Thanks for the heads up!
The IRQ handler should not be that slow. The usb routines may temporarily disable interrupts though – can’t remember at the moment. Anyway if it drops events constantly but timer is accurate (which I’m also not sure about. need testing!), we can use a binning buffer to record the events and smooth them out with a filter.
Looking forward to a proper trackball discussion thread 
@guu ah yes, I’ll definitely try that out. Thanks!
hi
I am sorry if I am committing necromancy on a 1.5 year old thread but it seems very awesome and I can’t figure out why I cant get the firmware to work.
when I execute the script the keyboard becomes unresponsive and the LED on the underside is flashing.
Re-plugging makes it work but there is no difference to before, the firmware stayed the same.
here is the output from the Script:
Verifying archive integrity... MD5 checksums are OK. All good.
Uncompressing DevTerm Keyboard Firmware
Do you wish to flash the devterm keyboard firmware at your own risk?(y|n)y
dfu-util 0.9
Copyright 2005-2009 Weston Schmidt, Harald Welte and OpenMoko Inc.
Copyright 2010-2016 Tormod Volden and Stefan Schmidt
This program is Free Software and has ABSOLUTELY NO WARRANTY
Please report bugs to http://sourceforge.net/p/dfu-util/tickets/
dfu-util: Invalid DFU suffix signature
dfu-util: A valid DFU suffix will be required in a future dfu-util release!!!
dfu-util: Cannot open DFU device 1eaf:0003
dfu-util: No DFU capable USB device available
Waiting for /dev/ttyACM0 serial...Done
What can I do?
Thank you
oh no, I was not paying attention and flash this DevTerm keyboard firmware to my new UConsole, and the keyboard and mouse is of cause acting up now. I tried flashing back the UConsole firmware but got this error, anybody can help?
Plug in an external keyboard, run lsusb and see what comes up.
what is the output if you run
sudo ./flash.sh
the output is in my screenshot, something with “Invalid DFU suffix signature” and “No DFU capable USB device available”
Ok, fat chance you’re gonna get it back without big problem – it still recognizes itself as a “DevTerm”.
Some versions of the DT keyboard firmware will refuse to be flashed once it’s “brought online” – that means, you have ~1 sec on usb plugging in to initiate the flashing process.
First thing to try: completely power it off and back on again. It’s possible to bring it back into flash-happy mode.
If it still doesn’t work, remove the front plate, take it out to a PC and flash it there (within 1sec!). Let us know how it goes, and don’t worry, we’ve got plan B/C/D to say the least.
Thanks for reply, wow I didn’t know the keyboard had it’s own micro usb port for firmware updates. I tried it on another raspberry pi with the keyboard plugged in externally, changed the usb’s address in the flash.sh (from uconsoles github) to match what i found when running lsusb, but it gave me the same errors as in my first post, so no progress. “Failed to open serial device” and “Invalid DFU suffix signature”
Any other ideas? 
Help Needed,i install V5,but how can i switch around different modes?I press FN key and Left or Right arrow in the DPAD,but nothing happened,neither the notification apperened.