope won't show and take into account a zero axis for its display and its calculations, this looks like a basic feature one would expect from such a device. After all even a plain voltmetre will display values versus a 0v reference !

Well, i guess i'll have to live without it.

I have just installed Wildcat 5 and it indeed looks quite powerful & promising. Have to admit i'm still a bit confused about the modes & the use of buttons ! = )