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Arrgh! Prop Mini Wiring Messup — Parallax Forums

Arrgh! Prop Mini Wiring Messup

PropellerGuyPropellerGuy Posts: 33
edited 2015-03-10 20:33 in Propeller 1
I soldered up my Prop Mini, and plugged a Prop Plug in DIRECTLY. Only after failed communication attempts did I consult the datasheet and see that the serial com pins aren't actually in the correct order !!!

Did I completely ruin the chip?

And WHY did Parallax do such a thing?!

Comments

  • Bob Lawrence (VE1RLL)Bob Lawrence (VE1RLL) Posts: 1,720
    edited 2015-03-06 18:24
    re: Did I completely ruin the chip?

    Not necessarily. Just rewire it and try it.
  • xanaduxanadu Posts: 3,347
    edited 2015-03-06 18:25
    It is supposed to be plugged in directly, maybe you have it upside down (pins reversed)?
  • WBA ConsultingWBA Consulting Posts: 2,934
    edited 2015-03-06 23:28
    Should not be any permanent damage. I have done the same a couple times by accident as well even though the Prop Mini is labeled with VSS and RX.
    attachment.php?attachmentid=113414&d=1425713235
    PropMini--PropPlug.jpg
    910 x 273 - 225K
  • localrogerlocalroger Posts: 3,451
    edited 2015-03-07 07:58
    It's probably OK, like WBA I've done the same thing a few times. I think the logic is that if you use a right-angle header, pointing off the end of the mini, then the logo side of the PropPlug would be up as in WBA's picture. But if you use a straight-up header, intuition suggests the logo should face outward, but it actually needs to face toward the CPU to keep the pins right. I also have to be wary of this on projects like my Nixie clock where I replaced the right-angle header on a protoboard with straight up pins.
  • mmowenmmowen Posts: 38
    edited 2015-03-07 21:41
    Try applying two dots of DeccoColor opaque paint marker on the board surface adjacent to the programming header; red near the RX pin and blue next to the TX pin.

    It helps with visual identification of correct orientation.
  • PropellerGuyPropellerGuy Posts: 33
    edited 2015-03-08 18:57
    PHEWW, it's working all right now.

    While we're here, does anyone know if the HYDRA EEPROMs are significantly different from the one on the Prop Mini?

    Code which uses the EEPROM and works on the HYDRA is failing on the Mini, and YES I did remember to change the CLKMODE and XINFREQ.
  • WBA ConsultingWBA Consulting Posts: 2,934
    edited 2015-03-08 20:58
    The only difference is the size of the EEPROM, which is irrelevant since you are only working with the first 32k. Are you using the Hydra's onboard EEPROM or cartridge? (shouldn't make a difference, but details....)If you have CLKMODE and XINFREQ set for the PropMini correctly, my next suggestion is verifying pinouts and any associated pullups/downs. Are you using the same pins on both? Any other clues from your setup or program that you can share? picture, code, connection diagram, etc
  • PropellerGuyPropellerGuy Posts: 33
    edited 2015-03-10 20:33
    In the uOS v0.3.1 code, I used Nick Sabaulusky's EEPROM driver to access the area from $8000 to $10_000. The code ran fine on the HYDRA, but read incorrect data on the Mini.

    Curiously, the FSRW driver (the standard one) did not function correctly on the HYDRA, EXCEPT for the Exec() method.

    Very strange.
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