I did a device a while back which does 50 keys (5x10). It scans constantly, does N-key rollover and stacks commands - provides a 6 bit word output along with a data ready strobe and an 'Any key down' line. I did it to replace a chip I couldn't get any longer (KB9600) which did all this in hardware (96 key tho') Jim --- ---------------------------------------------------------------------------- -------------------- Jim Main | Eastcom Broadcast Developments jim.main@eastcom.co.uk| custom hardware and software www.eastcom.co.uk ---------------------------------------------------------------------------- ----------------- ----- Original Message ----- From: White Horse Design To: Sent: 01 November 1999 12:45 Subject: Re: [OT] Keypad IC added to lineup > At 23:50 30/10/1999 , you wrote: > >4x4 Keypad Encoder IC > > > >We're pleased to announce an addition to our EDExx Family of integrated > >circuits. The EDE1144 4x4 Keypad Encoder IC is designed to interface a 4x4 > >(or smaller) multiplexed keypad to a host microcontroller. Outputs are > >serial (2400/9600 Baud) or parallel. > > > >The EDE1144 features key debouncing and key auto-repeat when held. It is > >electrically (EMI) quiet, scanning the keypad only once when a keypress is > >detected, rather than a continual scan. A beeper drive signal provides > >tactile feedback to the operator upon keypress. > > > >Available in 18 pin DIP or SOIC packages, the EDE1144 sells for $7 US > >Dollars quantity 1, and $3.25 1K pricing. A datasheet and full pricing > >information is available at http://www.elabinc.com/chips.htm > > We are interested in a device that can handle 20 or 24 keys for (ahem!) an > automotive application. We need a telephone keypad and keys around an LCD > so 16 are just not enough. > > We currently use a PIC 16C54 for LCD drive and keypad scanning, using HC164 > shift registers to scan more rows (with enough of 'em we can scan 240 keys!!) > > It would also be nice if there were a version of the 74HC922 that could > handle more than a 4x4 matrix ... > > Regards > > Adrian > --- > WWW WWW Adrian Gothard > WWW WW WWW White Horse Design > WWWWWWWWWW +44-385-970009 (Mobile/SMS), +44-118-962-8913/4 (voice/fax) > WWWW WWWW whd@zetnet.co.uk, http://www.users.zetnet.co.uk/whd > --- > Developers of GPS satellite-based tracking systems for vehicles/helicopters >