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Author Topic: Need a new update for the 115200 baud Problem  (Read 895 times)
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Hello together,

i have here two arduino uno R3, an arduino duemilanove and a arduino nano V3.0.
The uno has a atmel rs232 bridge, the nano and the duemilanove a FTDI chip.
The UNO R3 works 100% save with serial communication and 115200 Baud.
The Nano seems to have problems with my 4 byte transfere from the computer to the arduino (only once 4 bytes).
If I program the nano the communication works if I do not disconnect the usb line after the programming. If I do a disconnect and reconnect the arduino do not understand the 4 bytes again. Also setting the DTR and CTS hardware lines change the communication in data loss.

The web says now two things:
a.) buffer problem, the 328 can only take one (some tell three) bytes and the interrupt cannot be fast enough
b.) the 16MHz timing does not fit to 115200 Baud, but mostly with above 115200 baud (I need uncommon baudrate)

Why the UNO R3 is working pefect? Why do the nano serial work better if I program it before I use it?
Why the interrupt is blocked, some tell me there has been done optimations in the library. (I use latest arduino IDE)
I can use uncommon baudrates but which unknown baudrate is known as good for 115200?

Last but not least I am searchin for save libraries.

Would be fine if someone can explain this different problems with the same atmel chip.

http://arduino.cc/forum/index.php/topic,98364.0.html
http://binglongx.wordpress.com/2011/10/26/arduino-serial-port-communication/
« Last Edit: February 13, 2013, 07:06:54 am by sirnoname » Logged

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Noone do have this problem?
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I have used my arduino even at 500.000 baud (to communicate to a PC)

Can you post both sketches you use at both sides?
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Rob Tillaart

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Which arduino do you talk about?
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both duemillanove and uno
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Rob Tillaart

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