hi quick question, can i run on a breadboard atmega328p w/ ext 16Mhz at 3.3v? with the uno board file loaded?
Yes.
Hi,
Crossroads is probably the expert on this. I believe the 328 spec. says voltage should be higher at 16 Mhz, but I have run a number of samples of our Robo1 board with the onboard 3.3V option for a couple of days without problems..
YMMV
DISCLAIMER: Mentioned stuff from my own shop...
thank you very much gents 
cool board!
terryking228:
I believe the 328 spec. says voltage should be higher at 16 Mhz, but I have run a number of samples of our Robo1 board with the onboard 3.3V option for a couple of days without problems..
The spec says it will need about 3.8V @ 16MHz but it will probably run fine in at lower voltages in many cases.
The number in the datasheet is most likely based on what's needed to guarantee that all functions will work reliably over time in some worst case scenario.
When you work outside specification you may loose precision or stability but you can also be just fine depending on the circustances.
Only way to find out is by testing.
"but it will probably run fine in at lower voltages in many cases"
Full performance is not guaranteed, so odd things may happen, as perhof points out, may be especially noticable over wider temperature range.
ok thanks guys, ill keep that in mind. i however did get an 8mhz ext crystal board file from someone here on the forums so ive been using that, but im gonna experiment with 16Mhz @ 3.3, i will keep in mind all your advice.
You may want to check the difference between mHz and MHz, lest you be disappointed with your device's performance.
AWOL:
You may want to check the difference between mHz and MHz, lest you be disappointed with your device's performance.
sorry bout that, i did not know. thx for the heads up.