Down\Left Diagonal Final Keytest UPDATE page 3

[Guest lawsonium]

Sounds promising but, the way you describe your notion of the problems cause it sounds like you are trying to fix it with some kind of physical repair. I was just thinking that as you are able to hear and feel both the left and the down buttons being 'clicked' when you attempt a diagonal move it doesn't suggest a physical problem to me.

However you have more info on this than me so I'm not fully informed, so I await your findings with a worm on my tongue :-) (Baited Breath!!!)

Matt.

[Guest ClintEastman]

What's the word then awarner?

[Guest awarner [MVP]]

:oops: sorry been a bit on the busy side, will hopefully post more about it tonight.

[Guest awarner [MVP]]

Right ok the information I was given explained that the fault lies with poor moulding of the case and silicone used to stick the buttons to the rubber keypad membrane.

Unfortunately this is not the case :)

I have opened up the phone and made a few experiments with the

keypad case, membrane and buttons and could not find any obvious defects.

I still have a few things to try and if I do find a solution I will post about it.

[Guest awarner [MVP]]

If the problem is hardware it an internal fault on membrane and not accessable. I've also tested the commands with a nice app and it will only acknowledge left or down by them selves and not both at the same time.

[Guest skinman_uk]

Well thats why I'm getting hammered at total soccer :x

Tested it and failed the dreaded diagnol down/left!!

[Guest awarner [MVP]]

Better than the E200 which does not have diagonals at all :/

[Guest awarner [MVP]]

I thought I had posted this ages ago but does not look like it :oops:

Here you go, nice key assignment conflicts

3 and UP

5 and UP

6 and Forward

7 and UP

8 and Right

* and Right

End Call replicates button 3

Answer replicates Soft 1

Home replicates Soft 1

Volume UPDown replicates Soft 1

Power replicates Soft 1

Back replicates Soft 1 (but back commands overwrite the fire button)

[Guest awarner [MVP]]

UPDATE

After stripping the keypad to it's bare circuit board I can now explain why the keypad is faulty.

The final conclusion is not cut and dry but pretty close.

The key press conflicts are split mainly between the same two outputs (there is only one conflict that does not follow this rule)

The DownLeftAction etc all share the same signal output. So when the circuit is made the phone registers the action but will not accept a new input command until the key up signal is received.

So for an example if you press and hold Down then press Left and release Down the phone still thinks that Down is being pressed. you can then continue to press other keys that share the same output in the method above and the phone will still think the first key press (Down in this case) is still being made.

So at the moment until a key up signal is received the phone cannot process another key press on the same output.

Now this points towards hardware fault, but it could still be cured with a possible driver hack, (but this is not definite) so the key down is acknowledged and allows another input without having to wait for the key up signal.

The other possible reason is that there is too much of a current drain on the same output for it to latch properly if more than one key is pressed.

and finally for those who like to know what voltage the keypad is, I measured it at 2.86v :)

[Guest Bonzo]

Hmmmm Well I haven't been keeping abreast of this problem lately but it seems that the keyboard matrix U are describing relies on a limited number of return lines to the decoder... feel free to correct me on this as i could be reading this wrong, I work better with the drawings than trying to draw it in my mind!!! lol...

So if this is a limited number of lines, say for arguments sake all of the keys are split between just two lines, it then has to rely on a very specific voltage level to determine which button is being pressed... as such this is the result of the series resistance between each switch.... Now if that is right the I doubt it could operate in the way U describe with the down key pressed then the left key pressed and the down key released because this would still produce a rise or fall in the overal voltage seen at the decoder which it would recognise as being the switch to which this level is assigned!!!

However, and I could VERY easily be wrong on this point, 2.86V seems a VERY strange value!!! 3V would seem to me to be more realistic, but I know 0.14V may not seem like much but in the keyborad map I have described where it is dependant on voltage drop and resistance at some point in the chain this could become significant!!! So could it be, if i'm right in my reading of your description of the circuit, that there is either a regulation or resistance fault in the circuit that could cause this scenario???

[Guest awarner [MVP]]

The InputOutput are split between ten terminals on a twelve pin connector

so you have five inputs and five outputs terminals with the other two for

earthing.

As for testing the resistance of every switch, my Fluke is not that accurate

:oops: I'm fairly sure the keypad is not working off resistance as the

inputoutput of each switch is unique.

[Guest Bonzo]

Right that's OK it's not the system I was first thinking but it is in fact a full matrix type keyboard... Even better that's a simpler system to understand and nope if it is a full matrix then it wouldn't come down to voltage drop or resistance as each keypress is seen at two locations on the decoder IC from which it determines which key is being pressed 8)

[Guest awarner [MVP]]

From your knowledge so you think that a driver update could fix this

problem, or could a simple hack be possible?

[Guest mcwarre]

However, and I could VERY easily be wrong on this point, 2.86V seems a VERY strange value!!!

You're right, you're wrong :wink: :wink: :wink:

2.86V is perfectly acceptable as a level '1' in digital circuit logic!

[Guest Bonzo]

yep I agree it is acceptable as a logic level 1 however in the circuit I was describing with limited return lines dependant on the decoder interpreting a voltage drop across a series resistor & switch it would have been a strange starting voltage...

As for a software update solving the problem I would say most likely yes... with a full matrix eaxh switch is located by way of the decoder/processor seeing it on two lines... the scan output line where the mark/space ratio of the wave being output can be varied for each output line and in the input line where the waveform appears having passed thru the switch. But this only stands up if it's not a monumental design error where two switches required for the action are on the same return line!

Once again tho without the actual schematic in front of me I can't say anything 100% as I'm terrible trying to put these things together in my head!!! But I would say yeah an update could/should sort the problem :)

[Guest awarner [MVP]]

But this only stands up if it's not a monumental design error where two switches required for the action are on the same return line!

This could be a problem then as the main topic of this thread, the DownLeft as well as the Action button share the same return line

(ie output side of the switch)

[Guest Bonzo]

Hmmm it's one of those situations where if I could see the schematic for the matrix layout for the keybord I could say yah or nah in seconds!!!

But I would find it so hard to believe that a circuit design as simple and as frequently used as a keyboard matrix could be subject to such a simple design error!!! But there again that doesn't mean it's not possible either

[Guest awarner [MVP]]

I can post each individual key inputoutput if that's any help?

need to take the phone apart again to get the actual pinouts

relating to the connector so it may be a few days.

[Guest Bonzo]

That might be a help if U could post them or pm me with them I should then be able to draw up the schematic and work it out from that... but it could take me a while as I'm flying out to the states soon for a few weeks

[Guest awarner [MVP]]

If you only need what keys are linked to each other then I can do that tomorrow.

But if you need to know pinouts on the connector then I'll need a few days.

[Guest Bonzo]

Unfortunately I would need to know the connector pin-outs too :)

[Guest awarner [MVP]]

Ok easy enough,Time to rip the phone apart again :twisted:

[Guest awarner [MVP]]

Right microscope used pinouts checked :D/

There is not an obvious indication to what pin 1 is so this may be upside down.

Here you go :)

Pin 1 = Input Soft 1, Soft 2, Up, Left, Right

Pin 2 = Input Answer, Down, End Call, Home, Back

Pin 3 = Input 1, 2, 3, 6

Pin 4 = Input 4, 5, 8, 9

Pin 5 = Input Action, 7, *, 0, #

Pin 6 = Common

Pin 7 = Common

Pin 8 = Output Up, End call, Back, 3, 5, 7, 8

Pin 9 = Output Soft 2, Answer, 2, 4, #

Pin 10 = Output Soft 1, 1, 9, 0

Pin 11 = Output Right, Home, 6, *

Pin 12 = Output for Left, Down, Action

Pin 13 = Led

Pin 14 = Common

[Guest Bonzo]

OK thanx that seems like a simple enough key matrix layout reading it... I'll knock up a quick schematic and post the result here in the next day or two :)

[Guest lawsonium]

Damn, this is moving nicely, you guys are doing a true service :)

Well done guys.

Matt