Using the 2nd I2C bus on the 2B v1.1 - Raspberry Pi Forums
*note*: applies pi 2b rev 1.1 since took me time figure out, , it's dead simple, i'd thought i'd post here it, save else hassle. first of; usage of 2nd i2c port adviced against, @ least 2 reasons: 1) can used eeproms (id_sd, id_sc) during boot 2) it's used camera module if don't use eeproms or camera, might fine. use @ own risk. me worked. open /boot/config.txt , add: code: select all dtparam=i2c_vc=on after this, 2nd i2c port available on pins 27 (sda) , 28 (scl) (fysical pins) or id_sd, idsc. measure, , because it's technically correct, 1 should add external pullup resistors. cheers! you need add pull-up resistors 3v3 on pins 27/28 them work i2c bus. raspberrypi