Hi
I want to understand can we burn bootloader and upload sketch to ATMega2560 16au with external 8Mhz crystal so that we can run atmega with 3V( with 8MHz we can run 2.7v to 5v mentioned in datasheet)
Or to use 8Mhz crystal i need to buy atmega2560 8au only??
As i can not run atmega2560 16au and 16mhz cryatal(external) with 3v.
Thanks in advance!!
Hi
I am planning to use low voltage Atmega2560 8au with 8Mhz crystal.
Will http://www.gammon.com.au/bootloader bootloader work with it also ?
hi
I have used Gammon bootloader for Atmega2560 16au with 16Mhz external crystal and its works like a wonder.
But in my new project I have 3V power supply so I am planning to use low external crystal so that I can operate the Atemga with low frequency and so the voltage will be go as low as possible.
My first question:
I uploaded the bootloader using 8Mhz external crystal and it went sucessfully but I am not able to upload sketch.
so here is my question : Can i ran Atmega2560 16au with 8Mhz crystal and will it work at 3V ,without any risk?
My second question:
As i do not having Atmega2560 8au right now so i am not able to test. will your bootloader works with Atmega2560 8au and external 8Mhz crystal. or before burning bootloader I need to make any changes.
Sorry to ask you such a long query . But I have really spent lots of time looking at this and finally today i post every where.
Please respond me.
Thanks a lot. I will wait for your response.
To run at 3V, you need a 2560V, instead of a 2560:
Speed Grade:
ATmega2560V/ATmega2561V:
• 0 - 2 MHz @ 1.8V - 5.5V, 0 - 8 MHz @ 2.7V - 5.5V
ATmega2560/ATmega2561:
• 0 - 16 MHz @ 4.5V - 5.5V
Yes, but you'll need a new boards.txt entry with 8mhz for fcpu and half the upload speed (since uart is derived from system clock and you're using a bootloader compiled for 16mhz - it's just as well though, I've had problems with 115200 at 8mhz)
Several topics by
ssomnath678
have been merged, all dealing with '2560 at 8 MHz & 3V.
'2560V is needed for 3V operation.