I've search all over to no success. I tried the data sheet, but couldn't make heads or tails of it. What is the voltage of an output pin of the ATtiny 85 when high? is it just the same as the input voltage a vcc? Also, what is the maximum current output when run at 3.3v?
This is from the datasheet
The output voltage depends on the current that you sink when the output is set to LOW state
Or the current you source when the output is set to HIGH state
Table 21.1, on page 161 of the ATTiny25/45/85 datasheet states that the output high voltage is 4.3 volts with a Vcc of 5 volts, and output current of 10 mA. For 3.3 Vcc, the voltage is 2.5 V at 5 mA. (both voltages are minimums)