pico-cec: HDMI CEC to USB keyboard adapter

Motivation

Micro/mini desktops are plentiful as second hand, budget friendly media players, especially when installed with Kodi (eg. LibreELEC). However, many of these devices do not support HDMI-CEC and require the user to use additional peripherals (eg. wireless keyboard, game controller).

In this project we use a Raspberry Pi Pico to both:

• handle the CEC protocol on the HDMI port
• adapt the user control messages into USB keyboard inputs

What Works

• HDMI CEC frame send and receive
• EDID parsing to determine HDMI physical address
• LibreELEC recognises Pico-CEC as an USB HID keyboard
• HDMI CEC basic user control messages are properly mapped to Kodi shortcuts, including but not limited to basic navigation and selection controls

How to Use

• Wire it up
• Upload the firmware
• Connect a USB cable from the Pico to the PC
• Connect the HDMI male port to the PC HDMI output
• Connect an HDMI cable from pico-cec to the display (eg. TV)
• Enjoy using TV remote