FT6236

This module provides a device-level API for FT6236-compatible capacitive touch controllers over I2C. More...

Collaboration diagram for FT6236:

Data Structures
struct	dev_ft6236_config_t
	Optional FT6236 initialization options. More...
struct	dev_ft6236_touch_t
	A single touch contact. More...

Macros
#define	DEV_FT6236_I2C_ADDR_DEFAULT   0x38u
	Fixed 7-bit I2C address - FT6236 has no address-select pin, so this is the only address it ever responds at. More...
#define	DEV_FT6236_MAX_POINTS   2u
	Maximum number of simultaneous touch contacts reported by FT6236.

Typedefs
typedef struct dev_ft6236_t	dev_ft6236_t
	Opaque FT6236 handle.

Enumerations
enum	dev_ft6236_touch_event_t { dev_ft6236_touch_up = 0, dev_ft6236_touch_down = 1, dev_ft6236_touch_move = 2 }
	Touch contact state reported by dev_ft6236_poll(). More...

Lifecycle
void	dev_ft6236_default_config (dev_ft6236_config_t *config)
	Fill an FT6236 config struct with safe defaults. More...
dev_ft6236_t *	dev_ft6236_init (hw_deviceio_t *device, hw_gpio_t *int_pin, const dev_ft6236_config_t *config)
	Initialize an FT6236-compatible touch controller over I2C. More...
void	dev_ft6236_deinit (dev_ft6236_t *ft6236)
	Deinitialize an FT6236 controller. More...

Properties
bool	dev_ft6236_irq_active (const dev_ft6236_t *ft6236)
	Report whether the FT6236 interrupt line is currently asserted. More...

Methods
bool	dev_ft6236_poll (dev_ft6236_t *ft6236, dev_ft6236_touch_t touches[DEV_FT6236_MAX_POINTS], uint8_t *out_touch_count)
	Poll the controller and parse the latest touch frame. More...

Detailed Description

This module provides a device-level API for FT6236-compatible capacitive touch controllers over I2C.

Macro Definition Documentation

DEV_FT6236_I2C_ADDR_DEFAULT

#define DEV_FT6236_I2C_ADDR_DEFAULT   0x38u

Fixed 7-bit I2C address - FT6236 has no address-select pin, so this is the only address it ever responds at.

For use with hw_i2c_init() / hw_i2c_init_default() when constructing the device handle passed to dev_ft6236_init().

Definition at line 33 of file ft6236.h.

Enumeration Type Documentation

dev_ft6236_touch_event_t

enum dev_ft6236_touch_event_t

Touch contact state reported by dev_ft6236_poll().

Enumerator
dev_ft6236_touch_up	Contact lifted - no longer touching.
dev_ft6236_touch_down	A new contact.
dev_ft6236_touch_move	An existing contact moved.

Definition at line 53 of file ft6236.h.

             {
  dev_ft6236_touch_up = 0,   
  dev_ft6236_touch_down = 1, 
  dev_ft6236_touch_move = 2, 
} dev_ft6236_touch_event_t;

Function Documentation

dev_ft6236_default_config()

void dev_ft6236_default_config

(

dev_ft6236_config_t *

config

)

Fill an FT6236 config struct with safe defaults.

Parameters

config

Config structure to initialize.

dev_ft6236_deinit()

void dev_ft6236_deinit

(

dev_ft6236_t *

ft6236

)

Deinitialize an FT6236 controller.

Parameters

ft6236

FT6236 handle.

Passing NULL is safe and is a no-op.

dev_ft6236_init()

dev_ft6236_t* dev_ft6236_init	(	hw_deviceio_t *	device,
		hw_gpio_t *	int_pin,
		const dev_ft6236_config_t *	config
	)

Initialize an FT6236-compatible touch controller over I2C.

Parameters

device	I2C device handle from hw_i2c_init() / hw_i2c_init_default() / hw_i2c_init_device(), already opened at the controller's address (see DEV_FT6236_I2C_ADDR_DEFAULT).
int_pin	Optional interrupt GPIO handle. Pass NULL to always poll.
config	Optional pointer to initialization options. Pass NULL to use default values.

Returns

FT6236 handle or NULL on failure.

dev_ft6236_irq_active()

bool dev_ft6236_irq_active

(

const dev_ft6236_t *

ft6236

)

Report whether the FT6236 interrupt line is currently asserted.

Parameters

ft6236

FT6236 handle.

Return values

true	The controller is signalling a pending update.
false	No pending update is signalled, or no interrupt pin exists.

dev_ft6236_poll()

bool dev_ft6236_poll	(	dev_ft6236_t *	ft6236,
		dev_ft6236_touch_t	touches[DEV_FT6236_MAX_POINTS],
		uint8_t *	out_touch_count
	)

Poll the controller and parse the latest touch frame.

Parameters

ft6236	FT6236 handle.
touches	Array receiving parsed touch contacts, indexed by touch slot. Must have room for DEV_FT6236_MAX_POINTS entries.
out_touch_count	Optional pointer receiving number of active touch points. Pass NULL to ignore.

Return values

true	Read succeeded.
false	Read failed.

When an interrupt pin is configured, this function skips the I2C transaction when no touch is pending and the previous frame was already idle.