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Topic: Arduino to breadboard - 3.3V power supply? (Read 553 times) previous topic - next topic

d82k

Hello,
Looking on the internet I was not able to find answer to this...
I have followed this tutorial to have a standalone arduino on breadboard: http://arduino.cc/en/Main/Standalone.
Currently I use, as power supply, my Arduino UNO connecting directly the 5V and GND to the breadboard + and - (ignoring the 5V regulator on the tutorial).

I'm wondering if I can power supply the breadboard using 3.3V instead. Are there any side effects, or it is going to work?
I think that doing this also the serial connection and outputs will work at 3.3V, is it correct? Can I than connect it to another device with 3.3V serial interface?

Thank you,
dk

Osgeld

there is a voltage vs speed chart in the datasheet, in a nutshell at 3.3v the best option for using arduino means cutting the clock back to 8Mhz
http://arduino.cc/forum/index.php?action=unread;boards=2,3,4,5,67,6,7,8,9,10,11,66,12,13,15,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,86,87,89,1;ALL

MarkT

If the Arduino is at 5V and breadboard at 3.3 you probably will need level shifters for the signals - 3.3V devices wont tolerate 5V and no device should have a logic input outside its supply range.

The ATmega chips will usually work at 16MHz at 3.3V at 25C, but you have no guarantee
[ I won't respond to messages, use the forum please ]

fungus


I'm wondering if I can power supply the breadboard using 3.3V instead. Are there any side effects, or it is going to work?
I think that doing this also the serial connection and outputs will work at 3.3V, is it correct? Can I than connect it to another device with 3.3V serial interface?


It will work, but not at 16MHz. The datasheet has a graph of maximum clock speed vs. voltage.

No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

d82k

Thank you all for your answers.

I have read a bit on the internet, and, if I have well understood, I can use the seme circuit of the tutorial just substituting the crystal 16mhz with one at 8 and the circuit should be good. Any other change to the capacitor or other components is needed?

Than I should change the bootloader using the one "Arduino Pro or Pro Mini (3.3V 8MHz) with atmega328" and my arduino on the breadboard should work at 3.3v right?

Thank you,
dk

fungus


Thank you all for your answers.

I have read a bit on the internet, and, if I have well understood, I can use the seme circuit of the tutorial just substituting the crystal 16mhz with one at 8 and the circuit should be good. Any other change to the capacitor or other components is needed?

Than I should change the bootloader using the one "Arduino Pro or Pro Mini (3.3V 8MHz) with atmega328" and my arduino on the breadboard should work at 3.3v right?


Right.
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

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