Can 3.3v arduino comunicate to 5V arduino?

Hi. i`m planning to connect 2 arduino minis. On one end i need 3.3v 8mhz version to avoid level shifter for the display, On the second end i think i need 5V 16mhz version (~4meters away) i need 5V option as i have 5x pressure sensors with range 0.5v-4.5v.(unless i can supply 5V signal to 3.3v arduino version)

Is it possible to get them talking together?? I2C will work??

thanks in advance


Read this article it might give answers for your question.

click here

Best regards.

if i get it right, it can work, but in the safe manner i rather use 2x 5v arduinos plus level shifter for the screen. this way it should work without problem. any real life experience with usb cable longer than 5m and i2c protocol??

If you understand circuitry, this is 3.3V RPi connections to 5V. RPi GPIO Interface Circuits

The bottom 1/3rd shows 3 different voltage leveler circuits.

The 7407 chip can support 6 circuits shown.

Learn these, keep some parts and when you need to connect yet another 3.3V to 5V it will not be a problem with shipping time connected.

I have had problems extending I2C beyond 10cm. The capacitor coupling between the SDA and SCL was a problem.

I have successfully used SPI at more than 10ft (3m) but I don’t expect it to be reliable.

The 5v analog pressure sensors are very very easy to interface to a 3.3v Arduino. Just put a voltage divider (2 resistors) on each one.

MorganS, i already used SPI for the screen. Regarding the sensors, as i have 5 of them than CD4050 will work as well?? Looks like i have to work something out in regards I2C and the distances.

MorganS: I have successfully used SPI at more than 10ft (3m) but I don't expect it to be reliable.

What speed? I see dividers used for half and quarter speed in SD test code examples. I had this idea that SPI should be like 20 cm or less short!