Keypad Help - Electronic Circuits Projects Diagrams Free

GForce2010 · 11th May 2008, 10:15 PM

I've been slowly working my way through Nigel's PIC tutorials and i'm currently working on a project to make a code lock so i've wired up a 3x4 matric keypad the exact same way that's on the site and used the correct tutorial programme but it doesn't work as it should.

I know for certain i've wired it all up the EXACT same way but when i press the keys i get the following results.

1,2,3 don't work
Press 4 and it displays B
Press 5 and it displays 9
Press 6 and it displays 6
Press 7 and it displays 0
Press 8 and it displays 8
Press 9 and it displays 5
Press 0 and it displays A
Press * and it displays 7
Press # and it displays 4

so as you can imagine i'm a bit confused.

Any help would be greatly appreciated.

OY2L · 11th May 2008, 10:58 PM

Nigel's Keypad is a 4x4 matrix and it not have the * and#

GForce2010 · 11th May 2008, 11:01 PM

i know that so the code brings up A and B rather that * and #, that's something i would alter later but none of the keys are bringing up the right number. and i've done the alteration in the code that Nigel states to do if you're only using a 4x3 keypad.

OY2L · 11th May 2008, 11:14 PM

What No tutorial are you trying 9.?

GForce2010 · 11th May 2008, 11:21 PM

9.2, the code lock one

OY2L · 11th May 2008, 11:59 PM

Are the numbers on your keypad arranged just as Nigel's ? and is it a matrix keypad and not a decimal ? I think it may be a wiring problem, i'am just trying tut 9.2 here and everything works great.

Pommie · 12th May 2008, 12:16 AM

The 3x4 keypads have a rather strange pin out. Looking from the top it goes, C1, R0, C0, R3, C2, R2, R1.

Mike.

OY2L · 12th May 2008, 12:36 AM

Maybee it is like this.

**Nigel Goodwin** · 12th May 2008, 08:10 AM

If you check my tutorial, it uses a lookup table to allocate the correct code for each button - all you need to do is alter the table order to get the responses you want.

sachin.kolkar · 12th May 2008, 08:54 AM

plz check your keypad connections. Did u ground the all rows through 10k or more valued resistor , iwas face the same problem...........

GForce2010 · 12th May 2008, 10:31 AM

as i said i've wired it up exactly like Nigels schemetic. it is a matrix and i've worked out what each pin is. As Mike wrote it does have a strange pin layout due to the circuit tracks.

Thanks for the help Nigel........i still find it confusing that although i've copied it exactly it's not working for me........

**Nigel Goodwin** · 12th May 2008, 10:41 AM

Quote:

Originally Posted by GForce2010

as i said i've wired it up exactly like Nigels schemetic. it is a matrix and i've worked out what each pin is. As Mike wrote it does have a strange pin layout due to the circuit tracks.

Thanks for the help Nigel........i still find it confusing that although i've copied it exactly it's not working for me........

It depends how your keypad is actually wired inside, which is why I used a lookup table to convert it.

GForce2010 · 12th May 2008, 10:53 AM

I've just been looking at the tutorial again and i think there might be a mistake in there.

The actual schemitic for the keypad interface board shows the pull up resistors on the the Row lines but in the tutoriual itself it says the pull up resistors are on the Col lines. Which is the correct one??

Pommie · 12th May 2008, 11:27 AM

Nigel seems to have his rows and columns switched around in the software. Wire the keypad as in Nigel's hardware and don't remove the two lines of code but do include the 4th pullup resistor. The table may need switching around but at least all keys will work.

Mike.

GForce2010 · 12th May 2008, 11:36 AM

i've just got it working by swapping all the interface connectors around.

looks like in the diagram it's marked row 1 - 4 then col 1-4 but for it to work i had to connect it col 4-1 then col 4-1

anyway it's now working fine.

Think you should have a look at the keypad interface diagram Nigel.

Thanks for all the help

11th May 2008, 10:15 PM	(permalink)
GForce2010 New Member	Keypad Help I've been slowly working my way through Nigel's PIC tutorials and i'm currently working on a project to make a code lock so i've wired up a 3x4 matric keypad the exact same way that's on the site and used the correct tutorial programme but it doesn't work as it should. I know for certain i've wired it all up the EXACT same way but when i press the keys i get the following results. 1,2,3 don't work Press 4 and it displays B Press 5 and it displays 9 Press 6 and it displays 6 Press 7 and it displays 0 Press 8 and it displays 8 Press 9 and it displays 5 Press 0 and it displays A Press * and it displays 7 Press # and it displays 4 so as you can imagine i'm a bit confused. Any help would be greatly appreciated. Last edited by GForce2010; 11th May 2008 at 10:43 PM.

12th May 2008, 08:10 AM	(permalink)
Nigel Goodwin Super Moderator	If you check my tutorial, it uses a lookup table to allocate the correct code for each button - all you need to do is alter the table order to get the responses you want. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

12th May 2008, 08:54 AM	(permalink)
sachin.kolkar Experienced Member	plz check your keypad connections. Did u ground the all rows through 10k or more valued resistor , iwas face the same problem........... __________________

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11th May 2008, 10:58 PM	(permalink)
OY2L Experienced Member	Nigel's Keypad is a 4x4 matrix and it not have the * and#

11th May 2008, 11:01 PM	(permalink)
GForce2010 New Member	i know that so the code brings up A and B rather that * and #, that's something i would alter later but none of the keys are bringing up the right number. and i've done the alteration in the code that Nigel states to do if you're only using a 4x3 keypad.

11th May 2008, 11:14 PM	(permalink)
OY2L Experienced Member	What No tutorial are you trying 9.?

11th May 2008, 11:21 PM	(permalink)
GForce2010 New Member	9.2, the code lock one

11th May 2008, 11:59 PM	(permalink)
OY2L Experienced Member	Are the numbers on your keypad arranged just as Nigel's ? and is it a matrix keypad and not a decimal ? I think it may be a wiring problem, i'am just trying tut 9.2 here and everything works great.

12th May 2008, 12:16 AM	(permalink)
Pommie Experienced Member	The 3x4 keypads have a rather strange pin out. Looking from the top it goes, C1, R0, C0, R3, C2, R2, R1. Mike.

12th May 2008, 10:31 AM	(permalink)
GForce2010 New Member	as i said i've wired it up exactly like Nigels schemetic. it is a matrix and i've worked out what each pin is. As Mike wrote it does have a strange pin layout due to the circuit tracks. Thanks for the help Nigel........i still find it confusing that although i've copied it exactly it's not working for me........

12th May 2008, 10:53 AM	(permalink)
GForce2010 New Member	I've just been looking at the tutorial again and i think there might be a mistake in there. The actual schemitic for the keypad interface board shows the pull up resistors on the the Row lines but in the tutoriual itself it says the pull up resistors are on the Col lines. Which is the correct one??

12th May 2008, 11:27 AM	(permalink)
Pommie Experienced Member	Nigel seems to have his rows and columns switched around in the software. Wire the keypad as in Nigel's hardware and don't remove the two lines of code but do include the 4th pullup resistor. The table may need switching around but at least all keys will work. Mike.

12th May 2008, 11:36 AM	(permalink)
GForce2010 New Member	i've just got it working by swapping all the interface connectors around. looks like in the diagram it's marked row 1 - 4 then col 1-4 but for it to work i had to connect it col 4-1 then col 4-1 anyway it's now working fine. Think you should have a look at the keypad interface diagram Nigel. Thanks for all the help