Hey guys, got a quick noob question.
I'm powering a standalone 328p-pu chip at 16mhz with 3 AA batteries, so 4.5v. Is it bad for the 328p-pu to just let the batts run dead? Though I read that running it at 3.3v and 16mhz was overclocking it and that wasn't good.
thanks
Jason
Not bad for the Arduino. AA alkaline, toss when drained. AA-size & rechargeable, probably don't want to let them get totally dead or they may not take a charge again.
16 MHz is within spec down to ~3.78V (can do the math on the speed grade chart in the datasheet, section 29.3 in the Atmega328 Feb 2013 datasheet).
Below 3.78V, you're overclocking for the voltage and some things might appear to get flaky, or stop working.
Where it's seen on some devices is that the serial port stops working correctly.
Writes to EEPROM might get corrupted.
The chip might shut down if the voltage goes below the Brown Out Voltage, depends on how those fuses are set.
Won't cause any permanent damage tho.
If you are controlling something important, things may not function as you expect. Things may go very bad if the controlling sequence is wrong.
As implied setting the fuses for the Brown Out Voltage might be something to looked into, however, I am not sure how this is done. Crossroads might know.
Thanks for the info guys, appreciate it.
Jason
The slower you can run the target, the more run-time you will get out of the batteries. (I have an ATtiny84 sitting on my desk that has been running non-stop (no sleeping) on two AA batteries for several weeks. It's clocked at 128kHz which is perfect for the application.)
Does the target need to be running at 16 MHz? Have you determined your application needs that much processing?