48 outs needed
I am finishing up a design that takes an RS232 signal and controls 48(3 banks of 16) relays independantly. Since a single Prop can't run 32 relays and still communicate on 2 pins at the same time, and the fact that a single instruction set manages 16 relays at a time, that means I will need 3 Propellers to manage 3 x 16 banks. This method is easily doable, but I was wondering if there is a more efficient way to do this using only one Propeller and some means to break out 16 pins off one serial I/O pin. Only one relay is on at a time, so some type of 1 of 16 switch would work, I am just not aware of such a device that could receive a command from the Prop off a single pin and turn on one of 16 pins. Any suggestons would be great. Thanks
Comments
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Who says you have to have knowledge to use it?
I've killed a fly with my bare mind.
Cypress have I2C expanders up to 100pins with 16PWM.
Gavin
I think that, like CJ said, the 74HC595 plus some BS170 (FET), could be the best and cheap solution.
Regards.
Alberto.
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www.allegromicro.com/sf/6832/
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Tracy Allen
www.emesystems.com
The 8255 is $5 per chip. To drive 48 relays you would need two 8255's and six ULN2803's. It would work - may not be the simplest solution though.
16 bit remote I2C and SMBus·I/O expander.
[*]16 individually addressable pins [*]Each pin configurable for input or output [*]Interrupt output pin
Mouser Part# 595-PCF8575W
you can find this same part at sparkfun.com as a Breakout Board.·With the·PCF8575 I2C Expander IC mounted to the board.
SKU#:·Break-PCF8575
http://www.sparkfun.com/commerce/product_info.php?products_id=8130
Hope this helps,
IAI-Captain
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IAI (Indigenous Alien Intelligence),
The New View on Machine Intelligence.
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Post Edited (originator) : 1/7/2007 11:52:35 PM GMT
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Who says you have to have knowledge to use it?
I've killed a fly with my bare mind.
The shifout in BS2 functions can perfectly send the data to the 595's.
Regards.
Alberto.
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