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Grogster

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Joined: 31/12/2012
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Posted: 06:14pm 30 Aug 2014

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So, is it the Parallax keyboard that WON'T work with the MM?

Smoke makes things work. When the smoke gets out, it stops!

hitsware
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Joined: 23/11/2012
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Posts: 535

Posted: 06:20pm 30 Aug 2014

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Precisamundo !
AFAIK just in that 1 specific area ..

robert.rozee
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Posted: 06:38pm 30 Aug 2014

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has anyone tried to diagnose the root cause? perhaps the keyboard controller creating current spikes on the supply line that are getting back into the maximite, noise getting into the PIC over the data lines, invalid data values being returned (or spurious data being produced). are pins 80 and 84 on the MX695 5v tolerant?

if a list of possibilities could be created, then various people could check them out.

rob :-)

hitsware
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Posted: 02:46am 31 Aug 2014

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Robert,

from spec sheet :
"
Note: This keyboard is designed for use with the Parallax Propeller Chip and is not guaranteed to function with any other systems, including PCs.
"

robert.rozee
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Posted: 04:45am 31 Aug 2014

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oops, no, i didn't mean just the parallax keyboard, i was thinking of the wider problems that folks have reported with keyboards from a number of sources.

my understanding is that there are some percentage of PS2 keyboards that cause problems with the maximite, these keyboards coming from many different suppliers.

rob :-)Edited by robert.rozee 2014-09-01

hitsware
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Posted: 06:22am 31 Aug 2014

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> wider problems

I wasn't aware of that. Could be the same thing then (or not)

Grogster

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Posts: 9501

Posted: 12:54pm 31 Aug 2014

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Yes, I had(and still have, to some extent) that issue with KB's on the CMM. The KB handler seems to get confused. Type 'P', you get a 'Q' or nothing at all with a total KB lockup, then KB refuses to respond at all. Removing the KB and plugging it back in with the CMM still powered does not fix the problem(KB lockup not the problem, CMM KB handler lock-up seems to be the problem), and you have to reboot the CMM.

This seems to be happening less with me since I moved to using linear regulators and transformer-based PSU's for the CMM(with plenty of decoupling caps), but it is as very odd one - even Geoff said he had no real idea WHY this should be happening.

I should also point out, that only a few of us have that issue. To the best of my knowledge, 99% of users have no issues with the KB - which makes it really hard to track down WHY this should be singling me out....

Smoke makes things work. When the smoke gets out, it stops!

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