Anyone searching for a way to connect multiple rotary encoders on the I2C bus, may be interested in a new piece of hardware created by Simone based in Turin, Italy. The aptly named I2C Encoder V2 ...

Adafruit has made an I2C interface for four rotary encoders. It comes in the form of a PCB with four footprints that accept one of the most common rotary encoder forms (Bournes PEC11 horizontal style) ...

[Igor] has an AS5600 magnetic rotary encoder chip on a breakout board. Normally, you’d think that was an easy device to work with since it has an I2C interface. But [Igor] wanted to do it the hard way ...

Figure 1 shows a typical converter schematic. The I2C bus is connected to PIN5 and PIN6, and the SPI bus is connected to PIN9, PIN10, PIN11, and PIN12. PIN8 is used to control the transmission ...