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Memory Chip Wiring? — Parallax Forums

Memory Chip Wiring?

Kirk FraserKirk Fraser Posts: 364
edited 2011-06-15 18:47 in Propeller 1
In the Propeller Tool when I run F11 Load EEPROM I get an error that it was unable to load to memory. Since the program compiles under F10 I'm assuming there must be a wiring error. Here are two views, can you spot my mistake? I have oriented the memory chip with pin 1 down relative to the Prop's pin 1 for ease in wiring. I read advice to use F11 to get debug information through the serial terminal. Thanks for looking.
100_2037.jpg
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100_2035.jpg
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Comments

  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-06-13 23:34
    It looks like you have the clock and data pins switched.

    Edit: I often position the EEPROM upside-down so the clock and data line up without needing to cross the lines. Leave your 10K resistor on the data line (as it is now).
  • Kirk FraserKirk Fraser Posts: 364
    edited 2011-06-14 09:54
    Switching the crossed wires produces the message:
    "EEPROM programming error on COM3:

    The program doesn't work yet but compiles using F10.
    Any further suggestions? Here's my lashed together code so far...

    Test Code.spin
    spin
    spin
    Test Code.spin
    3K
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-06-14 10:20
    Your pull-up resistor isn't connected to 3.3V. It looks like you missed it by one hole.
  • ratronicratronic Posts: 1,451
    edited 2011-06-14 12:08
    You should also use resistor's in series with your led's.
  • Kirk FraserKirk Fraser Posts: 364
    edited 2011-06-14 13:27
    Duane, It works! Thanks. One of the wires I uncrossed wasn't conducting so I changed holes by one.

    ratronic, The resistors for the LED's flank the push button. They work!
  • Duane DegnDuane Degn Posts: 10,588
    edited 2011-06-14 14:14
    Great! Glad to hear it. The Prop is a lot of fun.
  • Mark_TMark_T Posts: 1,981
    edited 2011-06-14 19:24
    BTW you don't appear to have decoupling capacitors on the Prop or the EEPROM - they are not optional components!
  • Kirk FraserKirk Fraser Posts: 364
    edited 2011-06-14 21:07
    Mark, My circuit is as shown on page 27 of Propeller Education Kit Labs: Fundamentals.
    What are decoupling capacitors and where do they go? At present, my board works!
  • Mark_TMark_T Posts: 1,981
    edited 2011-06-15 18:47
    You might want to checkout Grumpy Mike's tutorial: http://www.thebox.myzen.co.uk/Tutorial/De-coupling.html

    Without decoupling on the supply for high speed logic circuitry things tend to work by luck, rather than design. This is especially true once you start switching more than a few milliamps at logic speeds - general rule of thumb is 0.1uF ceramic decoupling capacitor within a cm or so of each logic IC.
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