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arduino to PC serial port problems
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arduino to PC serial port problems

by fogdrop on Tue Feb 24, 2009 5:07 pm

I've just started playing around with a Diecimila I bought a while ago. I've been able to run simple examples with no trouble. I added some some simple Serial.print statements to the Blink program and displayed them using the serial port monitor.

Then I broke out a serial cable and plugged Tx into pin 0, Rx into pin 1 and Signal Ground into one of the Diecimila ground connections. I connect this to another computer and run a terminal program, set the baud rate to match the Serial.begin statement and power up the Arduino.

All I see is garbage, like the baud rate is set wrong.

I've tried all sorts of permutations, different baud rates, character make-up, etc. Verified the cable by connecting to another PC, etc. I also tried using the SoftwareSerial library and different pins. I'm an old hand at serial comms but this has stumped me for more than a day.

Am I incorrect in thinking Signal Ground should connect to the Diecimila ground ? Is there some other trick I have missed?

thanks in advance for your help.

fogdrop
 
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Re: arduino to PC serial port problems

by mtbf0 on Tue Feb 24, 2009 11:34 pm

fogdrop wrote:\Then I broke out a serial cable and plugged Tx into pin 0, Rx into pin 1 and Signal Ground into one of the Diecimila ground connections. I connect this to another computer and run a terminal program, set the baud rate to match the Serial.begin statement and power up the Arduino.

All I see is garbage, like the baud rate is set wrong.
your arduino may well be garbage by now. it's not compatible with the voltages a serial port outputs.

hope i have misunderstood your problem.
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Re: arduino to PC serial port problems

by fogdrop on Thu Feb 26, 2009 11:29 pm

mtbf0 wrote:your arduino may well be garbage by now. it's not compatible with the voltages a serial port outputs.

hope i have misunderstood your problem.


Thanks for your reply, you got it right. But I'm a lucky guy, the arduino seems to be OK. It inputs and outputs low and high on all pins.
Going forward, I'll have to make sure to engage the part of my brain that has my rudimentary electronic knowledge.

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