FriendlyELEC-Forum

Hello all,

I am designing a custom camera module for the Air board. And I've got a question about I2C voltage levels.
I did not find any schematics of the CAM500B module and I am a bit confused with it. As the OV5640 datasheet says Vdd-io (digital I\O) is in the range from 1.71 to 3.0 V with typical 1.8. At the same time the schematics of the Air board shows that all VCC_IO pins are connected to the VDD_SYS_3.3V. I cannot find any mentioning in the H3 datasheet about the voltage levels of the TWI2 interface.

Is there a voltage level translator ic on the CAM500B module?

Hm. I have found http://wiki.friendlyarm.com/wiki/images ... ematic.pdf
And here http://www.friendlyarm.com/index.php?ro ... uct_id=155 it is said that the CAM500A is easily converted to the CAM500B by modifying the VDDIO voltage. But the value of the VDDIO for the CAM500B is a bit strange - only 3 volts.
Also I have found that the OLIMEX board with the H3 has unpopulated pullups for the I2C to 3.3V and at the same time some versions of OrangePi have pullups to 2.8V.

So who's right?