search

Optiboot / optiboot

Small and Fast Bootloader for Arduino and other Atmel AVR chips
Other
1.09k stars 401 forks source link

How up to USART 2M ? #286

Closed selevo closed 4 years ago

selevo commented 4 years ago

Error 0% for 16MHz

WestfW commented 4 years ago

"make xxxxx BAUD_RATE=2000000" ? I don't know if it works at that rate (you'd have fewer than 80 instructions per character to process it), but the MCUDude cores have pre-built bootloaders for up to 1Mbps. IIRC, people who have tried it have found 2Mbps not to be any faster than 1Mbps, overall. Actual flash write time becomes the dominating factor (~4ms per 128byte page on a m328p - about 320kbps.)

Or perhaps I didn't understand the question?

selevo commented 4 years ago

Thank you, everyone understood correctly. I somehow did not think about flash memory speed. So you can raise the speed in two? (BAUD 230400) UNO atmega328p 16MHz

WestfW commented 4 years ago

Can your host do 256000bps? That would be zero-error. 230400 has a 3.5% error, which is not good... Users have reported apparently increased performance running up to 1Mbps. 2Mbps (the absolute max that the chip is capable of) does not seem worthwhile.