Keyboard debouncing

If you're having problems with the hardware of a DM42, post about them here.
kevinvinv
Posts: 11
Joined: Wed Jul 11, 2018 10:40 pm

Re: Keyboard debouncing

Post by kevinvinv » Fri Nov 02, 2018 3:47 pm

So getting back to the topic :)

Does anyone think there is anything we can do to fix the keyboard bouncing problem? I am thinking it can be addressed in software and I am trying to figure out if anyone else thinks it is worth working on.... of if I am the only one that is plagued by it :)

User avatar
ijabbott
Posts: 109
Joined: Fri Dec 15, 2017 1:34 pm
Location: Manchester, UK

Re: Keyboard debouncing

Post by ijabbott » Fri Nov 02, 2018 9:41 pm

kevinvinv wrote:
Fri Nov 02, 2018 3:47 pm
So getting back to the topic :)

Does anyone think there is anything we can do to fix the keyboard bouncing problem? I am thinking it can be addressed in software and I am trying to figure out if anyone else thinks it is worth working on.... of if I am the only one that is plagued by it :)
The software would be the closed source DMCP, so the only people who can work on it are SwissMicros themselves.

MikeD
Posts: 3
Joined: Sun Jul 22, 2018 9:05 am

Re: Keyboard debouncing

Post by MikeD » Fri Nov 02, 2018 10:24 pm

I have the same problem, every now and then, I hit the #3 key and it doubles. It is very rare so I don't worry to much about it. I did turn off the fast auto-repeat.

Dave Britten
Posts: 46
Joined: Wed Jun 14, 2017 7:27 pm

Re: Keyboard debouncing

Post by Dave Britten » Mon Nov 05, 2018 2:23 pm

My big fear is that I'm going to hit Shift-Clear, CLP or CLV, and get a bounce on that function key, nuking something I didn't want to delete. Hasn't happened so far...

User avatar
Walter
Posts: 793
Joined: Tue May 02, 2017 9:13 am
Location: Close to FRA, Germany

Re: Keyboard debouncing

Post by Walter » Mon Nov 05, 2018 3:15 pm

Dave Britten wrote:
Mon Nov 05, 2018 2:23 pm
My big fear is that I'm going to hit Shift-Clear, CLP or CLV, and get a bounce on that function key, nuking something I didn't want to delete. Hasn't happened so far...
Golden rule of layouting: avoid such possibilities!
DM42 SN: 00041 --- Follower of Platon.

HP-35, HP-45, ..., HP-50, WP 34S, WP 31S, DM16L

Dave Britten
Posts: 46
Joined: Wed Jun 14, 2017 7:27 pm

Re: Keyboard debouncing

Post by Dave Britten » Mon Nov 05, 2018 4:39 pm

Walter wrote:
Mon Nov 05, 2018 3:15 pm
Dave Britten wrote:
Mon Nov 05, 2018 2:23 pm
My big fear is that I'm going to hit Shift-Clear, CLP or CLV, and get a bounce on that function key, nuking something I didn't want to delete. Hasn't happened so far...
Golden rule of layouting: avoid such possibilities!
Agreed, but the multi-purpose soft menu keys limit that somewhat. The 17BII, 19BII, and 27S do something clever for deleting stat/cash flow lists: you first press Shift-Input (Clear Data), then it prompts you "Clear list?", with "Yes" on menu key 1, and "No" on menu key 6. If you choose to clear the list, it then prompts you "Also clear list name?", i.e. totally delete the list rather than just removing the data. But for the second prompt, it moves "Yes" to menu key 2, so an unintentional second press of menu key 1 doesn't result in deleting more than you intended.

Since the CLV and CLP functions are themselves part of the soft menus, Free42 would have to do something like not putting any variable/program names on the same menu item as CLV or CLP, at least for the first page of variables/programs. I would certainly welcome such a change.

kevinvinv
Posts: 11
Joined: Wed Jul 11, 2018 10:40 pm

Re: Keyboard debouncing

Post by kevinvinv » Mon Nov 05, 2018 5:35 pm

Well I will say this... I just did the procedure to loosen up the keys... WOW what a difference... Maybe that will help with my bounce problems.

I did not know the keyboard code was closed source. OK. At least I know there is nothing I can do about it :) :(

c785
Posts: 83
Joined: Mon Apr 24, 2017 9:22 pm

Re: Keyboard debouncing

Post by c785 » Tue Nov 06, 2018 8:39 am

MikeD wrote:
Fri Nov 02, 2018 10:24 pm
I have the same problem, every now and then, I hit the #3 key and it doubles. It is very rare so I don't worry to much about it. I did turn off the fast auto-repeat.
The 3 key is the culprit most of the time on my calculator as well, but I've seen it happen with ENTER as well. Whether I enable fast autorepeat or not, I haven't been able to tell the difference so far.

When bouncing occurs, it's so quick that I think it should be physically impossible to press the key twice in such a short time. The point of debouncing logic is that the device rejects multiple presses that occur too quickly to be physically plausible, and I think the code we have on the DM42 now is too permissive. For a calculator of such overall quality (and this sort of price), I'd really expect the manufacturer to fix this issue. Or release the code so we can do it ourselves. Why hasn't this been addressed already?
DM42 #84

Augusto.Berg
Posts: 3
Joined: Sun Oct 21, 2018 12:05 pm

Re: Keyboard debouncing

Post by Augusto.Berg » Tue Nov 06, 2018 10:05 am

I bought one that is on the way and now I'm really worried about this "bug" :shock:

Waiting for news... :|

rprosperi
Posts: 375
Joined: Mon Apr 24, 2017 5:48 pm
Location: New York

Re: Keyboard debouncing

Post by rprosperi » Tue Nov 06, 2018 2:18 pm

c785 wrote:
Tue Nov 06, 2018 8:39 am
For a calculator of such overall quality (and this sort of price), I'd really expect the manufacturer to fix this issue. Or release the code so we can do it ourselves. Why hasn't this been addressed already?
This problem appears to be present in only a very small number of units, seems like less than 1% of units sold, and among those, some report the problem went away and others that Logan's 'keyboard softening' technique eliminated the problem as well, so the 'fix' is likely not a design or manufacturing change, possibly just a bad part or poor assembly alignment in a couple units. SM/Michael has been very responsive with customers that have contacted him directly for support, and/or possibly replacement, if required to correct the problem. I understand your desire to share your experience here, but it is likely more productive for you to contact them for help directly (e.g. email Michael) than to post suggestions here of what they could/should do, which can also raise undo concern with other buyers, as you see just above my post.
--bob p

DM42: β00071 & 00282

Post Reply