What is it?

The I2C Extender is a cable length extender for I2C communication, using the P82B715D from Texas Instruments. It allows I2C devices to be located up to 50m apart and connected using twisted pair cable (or a suitable equivalent). Put one of these in between an I2C device and the cable, so a minimum of 2 Extenders are needed to allow the comms over the long cable length.

Features

• Single supply operation.
• Friction lock XH connectors.
• On LED indicator.
• Drive cable with up to 3000pF on the transmission cable, and 400pF on the main host/device I2C bus.
• Allows multi-drop distribution of I2C signals using easily available twisted-pair cable.
• 37mm x 28mm board size.
• 2 x layer with 1oz copper.

Why did you make it?

I made this to help me when connecting multiple I2C modules to a processor module (like Arduino and STM32 boards), and the wire length between them was very long (10m+). This helps to I2C reduce communication errors, and allow more reliable reading of the remote I2C sensors.