Seeeduino v1.1 Output Levels

I’m wondering about the output levels on the Seeeduino v1.1. If I am powering the board with 3.3V will the output (and input) levels be 3.3V compatible or 5V?

I am looking to interface with a board over SPI (Raspberry Pi) that is strictly 3.3V logic levels and want to know if I need a level converter cricuit or if I can just wire them directly together.


Hi there,

Seeeduino V1.1? Not mega?
Can you attach the link?
Because I need more detail to make sure which seeeduino V1.1 is.

Best regards,


Unfortunately I can not be be certain that any of the links to current products are correct. Here is a picture of the board:

It is labeled as follows:

v1.1 09/23/2008
by Albert.Miao

The processor is an ATMEGA168

Dear customer,

If you switch to 3.3V then you can compatible to use with 3.3v device.
And also with the SPI interface.

Best regards,


Thanks so much for the information!

One more question:

When switching to the 3.3V setting on the board, will the supply voltage automatically be converted to 3.3V or do I have to use a 3.3V supply?

Automatically, so even you use 5V to supply with USB, when you switch to 3.3v then it would be out put in 3.3V. :slight_smile: