Another person with an problem programming the Attiny 85

Hello all,

Has anyone seen this issue before? I setup my Uno to load sketches to the 85 and all seems to go well. I get the standard ""
avrdude: please define PAGEL and BS2 signals in the configuration file for part ATtiny85
avrdude: please define PAGEL and BS2 signals in the configuration file for part ATtiny85

from which I understand is normal. But when I try to run the simple blink sketch on any chip, it is like it is running in slow motion. The normal 1 second blink, takes about 8 seconds. I have tried everything I can think of. I have even switch the output pins to see if it is actually taking the code, and it does.

Any thoughts?

Thank you

A small update. I changed the delay to the 85 and set it to 10 ms. It flashes at the same rate as the Arduino set at 100 ms. So with the naked eye and trying to judge it, the 85 flashes roughly 8 to 10 times slower than the Arduino...So confused.


So I think I figured it out. Figures wait three days to post in the forums and then discover the issue. It appears I was programming the chip as the Attiny 85 *MHZ" clock when I should have set it to the 1 MHZ clock. Hopefully this will help others...

By default the chips come with a 'divide internal oscillator by 8' fuse bit set which means that the CPU is running at 1MHz.
If you want it to run at 8MHz, you need to select the 8MHz part from the list of boards, and then click 'Burn Bootloader'. While this doesn't actually download anything, it does set the fuse bytes to allow the chip to run at 8MHz (you only have to do this once).


Thank you so much. I have been trying to figure this out for 3 days. As you suggested, I selected the Attiny85 @ 8MHZ and selected burn boot loader. I then uploaded a sketch that was designed to run at the frequency and BOOM.

Thank you so much.

This method should work exactly the same for the Attiny 84, correct? I selected the appropriate chip and tried the same thing with the 84 but it is having a similar result of the 85 at 1 mhz. It seems to take simple sketches like blink and fade easily but does not want to run a more complicated sketch. Very interesting. Some more toying around is in order.

Yup, same processes. You just need to set the fuses once for each chip which is what the burn bootloader bit does.