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Topic: Need help with ULN2803A (Read 983 times) previous topic - next topic

VirtualRob

Hi,
  I recently purchased the Arduino board and a ULN2803A IC Chip.  I'm new at this, and was trying the Stepper Motor example http://www.arduino.cc/en/Tutorial/StepperUnipolar.  I don't have the motor yet, but thought I would test it out by using some LED's, figuring I would see them turn on and off as it stepped through the positions.

Basically, the LED's are always on, and I'll see some dim while others go bright.  I wasn't expecting them always be on with a change in brightness.

I'm wondering if I'm missing some resistors or something, but I thought the ULN2803A would do it for me.  Is this something I would need to worry about once I get the motor?

Any help would be appreciated.

Thanks,
Rob

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