Redpitaya Forum

I have two new 125-14 boards and calibrated one using the Auto Calibration app with a precision voltage source. When I tried calibrating the second one, the Auto Calibration fails to work.

First, I connect both inputs to ground (jumpers set to HV) and it sets the offset for both channels to -8192 and -8106 for channels 1 and 2.

Then, I connect the inputs to 5V reference. Usually, the red light turns green indicating you have connected the reference. But in this case it does not turn green but stays red.

I've used this same setup to calibrate multiple 125-14 boards and have never had this issue.

Additional info: I've tried reinstalling the OS, new SD card, tried resetting calibration to 'default' and 'factory' and that did not help. I tried the manual calibration, and I needed to set the offset to about -8240 to get 0V to read properly. Then to get 5V to read properly I needed to set the ADC gain to 1103206565. This seems quite odd...

Hello earlforeal,

Thank you for posting this on the forum.

This is highly unusual.

Which OS do you have installed on your Red Pitayas?
We have changed the way the calibration is stored in the EEPROM with 2.00 OS, but this should not impact the functionality if the calibration to "factory" settings is performed.

Please note that you can type in the exact value of the reference voltage source.
Also, please try to remove the jumpers and put them back in place to mitigate any bad jumper contact.

When did you purchase the said Red Pitaya?

I purchased these boards about 3 months ago. I am using OS 1.04 on all my boards. I reinstalled the jumpers, and tried to calibrate again with no success. Is it normal for the "Factory Reset" to set both channels to -22V?

Dear earlforeal,

We will try to solve the problem remotely first. If the issue persists, we will ask you to send an email to "support@redpitaya.com" and proceed with the RMA process.

The factory reset should set the "Manual DC" calibration page to something like this:
https://imgur.com/a/Cgqkybo

The image is of the "Manual DC calibration" screen. The offsets for the ADC code should be in the range of approximately +-200 or lower.

Otherwise, it is not normal that the "factory reset" resets both channels to -22V.

Please set the calibration of the faulty board to "factory reset" and then perform a closed-loop test with the Oscilloscope application (connect the IN1 to OUT1 and IN2 to OUT2 with coaxial cables, then send a Sine signal with 1V amplitude at a specific frequency. For example, 100 kHz). Would you be so kind as to send a picture of the result? Please make sure that the input settings are set appropriate jumper range and probe attenuation set to 1.

Are you using 1.04-28 OS? The OS version should be displayed in the bottom-right corner of the main user interface.

Please use imgur or a similar tool to send the pictures. The forum does not allow appending them.

It is OS 1.04-09. I performed the factory reset in the DC manual calibration page. However, for some reason the oscilloscope app will not open. When I try to open the app, it continues to load and refresh the page.
https://imgur.com/a/ZDsXWx2

earlforeal wrote: ↑

Thu Oct 05, 2023 2:53 pm

It is OS 1.04-09. I performed the factory reset in the DC manual calibration page. However, for some reason the oscilloscope app will not open. When I try to open the app, it continues to load and refresh the page.
https://imgur.com/a/ZDsXWx2

Try disabling any adblockers when opening the webapps.

Also, try clearing the browser cookies for the "rp-xxxxxx.local" website.

Thanks for the suggestions, but they did not work.
I've been using the 125-14 with this exact OS for 3 years now across more than 10 boards and have never had an issue that renders the board completely useless like this.

Please try to update the OS to the latest 2.00-23. If you will have issues with installation, please report them. Alternatively, I can recommend 1.04-28 ecosystem - the latest 1.04 stable OS version:
https://redpitaya.readthedocs.io/en/lat ... re-sd-card

The OS 1.04-9 was released a few years ago, so it is very hard to support and know what issues were present there.