Calibration

Just about everything about Red Pitaya
Post Reply
cydrollinger
Posts: 5
Joined: Thu May 12, 2016 8:07 pm

Calibration

Post by cydrollinger » Sat Jan 28, 2017 1:24 am

I have read some of the many posts on calibration via command line, oscilloscope and signal generator app, and oscilloscope pro app. I have not found on my Red Pitaya, which was calibrated - Oscilloscope&Signal Generator=> naksd9biz2 and Spectrum analyzer=>xa3nvzhecn, does not give accurate readings, if I calibrate to defaults, or if I run through the calibration instructions for LV and HV. My Red Pitaya has been updated to the OS 0.98-86 and I suspect the purchased calibration is wiped.
Question: Does Oscilloscope & Function Generator App have the capability to calibrate, I have not found a way, a button, a process, a sequence, and abbra kadabbra did not work?
Question: I have not found going through the Oscilloscope Pro App has not been able to give accurate results. When applying the known 1.000V supply to both the in1 and in2 on the LV settings results in a .9V reading. Is there a something behind the scenes I do not get, there is a radio button listing .9V while the instructions state that the refenece voltage is 1V!? So, it is curious that I set the inputs 1 &2 to 1.000V but once complete the readings are .9V which is the radio buttons value. If I change the radio button to 1.000V it reverts back to .9V. What going on?

Nils Roos
Posts: 1441
Joined: Sat Jun 07, 2014 12:49 pm
Location: Königswinter

Re: Calibration

Post by Nils Roos » Sat Jan 28, 2017 2:30 pm

Question: Does Oscilloscope & Function Generator App have the capability to calibrate
No, they can read and apply the calibration values, but they have no option to change them.
Question: I have not found going through the Oscilloscope Pro App has not been able to give accurate results. [...] What going on?
I do not know anything about the internal working of the PRO apps, because I do not have access to their source code. Only support@redpitaya.com can answer questions about the PRO apps.

cydrollinger
Posts: 5
Joined: Thu May 12, 2016 8:07 pm

Re: Calibration

Post by cydrollinger » Sat Jan 28, 2017 5:57 pm

Okay, moving on. I could calibrate from the command line of Red Pitaya through Putty. I have a question about the command line as I am so limited in the things I can do, permission denied. When I SSH into Red Pitaya through Putty I get a command line that looks like root@rp-0f1eaa:~# instead of the expected repitaya> as I see in any tutorial. I have access to the file system of Red Pitaya, but have not been able to run calibrate, a utility tool I have got from git hub and placed into the temp folder. I copy the file, calibrate, into temp through winscp. Once I navigate into the tmp folder and I can see the file I placed there but it will not allow me to run calibrate, permission denied. I have read some of the posts on this forum and did see a comment on running the command "rw", read/write permission I suspect.
Question: if I see the command line root@rp-0f1eaa:~# instead of the expected repitaya> do I have access to Red Pitaya in a Shell to perform calibration?
Question: If I am shelled in and don't have access to run the example script for calibrate as given in the example on git hub what next?

Nils Roos
Posts: 1441
Joined: Sat Jun 07, 2014 12:49 pm
Location: Königswinter

Re: Calibration

Post by Nils Roos » Sat Jan 28, 2017 9:18 pm

I get a command line that looks like root@rp-0f1eaa:~# instead of the expected repitaya> as I see in any tutorial.
I suppose you mean tutorials from the wiki? Have you seen this notice? Most of the content in the wiki pertains to old versions of the Red Pitaya OS and ecosystem. Some things are still valid in principle, but look a little bit different. For example, in current releases the expected commandline prompt is what you are seeing.
I copy the file, calibrate, into temp through winscp. Once I navigate into the tmp folder and I can see the file I placed there but it will not allow me to run calibrate, permission denied.
In order to execute any file you copy from a windows system onto the Red Pitaya, you need to set execute permissions after copying. In the PuTTY shell, write

Code: Select all

chmod 777 /tmp/calibrate
I have read some of the posts on this forum and did see a comment on running the command "rw", read/write permission I suspect.
You only need to do that if you want to write something to a path starting with /opt/redpitaya .

cydrollinger
Posts: 5
Joined: Thu May 12, 2016 8:07 pm

Re: Calibration

Post by cydrollinger » Mon Jan 30, 2017 5:18 pm

Thank you! I will give these suggestions a go and let you know how they worked. When you say old do you mean hardware or OS.?

cydrollinger
Posts: 5
Joined: Thu May 12, 2016 8:07 pm

Re: Calibration

Post by cydrollinger » Mon Jan 30, 2017 7:17 pm

So, to recap, I have added the utilty, https://github.com/edgo914/RedPitaya/tr ... /calibrate, written by Edgo914 at Github. I downloaded the utility and copied it into RP through winSCP. I putty into the RP and write chmod 777/tmp/calibrate, issue the command ./calibrate, and the response is -bash: calibrate: command not found
The file was copied into directory /tmp and can be located with putty. Either the github file is not a utility file I can run from putty in RedPitaya, not executable, or?

Thank you!

Nils Roos
Posts: 1441
Joined: Sat Jun 07, 2014 12:49 pm
Location: Königswinter

Re: Calibration

Post by Nils Roos » Mon Jan 30, 2017 9:38 pm

When you say old do you mean hardware or OS.?
The OS. Everything in the wiki was written for ecosystem releases v0.92 / v0.93 .
the response is -bash: calibrate: command not found
With OS release v0.94, the underlying architecture of the OS was changed from a software emulation for floating point calculations to hardware-based floating point support. The effects of this were
a) some performance improvements,
b) incompatibility with all software that was build for the old architecture.
The symptom is always a "not found" error when you try to execute unsuitable binaries.

The best way to get edgo's tools to run is to compile them from source on the Red Pitaya.

cydrollinger
Posts: 5
Joined: Thu May 12, 2016 8:07 pm

Re: Calibration

Post by cydrollinger » Tue Jan 31, 2017 12:39 pm

NIls,

Thank you for your help! Ok, I have a better understanding. Is there another open source tool that might work better for the current 0.96-86 OS? I would have a look at something newer, or maybe, develop something new. Do you have another suggestion on getting RP calibrated to read correct amplitudes? But, may still go back and make Edgo's stuff on RP.

Cy

Nils Roos
Posts: 1441
Joined: Sat Jun 07, 2014 12:49 pm
Location: Königswinter

Re: Calibration

Post by Nils Roos » Wed Feb 01, 2017 9:46 pm

There is also the calib utility pre-installed on the Red Pitaya, instructions how to use it are here.

bhaskarm
Posts: 6
Joined: Sat Jul 16, 2016 6:48 pm

Re: Calibration

Post by bhaskarm » Fri Feb 10, 2017 7:33 pm

Hello Cy,
I have been trying to calibrate my Red Pitaya using the Scope Pro; I am using the latest stable OS image. The ScopePro can do the calibration if you click on the "SETTINGS" link on the top right corner. It will bring up a menu that has Calibration capabilities. You can reset the calibration to defaults or go through the calibration routine for the LV, HV and DAC outputs. You can end the calibration at any intermediate step by clicking the "DONE" button, for example if you only want to calibrate the LV input and do not care about the HV and DAC.
It seems to work well for the offsets and to a lesser extent on the gain. You do not have to use any command line utilities if you do not want to.

Post Reply
jadalnie klasyczne ekskluzywne meble wypoczynkowe do salonu ekskluzywne meble tapicerowane ekskluzywne meble do sypialni ekskluzywne meble włoskie

Who is online

Users browsing this forum: Google [Bot] and 29 guests