Downsampling

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IonutGorgos
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Joined: Tue Jun 14, 2016 2:10 pm

Downsampling

Post by IonutGorgos »

16 number of values). Sample interval is 3.2 ns and the no. of samples captured is 625.

When I import in Matlab the signal look like this
10 bits - picoscope_matlab.png
which is fine.

Now the problem is when I'm using the API functions from DLL with Python.
I set the observation duration ( 2 µs in my case) , the sampling interval at 3.2 ns , channels, trigger. Then I'm calling the RunBlock() function and retrieve the values with downSampleMode = 2 (Average) and downSampleRatio = 16 (2.0 bits resolution enhancement) and then save them in .mat file. Now my no. of samples is 39, not 625. Here is the photo
10 bits - python_matlab_fig.png
I tried to increase the observation duration (16*2 µs) , but my plot is looking different :
10 bits_python_no_samples.png
I don't know what to do. Please help me. Thanks in advance.

Ionut
-->
Hello,

I have a PicoScope 6404D, and currently I'm developing a script written in Python using PicoPython from this source:
https://github.com/colinoflynn/pico-python

My problem is with the downsampling. I will attach some photos to explain.
In this photo
10 bits - picoscope 6.png
I have the signal on the channel A with the 10.0 bits resolution ( 2.0 bits --> 16 number of values). Sample interval is 3.2 ns and the no. of samples captured is 625.

When I import in Matlab the signal look like this
10 bits - picoscope_matlab.png
which is fine.

Now the problem is when I'm using the API functions from DLL with Python.
I set the observation duration ( 2 µs in my case) , the sampling interval at 3.2 ns , channels, trigger. Then I'm calling the RunBlock() function and retrieve the values with downSampleMode = 2 (Average) and downSampleRatio = 16 (2.0 bits resolution enhancement) and then save them in .mat file. Now my no. of samples is 39, not 625. Here is the photo
10 bits - python_matlab_fig.png
I tried to increase the observation duration (16*2 µs) , but my plot is looking different :
10 bits_python_no_samples.png
I don't know what to do. Please help me. Thanks in advance.

Ionut