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SX28 Proto board — Parallax Forums

SX28 Proto board

Jason-WIJason-WI Posts: 35
edited 2007-09-26 21:15 in General Discussion
For some reason I have to press the reset button on the SX28 Proto board in order for my circuit to run. I am using a 4MHz ceramic resonator populated in the X2 slot. I built the exact same circuit on 2 proto boards and they both do the same thing. Is there something wrong with my configuraton of the SX when I program them?

Jason

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Comments

  • JonnyMacJonnyMac Posts: 9,216
    edited 2007-09-16 20:05
    Posting your program would be helpful.
  • Jason-WIJason-WI Posts: 35
    edited 2007-09-16 22:39
    Here is the program. I have tried different OSC settings without luck.may try a 4 MHz crystal osc with 22pF caps.



    Jason

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    He who dies with the most toys wins!
    SXB
    SXB
    Slacker_Alarm.SXB
    5K
  • BeanBean Posts: 8,129
    edited 2007-09-16 23:27
    Jason,
    Try added a brown-out option to the DEVICE line. Either BOR42 or BOR26.

    Bean.

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  • Jason-WIJason-WI Posts: 35
    edited 2007-09-17 01:07
    Bean,

    I tried both and neither worked. I am going to add a .1 uF cap from /MCLR to GND. This will pull /MCLR to GND until the cap is charged by the 10k resistor. These are 4MHz resonators that I bought from Parallax - just wanted to add that.

    Jason

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    He who dies with the most toys wins!
  • Jason-WIJason-WI Posts: 35
    edited 2007-09-26 20:33
    I believe that the I have a bad SX28 on this protoboard. I tried everything from a crystal to different frequency resonators and nothing works - I still have to press the reset button for it to startup. It only happens on one board now for some reason. I will order some extra smt·SX28's when I need more protobaords to have some spares on hand.

    I ended up adding a reset button to the enclosure for this one prototype.

    Jason

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    He who dies with the most toys wins!
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2007-09-26 21:15
    Hello Jason,

    You should only need a 4.7K or 10K pull-up on the /MCLR line. Perhaps there is a cold solder joint on your resistor so that it is really open instead of pulling that line high. If it is floating that would cause problems.

    Is the RTCC line disconnected? I usually tie it to ground if it isn't needed.

    Just a couple things to check.
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