Redpitaya Forum

Hi Red Pitaya users!

I'm using a STEMlab 125-14. I am having a problem with decimation when using the Python API on my device, comparing to the Oscilloscope feature. Specifically, the Oscilloscope seems to filter the signal, while this does not happen when I use the API. See attached plots. Here are some details:

Oscilloscope trace:

• LV setting
• 200 mV/div
• 20 us/div
• 15.625 MS/s (displayed sampling rate... 1/8th of 125 MS/s)

API trace:

• osc0 as from the "Oscilloscope Forced Trigger" Jupyter example
• osc0.decimation=8
• osc0.filter_bypass has little effect (True or False).

Even choosing decimation=64 doesn't give as clean a trace as the Oscilloscope function. Has anyone else experienced something like this? The scope has the option to select LV (less noise) or HV (more noise), but I don't see this with the API.

Any ideas would be much appreciated! Thanks

Also to point out:

setting "osc0.average = True" does not solve this.

Oscilloscope and Jupyter work on different versions of FPGA.
The results may vary.
To enable HV mode
osc0 = fpga.osc (0,20.0)

It would be nice to know the version of the ecosystem you are using.