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Author Topic: bootloading ATMEGA168A-PU using OptiLoader  (Read 876 times)
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i recently bootloaded an ATMEGA168A-PU and an ATMEGA8L-8PU using westfw's  optiloader
what is the difference between A-PU and P-PU??????
also what is the meaning of 8PU????i read somewhere that it meant that the max frequency is 8Mhz

i programmed the bootloader on the empty chips using my Arduino UNO R2

i used the exact circuit given here for both the chips

i did not find any errors while burning the bootloader
no errors seen on the serial monitor

also when i powerup the chips on a breadboard the LED on pin 13 blinks everytime i press reset.
does this mean that my bootloader is fine??

i am asking this because i am building my own arduino serial (for a school project) for which i used the ATMEGA168 and i am not able to upload any sketches! here is the link,103229.0.html

any help would be very much essential

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Which bootloader did you burn?

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Presumably the one OptiLoader installed for him.  I'm pretty sure that means 4.4 for the correct chip.

If you get three quick blinks when you hit reset, that should mean that the bootloader is installed and is basically working.

An 8L-8xx processor is supposed to be a "low power" version guaranteed to run 8MHz at a lower voltage than 5V.  The general suspicion is that they'll also run 16MHz at the full 5V, but that's not guaranteed.

An 8A-xxx is the newest version of the atmega8.  I believe that it's supposed to be identical, just using a newer semiconductor process.  8-xxx, 8L-xxx, and 8A-xxx all have the same "device signature", so they'll all be treated the same by optiloader and the Arduino IDE.  There was never an 8P-xxx (but on the newer chips, like the 88P, the "P" functionality subsumes the old "L" functionality - yyyP-xx chip will run (are SPECIFIED to run) at lower voltages and power than the old non-L chips.

Note that for a mega8 or mega168 with optiboot (as installed by optiloader), you WILL need to modify boards.txt and add "mega8 with optiboot" and "mega168 with optiboot" board types.  The existing 8/168 board types assume a different bootloader that runs at a different bit rate.

Code: with optiboot
opti8.bootloader.lock_bits=0x0F with optiboot

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thanks a ton westfw !!!!!!!!! smiley)))))
you are a genius!

i added "ATmega168 with optiboot" and it worked like a charm
was successfully able to upload and verify the blink sketch on my breadboard arduino serial

thanks all smiley)

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