m5::unit::UnitCardKB2 Class Reference

Card-size 42 key QWERTY keyboard — I2C mode (SKU:U215) More...

#include <unit_CardKB2.hpp>

Inheritance diagram for m5::unit::UnitCardKB2:

Classes
struct	config_t
	Settings for begin. More...

Public Member Functions
	UnitCardKB2 (const uint8_t addr=DEFAULT_ADDRESS)
virtual bool	begin () override
virtual void	update (const bool force=false) override
virtual char	getchar () const override
	Gets the character if input.
uint8_t	available () const
	Number of available characters (0 or 1)
void	discard ()
	Discard current character.
Settings for begin
config_t	config ()
	Gets the configuration.
void	config (const config_t &cfg)
	Set the configuration.
Firmware
uint8_t	firmwareVersion () const
	Gets the firmware version.
bool	readFirmwareVersion (uint8_t &ver)
	Read the firmware version.
Public Member Functions inherited from m5::unit::UnitKeyboard
	UnitKeyboard (const uint8_t addr=DEFAULT_ADDRESS)
virtual uint8_t	released () const
	Gets the released key character code if updated.

Protected Attributes
config_t	_cfg {}
uint8_t	_pressed_key {}
uint8_t	_firmware_version {}

Detailed Description

Card-size 42 key QWERTY keyboard — I2C mode (SKU:U215)

CardKB2 supports I2C and UART communication via GROVE port, selectable on the device:

• Fn+Sym+1: I2C mode (factory default) — returns ASCII per keypress
• Fn+Sym+2: UART mode (115200-8N1) — use UnitCardKB2UART for this mode

The selected mode is saved and persists across power cycles.

In I2C mode, the firmware returns ASCII on key press (not release) and auto-repeats after 300ms hold at 50ms intervals. Use getchar() after updated() to retrieve the pressed character.

Note

Sym key operates as a toggle (press once to activate, press again to deactivate). Blue LED indicates Sym mode is active.

Fn+D/Z/X/C arrow keys are not available in I2C/UART mode.

Unlike CardKB/FacesQWERTY, CardKB2 does not support software mode switching via readMode()/writeMode().

Warning

After switching communication mode (Fn+Sym+1/2), press the RST button on CardKB2 to reset modifier state. This will be fixed in a future firmware update.

Member Function Documentation

available()

uint8_t m5::unit::UnitCardKB2::available ( ) const

inline

Number of available characters (0 or 1)

Note

Provided for API compatibility with UnitKeyboardBitwise (UnitCardKB2UART)

begin()

bool m5::unit::UnitCardKB2::begin ( )

overridevirtual

Reimplemented from m5::unit::UnitKeyboard.

discard()

void m5::unit::UnitCardKB2::discard ( )

inline

Discard current character.

Note

Provided for API compatibility with UnitKeyboardBitwise (UnitCardKB2UART)

firmwareVersion()

uint8_t m5::unit::UnitCardKB2::firmwareVersion ( ) const

inline

Gets the firmware version.

Return values

Firmware

version read during begin()

Warning

Valid after begin

getchar()

virtual char m5::unit::UnitCardKB2::getchar ( ) const

inlineoverridevirtual

Gets the character if input.

Return values

!=	0 Pressed character
==	0 Not input or invalid character

Note

CardKB2 I2C firmware sends ASCII on key press (not release)

Reimplemented from m5::unit::UnitKeyboard.

readFirmwareVersion()

bool m5::unit::UnitCardKB2::readFirmwareVersion

(

uint8_t &

ver

)

Read the firmware version.

Parameters

[out]

ver

Version

Returns

True if successful

update()

void m5::unit::UnitCardKB2::update ( const bool force = false )

overridevirtual

Reimplemented from m5::unit::UnitKeyboard.