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more I/O opto22

Karl_TKarl_T Posts: 7
edited 2010-01-04 21:53 in BASIC Stamp
My winter project is a microcontroller to ventilate and water my
greenhouse/high tunnel.·I plan on using Opto 22 boards and IO blocks for
this project. Parallax makes a module just for this:
http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/27945/List/0/SortField/4/ProductID/289/Default.aspx

(parallax part number 27945 if link above breaks)

I did a count this morning and this is no where near enough IO. Parallax
makes a 40 pin stamp with 32 IO that would work. But they don't make the
above module for it. Is the design for the 27945 public knowledge? Is it possible
to have one custom made? programming the stamps is easy for me but I'm not at
all comfortable with custom circuit board fabrication.

Karl
·

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2010-01-04 14:57
    The design for the Stamp Controller Interface Board is public knowledge. There's a link to the schematic on the webstore page you've included.

    An easy solution might be to just use two Stamp Controller Interface Boards with one Stamp as a master controller and the other as a slave and have them talk to each other. What are you using for timers / sensors?
  • Karl_TKarl_T Posts: 7
    edited 2010-01-04 19:30
    Thanks for the reply. I guess my ignorance shows. The print is no help to me. I ordered a 27945 module to play with. Maybe i can see how to build a custom 27945 between the print and an example. What I'm really looking for is a EE type to build one for me.

    I'm not seeing an easy way to make a master/slave controller. Maybe I just need more experience. The most obvious way to make a master slave would be to have the slave do the actual DC motor control and have the multiple temperature, soil moisture, wind, and operator inputs on the master. But, I'd need 20 I/O plus a couple for comm on the slave. There are four DC motors with outs for power up, power down, ins for upper limit, lower limit, and 1 pulse/revolution for DC motor rotation on each motor. I could go to just one in for both limit switches but I'm still over budget.

    Karl
  • Mike GreenMike Green Posts: 23,101
    edited 2010-01-04 19:55
    Consider using EFX-TEK's Stamp-based controllers and their DC-16 Output Expander. Look here: www.efx-tek.com.
  • Karl_TKarl_T Posts: 7
    edited 2010-01-04 21:53
    BINGO!!

    Thanks for the tip. This should work great. Cheap too.

    Karl
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