multiplexing chips for stamp2?
Does anyone know of a multiplexer for a Stamp2. I vaguely remember
something about an I2c multiplexer somewhere. Basically I need to
be able to control 100 relays in a 10X10 grid, being able to turn
each one off and on individually. I need isolated control for each
relay, so shift registers won't work. Please help. I teach an
electronics class and my students are frequently asking for similar
needs.
something about an I2c multiplexer somewhere. Basically I need to
be able to control 100 relays in a 10X10 grid, being able to turn
each one off and on individually. I need isolated control for each
relay, so shift registers won't work. Please help. I teach an
electronics class and my students are frequently asking for similar
needs.
Comments
> something about an I2c multiplexer somewhere. Basically I need to
> be able to control 100 relays in a 10X10 grid, being able to turn
> each one off and on individually. I need isolated control for each
> relay, so shift registers won't work. Please help. I teach an
> electronics class and my students are frequently asking for similar
> needs.
What you're looking for is the "Philips PCF8574 Remote I/O Expander". You
can put up to eight of these on two BS2 pins for 64 bits of I/O. Use five
more on two other BS2 pins for an additional 40 bits of I/O for a total of
104. Each of these could be used to control the relay drivers.
--
Enjoy,
George Warner,
Schizophrenic Optimization Scientists
Apple Developer Technical Support (DTS)
per device, and each pin can sink/source 25 mA so it is much better for
driving LEDs.
-- Jon Williams
-- Applications Engineer, Parallax
-- Dallas Office
Original Message
From: George Warner [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=QTTDNHLPq3ZEakxvbgVeLcjTh_uok2opr3xO9q0VZAeVJhLzmb0YjBhilzsXHAd1CWwZEl8Kcx44]geowar@a...[/url
Sent: Saturday, April 17, 2004 12:24 PM
To: basicstamps@yahoogroups.com
Cc: Gary Goddard
Subject: [noparse][[/noparse]basicstamps] re: multiplexing chips for stamp2?
> Does anyone know of a multiplexer for a Stamp2. I vaguely remember
> something about an I2c multiplexer somewhere. Basically I need to be
> able to control 100 relays in a 10X10 grid, being able to turn each
> one off and on individually. I need isolated control for each relay,
> so shift registers won't work. Please help. I teach an electronics
> class and my students are frequently asking for similar needs.
What you're looking for is the "Philips PCF8574 Remote I/O Expander".
You can put up to eight of these on two BS2 pins for 64 bits of I/O. Use
five more on two other BS2 pins for an additional 40 bits of I/O for a
total of 104. Each of these could be used to control the relay drivers.
--
Enjoy,
George Warner,
Schizophrenic Optimization Scientists
Apple Developer Technical Support (DTS)