M5Stack : Mini Qwerty Keyboard CardKB, Grove

Mini I2C Keyboard for MicroControler project

Also known as "CardKB" this M5Stack unit implements full featured QWERTY keyboard.

With a keyboard, it is possible to consider typing and interaction with your software. This offers amazing possibilities.
This is quite a lot more buttons than the M5 Core unit which hold only 3 buttons.

The keyboard also have 3 combinations keys/buttons with Sym key for symbol, Shift key as regular keyboard and Fn key for function. So a single key like "a" letter can be used with Sym+Key, Shift+Key, Fn+Key. Rich set of possibilities.

This unit communicates with M5Core via an I2C interface (see the GROVE A port) on address 0x5F.

What are the possible combination:

• Single button pressed: the keyboard will output the lower case key. Pressing the "Q" on the keyboard will output the lower case "q". For the special key like "tab" (tabulation) or "Esc" (escape), this will send the corresponding code (aka control code).
• Shift+key: the keyboard will output the upper case form of the letter. Pressing Shift+"Z" on the keyboard will output a capital "Z".
• Sym+key: the keyboard will output the second value of the key drawed on the top-right position of the key's letter. Pressing Sym+"2" will output the "@" key.
• Fn+key: the function key is used to access the third key value available on some of the keys.
  The value outputs by this function key can be used to create unique keyboard features (like a Ctrl+C combination to halt a MicroPython script).