Redpitaya Forum

Hi,

Quick question upon measuring a voltage (simple circuit with two 100k resistors in serial and 5v from red pitaya in), with a multimeter i measure aprox 2,34 volts now with with the scope application it shows 2.041v?

Am I missing something here or maybe the red pitaya needs calibration?

Any help, info or tips appreciated.

regards,
Leo

No one any ideas ? ..

regards,
Leo

If you measure an unexpected voltage from a known source, you should certainly try to calibrate your Red Pitaya (see here).

Hi Niels,

Well actually its not an unknown voltage its the first example from the elektor book about red pitaya soms know the voltage and als have measured with a multimeter. Just suprised me the pitaya measurement was about 0,35v apart from what the multimeter tells me.

Anyway thanks for your reply and i will give calibration a go.

Regards,
Leo

Niels,

So in the attachment picture is what I see if in the oscilloscope application i connect out1 to in1. The generator is set to 1v amplitude but still I see in the scope the amplitude on IN1 is .845v?
Pretty new to electronics and red pitaya, coming from a software background and a recent HAM operator so i might be totally doing the wrong thing or looking at it the wrong way though?

Thanks,
Leo

First try to reset the calibration settings to factory defaults - there's a menu item in the scope app for that. When I did that with a totally miscalibrated RP, it brought the measured input from 1.13V to 0.999V for a 1V DC generated output.

Hi Niels,

Just did the factory defaults for the calibration in the scop... now the measured voltage is even lower, 766mV.. Weirdnes all around not sure what else to try but suggestions welcome.

thanks and greetings,

Leo

And what happens when you do the calibration procedure?

Hi Nils,

I have shorted IN1 and IN2 and pressed calibrate. I have IN1 to 1v and IN2 to 20v btw not sure if that makes a difference. Previously it was and still is after calibration still hovering around 827mV.

regards and many thanks for your assistance.

Leo

Just to anwser the solution to my own problem

Did a two step calibration through the oscilloscope app:
1. standard calibration with IN1 and IN2 shorted
2. LV/HV calibration with a known stable input voltage

Problem gone and Red Pitaya now nicely calibrated !

regards,
Leo