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problem with PP_PCF8574.BSP — Parallax Forums

problem with PP_PCF8574.BSP

verobelverobel Posts: 81
edited 2006-07-18 03:24 in BASIC Stamp
Fellow Stampers;

I purchased the Basic Stamp Plus pack and have been trying some I2C chips. I am having problem with the PCF8574 andd was wondering if anyone could shed some light on the situation. I will attach the code. I believe I have the circuit right and have reviewed it a few times and rebuilt it once. It is built on the Prof. Dev. Board

When I run the program, all I get is:

PCF8574 Demo
Press button to update counter

pressing the button has no effect
BSP
BSP
PP_PCF8574.BSP
4K

Comments

  • dandreaedandreae Posts: 1,375
    edited 2006-07-17 23:33
    Make sure that you use the pull-up resistors (4.7k)·on I/O pins 8 and 9.· Please verify that your button works by testing it using an LED or the Debug terminal.

    Dave

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    Dave Andreae

    Tech Support
    dandreae@parallax.com
    Http://www.parallax.com

    ·
  • verobelverobel Posts: 81
    edited 2006-07-18 03:24
    The 4.7k resistors are in place. 3 other I2C chips are sharing those resistors and the SDA,SCL lines. Switch to on board LED behaves normally. Maybey the chip is bad? Don't have an extra to test that.. Any other debug ideas?
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