- Tue Feb 28, 2006 1:18 pm
#10466
Okay, this may seem obvious to anyone who's done electronics, but I figured it's better to ask a stupid question than to save face and fry my board.
I just purchased the atmega128 header board from Sparkfun (looks sweet!), and was thinking of hooking it up and starting to learn...
1) Can I hook this up to a 9-volt battery? The datasheet for the on-board regulator (LM78L05) says there's a minimum voltage of 6.8, so I am assuming this is alright. Am I wrong to assume this?
2) Someone (I think it was Kuroi) recently introduced me to the concept of "ground loops" (where the "ground" value in one area of the circuit is not the same as in another area, causing current where you don't expect it). Again, talking down my paranoia, can I plug the negative (minus) terminal of the 9V directly into the ground line on my board? Is this the same "ground" as the ground pins on the atmega128, or will I fry something?
3) Are the 9V battery terminals really +9V and GND? Or are they something else (like +4.5V and -4.5V or something).
Sorry for the dumb questions, but I'm still learning...
thanks!
I just purchased the atmega128 header board from Sparkfun (looks sweet!), and was thinking of hooking it up and starting to learn...
1) Can I hook this up to a 9-volt battery? The datasheet for the on-board regulator (LM78L05) says there's a minimum voltage of 6.8, so I am assuming this is alright. Am I wrong to assume this?
2) Someone (I think it was Kuroi) recently introduced me to the concept of "ground loops" (where the "ground" value in one area of the circuit is not the same as in another area, causing current where you don't expect it). Again, talking down my paranoia, can I plug the negative (minus) terminal of the 9V directly into the ground line on my board? Is this the same "ground" as the ground pins on the atmega128, or will I fry something?
3) Are the 9V battery terminals really +9V and GND? Or are they something else (like +4.5V and -4.5V or something).
Sorry for the dumb questions, but I'm still learning...
thanks!