DSO201 CA calibration opperations

Every time I turn this thing on the zero is wrong in every voltage measurement range and the scale adjustment is off as well. A Vavg measurement of a DC supply is off by a 2-10%. After many and varied attempts to resolve this I come to you all for help.

device firmware V3.26D
SW v4.22

I found a process on this forum to disable the saved waveform on boot, so I though something similar might work for the calibration. I was even able to get the default measurement to change to Vavg with a similar process.

After I follow the process below the device measures correctly, until power cycle when all the calibration info is erased or overwritten. [size=150]How do I get the calibration information to actually save?[/size]

highlight ‘ME’ using +/-
press ‘M’ to open menu
select Vavg with +/-
press ‘M’ to exit menu

short probe to itself
highlight ‘CA’ using +/-
press ‘M’ to open window
Press >|| to enter cal menu
select zero cal with +/-
adjust zero level with |<< and >>|
press ‘M’ to exit menu
hold >|| until save menu appears
press >|| to save

Connect probe to power supply and DMM (set to reasonable value for the measurement range; 3v in 1v range, etc.)
highlight ‘CA’ using +/-
press ‘M’ to open window
Press >|| to enter cal menu
select Calrange with +/-
adjust Calrange until Vavg reading matches DMM reading with |<< and >>|
press ‘M’ to exit menu
hold >|| until save menu appears
press >|| to save

I have also tried holding the >|| button until the cal window disappears and the save window appears, no difference.

Does anyone have an idea of how to save the calibration on this nano? I’ve tried everything I can find and no luck so far. My calibration is off as much as 30% and I’d rather send it back than deal with calibrating each time I need to use the thing. It’s a nice device for what it is but just too frustrating in use at this point.

Thought I’d share the “remove the F#&(^$g purple waveform” operation:

highlight ‘EX’ (purple one) using +/-
change mode to ‘off’ with |<< and >>|
hold >|| until save menu appears
press >|| to save

Also the latest versions of firmware (Ver 4.22 and 4.21) in case you bricked your DSO201 with the white screen of death.
201V4_21.zip (37.7 KB)
201V4_22.zip (37.9 KB)

This helps me and I’m sure will many others, thanks so much Jesse!


Answer anyone?

So, this happened…

While this post has been up, I have been trying to get the factory firmware to work at some acceptable level because I bought a DSO210 with the LCD9341 screen. Installing the old benf firmware would cause a white screen of death. A couple months later and user rimidalv007 made a new benf build that includes my device. HOORAY!!!

I’ve posted a copy so its easier to find on the forum.

The original:
DSO201_BenF_3.64_APP_and_3.53_LIB.zip (53.5 KB)

It is better to just post the link and not attach another copy. If the original post is updated, you might fail to update yours, and some people will keep downloading your old version instead…