Pages: [1]   Go Down
Author Topic: Arduino to breadboard - 3.3V power supply?  (Read 523 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 30
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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
Logged

SE USA
Offline Offline
Faraday Member
**
Karma: 41
Posts: 3783
@ssh0le
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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
Logged


0
Offline Offline
Shannon Member
****
Karma: 206
Posts: 12169
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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
Logged

[ I won't respond to messages, use the forum please ]

Valencia, Spain
Offline Offline
Faraday Member
**
Karma: 146
Posts: 5494
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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.

Logged

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

Offline Offline
Newbie
*
Karma: 0
Posts: 30
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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
Logged

Valencia, Spain
Offline Offline
Faraday Member
**
Karma: 146
Posts: 5494
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

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.
Logged

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

Pages: [1]   Go Up
Jump to: