Should I have to burn boot loader every time I upload a new sketch? I'm using the ATMEGA328P-PU Chip on a breadboard. Have the AVR MKII burner, Everything works fine except if I want to upload a second sketch the upload fails. If I burn the bootlader again the new sketch uploads. Is this normal? Am I using the wrong chip for this, or is my bearbones setup mising some circuitry for multiple uploads.
Is this normal?
No it is not, the bootloader should be protected by proper setting of the lock bits after burning of the bootloader the first time. Maybe if you show us the procedure you use someone can point out the missing step(s).
Lefty
This is the procedures I am following here http://itp.nyu.edu/physcomp/Tutorials/ArduinoBreadboard. The only difference is my OS is Ubuntu 10.10 and the Arduino program is version 21. I will post the error code this evening ( don't have access to it right now ), and I'll also try burning the boot loader on my duemilanove (with a new chip) directly to see if I get the same results.
Also, if the chip isn't resetting automatically, you might not be triggering the bootloader on upload. When you've just burned the bootloader and there's no other program on the chip, the bootloader runs over and over, so you can upload at any time. Once another sketch is on the chip, the bootloader is only active for the first second or two after you reset the chip.
Did some chip swapping to my duemilanove works fine, even though I burned the chip on the breadboard. The chip out of the duemilanove does not take a second upload on the bread board. Re built the circuit on a different bb with the same results, works fine for the first upload the second fails the 'programmer not responding'. The RX led never lights up on the second upload, though the TX does a few blinks.
Also tried pressing reset and immediately uploading with the same results.
Got it! The tutorial does not hook up the DTR. Guess I shold have figured that out, was that what you were trying to get across Mellis?