Re: missed keystrokes problem, back with a vengeance.
On Sun, 2017-01-29 at 08:47 -0500, Gene Heskett wrote:
> Greetings everybody;
>
> I am in the process of bringing a nearly 70 yo Sheldon lathe back to
> life, useing an raspberry-pi 3b for the machine controller.
>
> However, I have now had 5 different keyboards plugged into it, some
> wired, some wireless, and none of them can give me a dependable response
> to a key, and the error seems much worse for the key-up event. When
> driving the machine by hand as we often do for one-offs, missing a keyup
> event can be disastrous for the part being made because it keeps on
> cutting until you've given that, or another key, a quick tap to stop the
> unwanted motion.
I'm wondering if the problem is noise on the power, or RFI noise being
picked up/interfering with the usb cable and/or PI in general. I'm
guessing that the lathe is probably kicking out a shed load of RF noise
into the air or on to the power line and the pi is not overly hardened
for such a harsh environment.
Another possibility is that they keyboard/pi is working ok, but the
pi>lathe is where the problem is. The only way to tell would be to some
how have the application give a visual indication of the keys pressed
state so you would know if the pi had even seen the key released event.
>
> There is something funkity in the usb keyboard handling that can get much
> worse with a reboot, or get almost perfect with a reboot.
>
> Its all uptodate a/o yesterday. The psu is a 4 amp box, making 5.07 volts
> solidly. Verified with a 100 Mhz scope.
>
> What can I do to fix this?
>
> Cheers, Gene Heskett
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