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I/O Expander — Parallax Forums

I/O Expander

crgwbrcrgwbr Posts: 614
edited 2006-09-01 17:51 in BASIC Stamp
I'm looking for an 8 bit digital I/O expander.· I was origanlly going to use the PCF8574, but then I remembered that·it uses I2C communication, and I'm using a BS2, not a BS2p, therefore I can't use it.· Does anyone have a recomended replacment?· Also I herd somwhere that you could use I2C with the BS2, but it took a lot of programming.· Has anyone heard of this.

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Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-09-01 16:54
    I2C can be used with the BASIC Stamp, but it takes a bit more code to do it.· An example can be found at the following link (The sample source code includes a BS2 file).· Depending on whether you need I/O or just extra inputs or outputs, you could use a simple shift register to expand your I/O.· Examples can be found at the second link, bottom of the page, free PDF of the Stamp Works Manual.· Look under Expanded Digital Inputs/Outputs.· Take care.

    http://www.parallax.com/detail.asp?product_id=602-00013

    http://www.parallax.com/detail.asp?product_id=27220

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • crgwbrcrgwbr Posts: 614
    edited 2006-09-01 17:04
    Thank you, all I really need are outputs, it's going on a motor controller (It seemed wrong to use half your I/O pins just to control two motors).

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  • NewzedNewzed Posts: 2,503
    edited 2006-09-01 17:08
    I have a program for controlling an I2C MCP23016 Port Expander with a BS2.· You could use the outputs of the 23016 tp drive a Darlington array such as the ULN2803.· You are welcome to the program if you would like it.

    Sid

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    Sid Weaver
    Do you have a Stamp Tester yet?
    http://hometown.aol.com/newzed/index.html

    ·
  • crgwbrcrgwbr Posts: 614
    edited 2006-09-01 17:51
    Thanks Anyway, but I already have 4 PCF8574 on order. I'm still really confuzed about using I2C, I've never worked with the SHIFTIN and SHIFTOUT commands. I'll provide the link to a Nut & Volts article on using the PCF8574 with the BS2P; if anyone could help explane using it with the BS2, your help will be greatly appeaciated.

    http://www.parallax.com/dl/docs/cols/nv/vol3/col/nv79.pdf

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