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dritcey / optiboot

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Arduino Pro 8Mhz doesn't work at 115200bps #58

Open GoogleCodeExporter opened 8 years ago

GoogleCodeExporter commented 8 years ago 
The makefile for the Arduino Pro 8MHz board specifies 115200bps for the upload 
speed, but in fact this bit rate is unlikely to work.  (8+% error and a very 
tiny divisor.)

tests have shown that it works OK at 57600bps.

Original issue reported on code.google.com by wes...@gmail.com on 10 Feb 2012 at 7:09

GoogleCodeExporter commented 8 years ago 
Actually, all four 8MHz clocked platforms in the Makefile have 115200bps 
(lilypad, lilypad_resonator, pro_8MHz and atmega328_pro_8MHz.

Original comment by xyzz...@gmail.com on 10 Feb 2012 at 1:23

GoogleCodeExporter commented 8 years ago 
(actually, in the U2X mode used by optiboot, it ought not be "too bad."  Needs 
further research.)

Original comment by wes...@gmail.com on 17 Mar 2012 at 3:51

GoogleCodeExporter commented 8 years ago 
According to http://appnote.avrportal.com/calculator/avr-usart-baud-rate, at 
8MHz using U2X mode, 115200bps will be -3.55% off.  Unfortunately, on Uno-style 
boards with another AVR (@16MHz) doing the USB/Serial conversion, THAT uart 
will be 2.12% off (ie in the OTHER direction, for a total error of 5.67%

Original comment by wes...@gmail.com on 31 Mar 2012 at 3:58