Keypad for bs2p

Julianto

Sorry mike, i'm first to join this forums. I new in bs2p40 can you give me sample program for keypad 4*4.
Thanks for all

Mike Green

Nuts and Volts Column #22 discusses this and has sample code: www.parallax.com/tabid/272/Default.aspx

Mike Green

Please delete your duplicate message. There's an X icon in the upper righthand corner of the message that will do this.

xanatos

If you'd like to save pins on that 4x4 arrangement - and if your application would benefit - there's a great 4x4 encoder chip - 74C922 - it takes in the matrix of the keys and turns it into a 4 bit hex output. The few times I've used a 4x4 keyboard, this is what I've used as for me, usually I/O pins on the stamp are at a premium - even on the p40!

Dave

Chris Savage

Two duplicate messages deleted.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Engineering

Dave-W

Julianto
I have been using another IC for Key Scan.
Check it out. Makes things easy and only two pins on the stamp.
EDE1144 from E-Lab Inc.
Dave



▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Dave W.

Julianto

Thanks Mike, i am interest to use encoder chip 74C922 Nuts and Volts Column #97, but i have problem the program doesn`t work.
I try to modification program but i use output is LED. I have question why column 4 in keypad not work, what you think the problem on skematic or the program.(Skematic is same whit nuts and volt column#97)

Mike Green

I can't read your schematic file.

I think column 4 is the "extended" characters "A", "B", "C", and "D". The bit variable "showExt" has to be set to non-zero for the program to display these with the DEBUG statements.

If that's not it, then you probably have a wiring error. Very carefully check the connection for column 4 from the keypad to the 74C922.

Julianto

Oke mike i will follow you sugest.
Thanks Mike.

Lab Rat

mike if you dont have it try getting microsoft word preferably an older edition it opens those files right up

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Parallax posesses power beyond belief.

Believe in it.