Lpc2000

I have no need for the other parts in the family.  I need to read in
5-bits of a 5x4 keypad and 12-bits of a 12-position rotation switch
(5+12=16).

I'm using a Ramtron I2C memory device for my external memory
requirements and RTC.  The part that I'm considering is a FM3164-S.  I
 just checked out the memory section and starting on the RTC.

  Barry

--- In lpc2000@yahoogroups.com, "David Kay" <david.kay@a...> wrote:
> Hi Barry,
> 
> I just happened to have the Philips I2C bus selection guide open on
my
> desktop. Have you looked at the other devices in the range:-
> 
> ################################################
> 
> I2C General-purpose I/O (GPIO) Expanders
> 
> - Extend GPIO from I2C or SMBus
> 
> - Connect parallel I/O to serial I2C or SMBus
> and provide I/O expansion
> 
> - Quasi output: upper transistor is on for half
> a clock cycle and then held up by a weak
> current source (25-mA sink)
> 
> - True Output: configurable as input or output
> with polarity inversion (push/pull with
> 25-mA sink and 10-mA source)
> 


> Quasi Output (Weak Current Source)
> 
> PCA9500 8-bit with 2-kbit EEPROM
> PCA9501 8-bit with 2-kbit EEPROM, Interrupt
> PCA9558 8-bit w/ 5-bit DIP, 2-kbit EEPROM
> PCF8574/74A 8-bit with Interrupt
> PCF8575/75C 16-bit with Interrupt
> 
> True Output (Configurable Push/Pull)
> 
> PCA9536 4-bit with Interrupt
> PCA9537 4-bit with Interrupt, Reset
> PCA9538 8-bit with Interrupt, Reset
> PCA9539 16-bit with Interrupt, Reset
> PCA9534/54/54A 8-bit with Interrupt
> PCA9535/55 16-bit with Interrupt
> PCA9557 8-bit with Reset
> 
> ############################################
> 
> Samples of any of these devices should be easy to source from your
local
> Philips Disti.
> 
> Best regards,
> 
> David Kay
> www.adilam.com.au
>  
> 
> -----Original Message-----
> From: lpc2000@yahoogroups.com [mailto:lpc2000@yahoogroups.com] On
Behalf
> Of javida13
> Sent: Tuesday, 6 September 2005 12:45 p.m.
> To: lpc2000@yahoogroups.com
> Subject: [lpc2000] Port Expander
> 
> I'm looking for an I2C Port Expander for both 8 and 16-bits,
> preferably with light pull-ups when configured as inputs.
> 
> I have found two possible devices:
>   Philips  PCA9555  (16-bits with pull-ups)
>   Microchip MCP23016 (16-bits w/o pull-ups)
>             MCP23008 (8-bits w/o pull-ups)
> 
> I was able to get some samples of the Microchip part but I'm having
a
> problem with the Philips.  Anyone have experience with using a port
> expander and if so, what device was chosen?
> 
> Thanks,
>   
>   Barry
> 
> 
> 
> 
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