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BeMicroCV EEPROM Modification, Peripheral Pin Selection - Page 2 — Parallax Forums

BeMicroCV EEPROM Modification, Peripheral Pin Selection

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  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2015-08-15 11:30
    Thanks for mentioning the block structure issue. I am aware of it, and have yet to sit down and review the PDFs to verify the 2Mbit is okay or no good.

    I really would like to get the largest I2C EEPROM that will work. It is silly to spend all this money on shipping and not get the best.
    +++++
    Meanwhile, I checked my DIY daughterboard, found one build error, fixed that and attempted to load the 24LC256 EEPROM.

    So far it givs a loading error, "EEPROM Verify error". But it will load the program to RAM and run it (I am running pfth Forth V0.83 for trials). I wonder if BST expects only a 24lc512 device.

    It seems I have more work to do. Perhaps I should include a decouple capacitor on the daughter board. And I might have to add a second 10K pull-up as I provide only the one shown in the Propeller Manual typical schematic. Or maybe I should try another EEPROM. grrrrrr....

    At least the PropPlug interface is right and communicating at 115200 baud.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2015-08-16 12:09
    Opps...........
    Well, it seems that I wired half of the EEPROM pins in a mirror image of what they should be. The 3.3V is attached to SDA, not VCC.

    A typical error of wiring from scratch. (And the main reason I keep these kinds of projects small and print a circuit board for anything ambitious.)

    ++++++
    Time to rebuild and report back later.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2015-08-16 12:13
    No joy in Mudville....

    I rewired my DIY daughter board and it still would not program the EEPROM. So I took advantage of pfth Forth 0.83 with some added words that make testing easy.

    I have the following...
    output
    input
    high
    low

    All I do is preface with the pin number

    So to test PIN 28 I do this with a VOM attached to PIN 28 and V3.3

    28 output (voltage changes to 3.28 indicating a LOW condition)
    28 input (voltage changes to 0.20 indicating an INPUT condition)
    28 output 28 high (voltage drops to near zero, indicating a HIGH condition)

    Pin 28 works fine and confirms pfth Forth is working right.

    But the same tests on Pin 29 will not toggle between HIGH and LOW in OUTPUT mode.
    Pin 29 still toggles between OUTPUT and INPUT modes, so it may be that only the High/Low OUTPUT function is damaged.

    It seems I may have damaged the i/o on Pin 29. Testing Pins 26 and 27 work the same as Pin 28.

    It is a bit disappointing to have possibly damaged an i/o pin so soon after purchase of the BeMicroCV, but these things do indeed happen. And I can reassign Pin29 to work around the problem. I can also review the code to make sure Pin29 is assigned correctly, but there is more likelihood that I overloaded the pin and it is never coming back.

    I guess you can at least see why I like Forth. I can do quick diagnostics in an interactive mode. And even with the damage to the Pin29 i/o, the BeMicroCV can and will offer hundreds of hours of use. I can still get the EEPROM working through a Pin reassign and rebuilding the tiny daughter board. And if that works I can follow up with changing the on-board SMD EEPROM.

    Further more, I purchased a BeMicroCVA9 that remains in the box until I learn to be more careful.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2015-08-16 12:08
    I guess this is a Forrest Gump moment -- when you get lemons, make lemonade.

    Before I jump into rewiring the DIY daughter board, I am going to try to run Diagnostics and a Reload in Quartus II.

    Just maybe..... Altera might have provided the means to work around damage within the Cyclone V E.

    Or maybe not.

    But it certain is something useful to explore as I still have a PIN 29 connection that toggles between INPUT and OUTPUT. There is a connection to the pin and it can handled 3.3VDC. It is just not complete.
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