I apologize but I do not understand the language (I use google translator). So it is normal to see 0.2 to 0.3 volts in the absence of signal with the probe grounded?
I very much doubt that this is a limitation, my friend’s DSO nano v2 measures exactly 0V when the probe is grounded. According to him he has never calibrated it.
Thanks for the reply, I did the calibration several times, successfully, saving the parameters, I’m writing a manual in Italian (14 A4 pages!) of this oscilloscope and I can say to use it well.
The lowest flow rates (and not on the 10V/div) do not give 0.00V with the probe grounded. However, I still repeat the calibration.
Tnx
PS: The official manual v.0.92b explains that the internal generator can provide a square wave with adjustable duty cycle, but I do not find it anywhere this duty cycle regulation.
goliath11, did you already found a solution for this calibration problem?
I think I found! I updated my quad few times with older versions and nothing helps until I updated wit APP v2.51 and voila! Accurasy is around 5% (10V/div: vrms = 0, vdc = 0, vmin = 0, vmax = 400mV) which can be accepted for my applications.
Please, let us know if you manage to update and discard the problem.
I tried that package (standard procedure, POWERON+KEY1, copy chipSYS_B151.hex, wait .rdy, restart, copy chipAPP_B253.hex, wait .rdy, restart), but i cannot see any upgrade (i.e.: no XY mode and still the slow refresh with timescale >1ms); at startup i see “SYS chip V1.51” and “APP Ver 2.50” (i expected 2.53).
I just tried to upgrade my DSO quad with the contents of the latest pack.rar (SYS_B151.hex, APP_B253.hex), but it seems something went wrong
Powering on the device, I only see an all-white screen no beep, there it hangs.
My Linux’s USB stack fails to (completely) recognize the device, too:
[2476525.688058] usb 1-2: new full speed USB device using uhci_hcd and address 58
[2476525.812033] usb 1-2: device descriptor read/64, error -71
[2476526.040029] usb 1-2: device descriptor read/64, error -71
[2476526.256025] usb 1-2: new full speed USB device using uhci_hcd and address 59
[2476526.380046] usb 1-2: device descriptor read/64, error -71
[2476526.609042] usb 1-2: device descriptor read/64, error -71
[2476526.824542] usb 1-2: new full speed USB device using uhci_hcd and address 60
[2476527.232018] usb 1-2: device not accepting address 60, error -71
[2476527.344030] usb 1-2: new full speed USB device using uhci_hcd and address 61
[2476527.752018] usb 1-2: device not accepting address 61, error -71
[2476527.752042] hub 1-0:1.0: unable to enumerate USB device on port 2
That is, it seems I cannot downgrade/upgrade to any useable state? Starting at this point, what are fall-back strategies to install the firmware? Directly write them to the flash chip? It would be really nice to un-brick this little guy. I only owned it for some days, but it really prooved to be a helpful tool…
(EDIT) The “Device Firmware Upgrade V3.10” still seems to work. In the meantime, I also tried to copy the firmware using the mtools suite, but didn’t have success with it. (Still the same white screen when switching it on without pressing the start/pause button.) Hopefully, somebody has a good hint for me. (And once I actually understand what went wrong, I’ll update the wiki’s Quad firmware update page.)
(EDIT #2) I again uploaded sys-1.50 and app-2.51 (from the GIT repo) to the device using mtools. The initial screen displaying all the version numbers is somewhat garbled (will take a picture of it after having had some sleep), but the application at least seems to start. But due to the garbled initial screen, I guess parts of it are possibly still overwritten. When starting up normally (without pressing the run/pause button), the USB disk emulation still doesn’t work (as printed above.)