<azonenberg>
Need to tweak the backoff algorithm a little bit, but i think this should work better with high latency scopes
<azonenberg>
whitequark: can you connect your rigol again?
<whitequark>
azonenberg: moment
<azonenberg>
Basically, some profiling suggested that i was spending a ton of time polling the trigger
<azonenberg>
to the point that that thread was jamming out almost everything else
<azonenberg>
especially on slow scopes
<whitequark>
azonenberg: should be up
<whitequark>
azonenberg: one thing i don't yet quite understand
<azonenberg>
?
<azonenberg>
and do you have any signal sources or triggers hooked up yet?
<whitequark>
is why the Y position of the trace affects the range that is actually being captured
<whitequark>
re signal sources, give me a moment
<azonenberg>
Because legacy oscilloscope UIs are designed to be used on a single grid where everything is one set of scales
<azonenberg>
think back to analog scope era
<whitequark>
no, i mean
<azonenberg>
to move a trace you literally feed an offset voltage into an analog addition circuit
<whitequark>
oh.
<azonenberg>
and offset the signal
<whitequark>
ohhhhh.
<azonenberg>
To make it bigger or smaller you adjust AFE gain
<whitequark>
that's actually quite interesting
<whitequark>
because it makes the range higher
<whitequark>
possible range that is
<azonenberg>
DSOs kept this same paradigm despite not being actually necessary in hardware
<azonenberg>
you still want gain and offset control
<azonenberg>
but there's no requirement that the gain and offset map 1:1 to the pixel position of the signal
<whitequark>
right
<azonenberg>
i.e. it should be possible to have a signal with huge gain that you just render small
<azonenberg>
so it's precise data, but doesnt take up much screen space
<azonenberg>
etc
<azonenberg>
In glscopeclient i'm trying to decouple these a bit, the rendered Y axis always shows the full range of the ADC
<whitequark>
azonenberg: i hooked up 1 khz source
<azonenberg>
All plots in a given viewport are equally sized regardless of the actual amplitude (i will eventually support stacking two traces in a single plot if you want an overlay for some reason)
<azonenberg>
and offset just moves the numbers on the Y axis of the plot without actually moving the rendered trace
<azonenberg>
and yes with an 8-bit scope you need this
<azonenberg>
imagine you have a DC to 5V input range for the sake of discussion
<azonenberg>
That's 19 mV per LSB
<azonenberg>
Which is not a ton of resolution for seeing weak traecs
<azonenberg>
weak signals*
<azonenberg>
meanwhile if you have DC to 500 mV range you have 1.9 mV per LSB, but then you have to attenuate strong signals
<azonenberg>
whitequark: also can you zoom in a bunch? i want a short capture, only a few hundred points, to test something
<azonenberg>
(and i havent implemented setting the timebase lol)
<azonenberg>
the 250K point captures spam wireshark pretty badly when i'm trying to do profiling
<whitequark>
azonenberg: ok sec
<whitequark>
azonenberg: 120 pts now
<azonenberg>
perfect thanks
<azonenberg>
that's 120 points total apparently
<azonenberg>
because i am seeing 30 per channel
<whitequark>
huh
<whitequark>
wait
<azonenberg>
which is totally fine for my test
<whitequark>
now it says 30
<whitequark>
azonenberg: oh
<whitequark>
it depends on the amount of selected channels
<whitequark>
it makes sense
<azonenberg>
So the memory depth is shared across all channels?
<whitequark>
i think it's just because of sample rate?
<azonenberg>
i.e. if i see 120 and i have 4 channels enabled i should actually have 30 points per channel
<whitequark>
no
<whitequark>
when i selected only ch1 it said 120
<whitequark>
when you selected all 4 channels it said 30
<azonenberg>
Then what happened?
<azonenberg>
because i am seeing 120 per channel right now in my pcaps and UI
<azonenberg>
is that what it's actually doing?
<whitequark>
that's because i just switched it back to check it out
<azonenberg>
oh, ok
<whitequark>
try again
<whitequark>
should be 30
<azonenberg>
So i'm parsing the results correctly, thats what i needed to know
<azonenberg>
yeah i am seeing 30 per now
<azonenberg>
So we're good
<azonenberg>
Have to go do something for a client but i want to get back to adding write calls to the rigol driver in a bit
<azonenberg>
can you leave the scope up for a couple hours or are you gonna have to go somewhere etc?
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<whitequark>
azonenberg: it's up for now
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<azonenberg>
bvernoux: FYI the v0.2 probe shells shipped from shapeways ETA monday to my lab
<azonenberg>
still waiting on the PCBs
<bvernoux>
ha good
<azonenberg>
oshpark's estimate when i ordered was shipping a week from today