alex123go / redpitaya_acquisition Goto Github PK

Hi! First of all - very nice down!
That is what I was looking for!
Just a short question, can on-trigger acquisition (to get signal synchronized with the reference signal) be implemented somehow easily?

Best,
Ivan

Hi Alex,

First of all, thank you a lot for releasing the new version, I have had my hands on it just now - it is very cool and easy to use (I use a non-GUI version).
Decimation works perfectly (I know it is with no averaging).
However, I noticed that the on-trigger acquisition behaves weird.

To explain the issue, here is how my signal looks like (trigger signal is in blue, I connected it to the 2nd channel just to record them synchronously):

The signal period is 0.1 s.
These rectangular pulses (0..3.3V) I use for on-trigger acquisition for the 1st channel (orange signal is of my interest for stable acquisition).

Further, the reference signal connected to the EXT_TRIG pin, I run your script (non-GUI),

for bUseTrig = 0 I clearly see that on-trigger ACQ is OFF (as the recorded signals are randomly places in the time domain):

when bUseTrig = 1 on trigger ACQ is ON and it can be seen, but something like 50% of the signal is being shifted (and sometimes there are small shifts as well). Here I recorded 10 cycles with bUseTrig = 1 , in this case, 5 cycles overlap well and 5 do overlap but with some shift relative to the first 5 (also they are quite unstable in phase actually).

Do you have an idea from where this problem could come from?
I have tried to play with some parameters but did not succeed. Also, I tried to feed ideal signals to the RP generated using a function generator, the results are the same. I also played with the phase for the signal, but it did change nothing.