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Author Topic: Mini Pro Serial port running at half speed  (Read 675 times)
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Ashburn, VA, USA
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So this is odd...
I pulled two Arduino Mini Pro's (3.3V - 8kHz) out of my bin to use them and I was having difficulty even getting a "Hello World" sketch to work properly on either. I put the same sketch on an Uno and it worked fine. After noodling around it was clear that I have to set the serial monitor on my laptop to twice the baud rate as I specify in the sketch. When I do that it works fine. I'm guessing the problem is either that the serial port on both mini's is running at the wrong rate or the Arduino ide (mac) is mismatched for the mini.

I put the mini on a logic analyzer and and it confirmed that the data is coming out at 14400 even though I initialized the serial port at 28800 so I guess it's something in the mini.

Any ideas?
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I don't think you connected the grounds, Dave.
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(3.3V - 8kHz)
Eight what?
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Ashburn, VA, USA
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Ooops, 8 MHz...

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Any ideas?
probably the signature of the Arduino in the source code of the serial port is missing the particular type.

You can check the clock freq.
Code:
void setup()
{
  Serial.begin(14400);
  Serial.print("FREQ CPU: ");
  Serial.println(F_CPU);
}

void loop(){}
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Rob Tillaart

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