Keyboard debouncing

If you're having problems with the hardware of a DM42, post about them here.
reavy
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Location: Phoenix, AZ

Re: Keyboard debouncing

Post by reavy » Sat Feb 24, 2018 8:32 pm

I had this happen with the ‘2’ key immediately out of the box. It’s definitely not an auto repeat issue because I got two 2s with one press of the button, no delay at all.

It has only happened once and only with the one key, but unfortunately it’s cost some of my confidence in the machine, and I am careful to validate my inputs visually rather than only trusting button clicks.

toml_12953
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Location: Malone, NY USA

Re: Keyboard debouncing

Post by toml_12953 » Sun Feb 25, 2018 6:41 am

reavy wrote:
Sat Feb 24, 2018 8:32 pm
I had this happen with the ‘2’ key immediately out of the box. It’s definitely not an auto repeat issue because I got two 2s with one press of the button, no delay at all.

It has only happened once and only with the one key, but unfortunately it’s cost some of my confidence in the machine, and I am careful to validate my inputs visually rather than only trusting button clicks.
I have one button (X< >Y) that clicks just like the rest but nothing happens unless I then press just a little harder. Then X and Y are swapped as they should be. I can't rely on the tactile feedback for that key. Unfortunately, it's in the middle of the matrix so I'd have to peel back a lot of membrane to get at it. The chances I'd mess up another key are great!

Addendum: Fool that I am, I tried the peeling back anyway. That sheet is tough stuff! All the domes stuck just where they were and the contacts under the X<>Y dome looked fine. No foreign material or anything. All the domes look dead center over their contacts. After I put the calculator back together, the X<>Y key seems to work a little more reliably. Of course that could be either me subconsciously pressing that key just a little harder or wishful thinking on my part.
Tom L

¡spuǝıɹɟ uɐılɐɹʇsnɐ ʎɯ llɐ oʇ ıH
DM42 SN: 00025 (Beta)
SN: 00221 (Shipping)

kintekobo
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Joined: Thu Jun 28, 2018 12:35 pm

Re: Keyboard debouncing

Post by kintekobo » Tue Jul 03, 2018 11:01 am

Following on from the posts here I am inclined to agree that there is something in the software that is causing the keyboard problems. I have just received my DM42 and while trying to follow along with some of the examples in the user manual I found it quite frustrating that what I was typing in wasn't the same as was appearing on the calculator.

I ran a rather long and boring test where I pressed every key at a rate of about one press per second for about 60 seconds each and observes the result. I was getting missed keystrokes and/or multiple presses on just about every key at some point. It seems to me that the missed keys are most likely because the processor is busy on another task and miss the interrupt since I was very careful to make each press identical The multiple keys are most definitely due to some form of key bounce since I have it on slow repeat.

I haven't noticed any key fail to register or multiple trigger on my DM41L which makes me wonder if there is a difference in the keyboard matrix or the code used to implement the keyboard routine that could point to the problem. As it stands the DM42 is very difficult to use as it behaves erratically and can be very frustrating to use.

nmihiylov
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Location: Ohio

Re: Keyboard Debouncing - NOOB Question

Post by nmihiylov » Wed Oct 10, 2018 7:44 pm

So - I am new to the Forum +/- week, and have my new DM42 in my possession, and I have been obsessed with the various topics in this forum. So now I don't know if I am over reacting, if what I am about to explain is normal, or if I actually have an ENTER key issue.

When entering a number, then hitting ENTER, the number appears both in the "X" Register and the "Y" Register. If I proceed to enter a second number it types into the "X" register.

I was thinking that once the ENTER key is used, it moves the number from the "X" register to the "Y" register then displays a ")" in the "X" register?
Slow Auto-repeat has no effect on this process - on or off.

I am thinking that there is no issue (?) but wanted to validate with the more experienced users. This is the first calculator that I have owned that displays more than the "X" register so this may or may not be normal.

Please advise -
Nick Mihiylov
DM42
SN# 03787

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Walter
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Re: Keyboard Debouncing - NOOB Question

Post by Walter » Wed Oct 10, 2018 10:25 pm

nmihiylov wrote:
Wed Oct 10, 2018 7:44 pm
When entering a number, then hitting ENTER, the number appears both in the "X" Register and the "Y" Register. If I proceed to enter a second number it types into the "X" register.
This is exactly what ENTER should do: close entry in X and copy x into Y, after moving previous y into Z after previous z went into T (previous t is lost). Or, since a picture tells a thousand words:
.
Push.PNG
Push.PNG (54.91 KiB) Viewed 145 times
DM42 SN: 00041 --- Follower of Platon.

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

nmihiylov
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Re: Keyboard Debouncing - NOOB Question

Post by nmihiylov » Wed Oct 10, 2018 11:59 pm

Walter wrote:
Wed Oct 10, 2018 10:25 pm
nmihiylov wrote:
Wed Oct 10, 2018 7:44 pm
When entering a number, then hitting ENTER, the number appears both in the "X" Register and the "Y" Register. If I proceed to enter a second number it types into the "X" register.
This is exactly what ENTER should do: close entry in X and copy x into Y, after moving previous y into Z after previous z went into T (previous t is lost). Or, since a picture tells a thousand words:
.
Push.PNG
Thank You Walter - figures that I was over-reacting from reading all of these posts. I did then get a chance to try it out on my Free42 calculator on my iPad and saw the number I entered in both the X and Y register.

I think that I will quit reading the Problem and Issues part of the forum as I have a great calculator!
Nick Mihiylov
DM42
SN# 03787

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ijabbott
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Location: Manchester, UK

Re: Keyboard Debouncing - NOOB Question

Post by ijabbott » Mon Oct 15, 2018 9:52 pm

nmihiylov wrote:
Wed Oct 10, 2018 7:44 pm
When entering a number, then hitting ENTER, the number appears both in the "X" Register and the "Y" Register. If I proceed to enter a second number it types into the "X" register.
That's normal for the classic T/Z/Y/X register RPN calculators.

You can also press EXIT after entering a number, and it will only change the X register without disabling automatic stack lift.

This illustrates the difference in stack behaviour between ENTER and EXIT:

Code: Select all

T: ?     | T: ?
Z: ?     | Z: ?
Y: ?     | Y: ?
X: ?     | X: ?
         |
> 1000   | > 1000
         |
T: ?     | T: ?
Z: ?     | Z: ?
Y: ?     | Y: ?
X: 1000_ | X: 1000_
         |
> ENTER  | > EXIT
         |
T: ?     | T: ?
Z: ?     | Z: ?
Y: 1000  | Y: ?
X: 1000  | X: 1000
         |
> 2000   | > 2000
         |
T: ?     | T: ?
Z: ?     | Z: ?
Y: 1000  | Y: 1000
X: 2000_ | X: 2000_
         |
> ENTER  | > EXIT
         |
T: ?     | T: ?
Z: 1000  | Z: ?
Y: 2000  | Y: 1000
X: 2000  | X: 2000
         |
> 3000   | > 3000
         |
T: ?     | T: ?
Z: 1000  | Z: 1000
Y: 2000  | Y: 2000
X: 3000_ | X: 3000_
         |
> ENTER  | > EXIT
         |
T: 1000  | T: ?
Z: 2000  | Z: 1000
Y: 3000  | Y: 2000
X: 3000  | X: 3000
         |
> 4000   | > 4000
         |
T: 1000  | T: 1000
Z: 2000  | Z: 2000
Y: 3000  | Y: 3000
X: 4000_ | X: 4000_

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Walter
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Re: Keyboard Debouncing - NOOB Question

Post by Walter » Tue Oct 16, 2018 3:56 am

ijabbott wrote:
Mon Oct 15, 2018 9:52 pm
You can also press EXIT after entering a number, and it will only change the X register without disabling automatic stack lift.

This illustrates the difference in stack behaviour between ENTER and EXIT...
Never thought of using EXIT this way. Learned something new. Thanks!
DM42 SN: 00041 --- Follower of Platon.

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

keithdalby
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Re: Keyboard Debouncing - NOOB Question

Post by keithdalby » Tue Oct 16, 2018 4:04 am

ijabbott wrote:
Mon Oct 15, 2018 9:52 pm
You can also press EXIT after entering a number, and it will only change the X register without disabling automatic stack lift.
I can't think of a situation where that would be useful.

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ijabbott
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Re: Keyboard Debouncing - NOOB Question

Post by ijabbott » Tue Oct 16, 2018 7:28 am

keithdalby wrote:
Tue Oct 16, 2018 4:04 am
ijabbott wrote:
Mon Oct 15, 2018 9:52 pm
You can also press EXIT after entering a number, and it will only change the X register without disabling automatic stack lift.
I can't think of a situation where that would be useful.
It makes entering numbers on the stack behave more like RPL calculators (apart from the limited stack size).

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