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Topic: Some basic question about AVR chips and Arduino (Read 2 times) previous topic - next topic

pylon

The optiboot (used on an UNO) is 1467 bytes (hardware/arduino/bootloaders/optiboot/optiboot_atmega328.hex). That's how you can know it.

Vincent19

I mean for the total available size for the sketch. When I burn bootloader, the chip memory would be reduced by approximate 2kb right ? But where can I see it ?

Arrch


How can I know that 2kb is used for the bootloader file ? I want to see for the difference when I upload bootloader and remove bootloader but I cant see it ><

See the difference in what? The size? Add 2K if you are using the bootloader to upload the sketch, don't if you are not.

Vincent19

I mean I want to see the difference in the size..LOL. Cause I want to experiment something..Heheh..

retrolefty


I mean I want to see the difference in the size..LOL. Cause I want to experiment something..Heheh..


Well you could always look at the maximum upload memory size defined for each entry in the arduino core file 'boards.txt'.

You can see that the Uno has a value of:
uno.upload.maximum_size=32256

While the Duemilanove has a value of:
atmega328.upload.maximum_size=30720

The difference is the size of the bootloader memory size protection options used to hold the two different bootloaders used by these too boards.

Lefty


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