Is it possible to power an atmega328p @ 8mhz with cellphone charger?
It provides 6.21VDC, is it too much for the mcu? If so, how can I drop it down to an acceptable value?
I put 4 diodes in series and got 5v (each diode drops 0.3v), is there anything simpler?
I put 4 diodes in series and got 5v (each diode drops 0.3v), is there anything simpler?
What's going to happen when the battery gets depleted? There is a reason why all Arduinos use a voltage regulator.
Only need something like 2.5V for 8 MHz operation, so the battery can get pretty low.
Even 2 diodes so the voltage is closer to 5.5V would be okay as a starting voltage.
Sorry if I wasn't clear, but there's no battery here. I'm just using an old cellphone charger as a wall power supply for an standalone arduino project
So, it's fine 5.5v?
Yes, 5.5v should be fine.
• Operating Voltage:
– 1.8 - 5.5V for ATmega48PA/88PA/168PA/328P • Temperature Range:
– -40°C to 85°C
• Speed Grade:
– 0-20MHz@1.8-5.5V
*Above info taken from ATMega328 Datasheet @ http://www.mouser.com/ds/2/34/doc8161-38269.pdf
I don't know if anything would be "simpler" than your diode setup....but a voltage regulator might be a "better" option if you're going to use that power supply. I have a dozen or so USB/iPhone chargers laying around; I typically use them for this sort of purpose. They output a VERY controlled 5.0v & between 0.5 - 1.5 amps, depending on which brand/version I use.
Good luck! Let us know how it works out.