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Topic: Baudrate mismatch between board and serial monitor (Read 535 times) previous topic - next topic

amundsen

Hello,

I have an Arduino Pro Mini connected to a Mac computer over a FTDI to USB converter. I set my program to send data to the serial port at a rate of 9600 kbps. However I need to set the serial monitor to 4800 kbps to get a correct display (Arduino 1.05).

What's wrong ?

Thank you in advance.

robtillaart

9600 kbps or 9600 bps?

if you use 1.0.4 or another serial terminal app, does it show the same factor?

Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)

CrossRoads

Is that  3.3/8MHz Promini? That with a 16 MHz bootloader would have that effect.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

amundsen

Sure, it's bps, not kbps.

The board is a Watterott clone, Wattuino 5V/16 MHz with 328 and I choose the correspondant Pro/Pro Mini setting in the software.

The mismatch happens also with Arduino 1.04.

CrossRoads

Your description sounds like you got the 8MHz promini and not the 16 MHz promini.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

amundsen

Is there any way to test the board to check it doubtless ?

Nick Gammon

Looks like there is a box they tick on the back. Conceivably they got it wrong.

Can you see a frequency printed/stamped on the resonator?
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

amundsen

Nick, do you have any idea where the resonator is on the board and how it looks like ?

amundsen

The resonator is a silver component located besides the AVR. However it's so tiny I can't see the figures on top.

I had another suggestion: measuring the voltage between VCC output and GND. And indeed the board is a 3.3 version. But in between I have checked my orders and discovered I had indeed ordered 3.3V boards, not only 5V boards. I couldn't check visually because the board's bottom is covered with Velcro to tie the board to cloth. So I guess there's no error from the maker but from me only. Duh.  :smiley-red:

Nick Gammon

I think it's the silver thing directly above the RST pin.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

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