STMPE610

This module provides a device-level API for STMPE610 resistive touch controllers over SPI (e.g. More...

Collaboration diagram for STMPE610:

Data Structures
struct	dev_stmpe610_config_t
	Optional STMPE610 initialization options. More...
struct	dev_stmpe610_touch_t
	The single touch contact reported to a dev_stmpe610_callback_t - unlike a capacitive controller, STMPE610 is resistive and only ever reports one point at a time. More...

Typedefs
typedef struct dev_stmpe610_t	dev_stmpe610_t
	Opaque STMPE610 handle.
typedef void(*	dev_stmpe610_callback_t) (dev_stmpe610_t *stmpe610, const dev_stmpe610_touch_t *touch, void *userdata)
	Touch event callback invoked from dev_stmpe610_poll(). More...

Enumerations
enum	dev_stmpe610_touch_event_t { dev_stmpe610_touch_up = 0, dev_stmpe610_touch_down = 1, dev_stmpe610_touch_move = 2 }
	Touch contact state reported to a dev_stmpe610_callback_t. More...

Lifecycle
void	dev_stmpe610_default_config (dev_stmpe610_config_t *config)
	Fill an STMPE610 config struct with safe defaults. More...
dev_stmpe610_t *	dev_stmpe610_init (hw_deviceio_t *device, hw_gpio_t *int_pin, dev_stmpe610_callback_t callback, void *userdata, const dev_stmpe610_config_t *config)
	Initialize an STMPE610 resistive touch controller over SPI. More...
void	dev_stmpe610_deinit (dev_stmpe610_t *stmpe610)
	Deinitialize an STMPE610 controller. More...

Properties
bool	dev_stmpe610_irq_active (const dev_stmpe610_t *stmpe610)
	Report whether the STMPE610 interrupt line is currently asserted. More...

Methods
void	dev_stmpe610_poll (dev_stmpe610_t *stmpe610)
	Poll the controller, invoking the callback if the touch state changed. More...

Detailed Description

This module provides a device-level API for STMPE610 resistive touch controllers over SPI (e.g.

Adafruit's 2.8" PiTFT resistive touch display, which pairs it with an ILI9341 display controller on the same SPI bus but a separate chip-select).

Typedef Documentation

dev_stmpe610_callback_t

typedef void(* dev_stmpe610_callback_t) (dev_stmpe610_t *stmpe610, const dev_stmpe610_touch_t *touch, void *userdata)

Touch event callback invoked from dev_stmpe610_poll().

Parameters

stmpe610	STMPE610 handle.
touch	The touch contact that changed.
userdata	User-defined data pointer passed to dev_stmpe610_init().

Definition at line 76 of file stmpe610.h.

Enumeration Type Documentation

dev_stmpe610_touch_event_t

enum dev_stmpe610_touch_event_t

Touch contact state reported to a dev_stmpe610_callback_t.

Enumerator
dev_stmpe610_touch_up	Contact lifted - no longer touching.
dev_stmpe610_touch_down	A new contact.
dev_stmpe610_touch_move	An existing contact moved.

Definition at line 39 of file stmpe610.h.

             {
  dev_stmpe610_touch_up = 0,   
  dev_stmpe610_touch_down = 1, 
  dev_stmpe610_touch_move = 2, 
} dev_stmpe610_touch_event_t;

Function Documentation

dev_stmpe610_default_config()

void dev_stmpe610_default_config

(

dev_stmpe610_config_t *

config

)

Fill an STMPE610 config struct with safe defaults.

Parameters

config

Config structure to initialize.

dev_stmpe610_deinit()

void dev_stmpe610_deinit

(

dev_stmpe610_t *

stmpe610

)

Deinitialize an STMPE610 controller.

Parameters

stmpe610

STMPE610 handle.

Passing NULL is safe and is a no-op.

dev_stmpe610_init()

dev_stmpe610_t* dev_stmpe610_init	(	hw_deviceio_t *	device,
		hw_gpio_t *	int_pin,
		dev_stmpe610_callback_t	callback,
		void *	userdata,
		const dev_stmpe610_config_t *	config
	)

Initialize an STMPE610 resistive touch controller over SPI.

Parameters

device	SPI device handle from hw_spi_init() / hw_spi_init_default() / hw_spi_init_device(), already opened on the controller's own chip-select (separate from any display sharing the same bus).
int_pin	Optional interrupt GPIO handle. Pass NULL to always poll.
callback	Optional callback invoked from dev_stmpe610_poll() each time the touch state actually changes. Pass NULL if only dev_stmpe610_irq_active() or the interrupt pin's own level matters.
userdata	User-defined data pointer passed to callback.
config	Optional pointer to initialization options. Pass NULL to use default values.

Returns

STMPE610 handle, or NULL on failure (including a chip ID mismatch - nothing responding correctly at the given chip-select).

dev_stmpe610_irq_active()

bool dev_stmpe610_irq_active

(

const dev_stmpe610_t *

stmpe610

)

Report whether the STMPE610 interrupt line is currently asserted.

Parameters

stmpe610

STMPE610 handle.

Return values

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

dev_stmpe610_poll()

void dev_stmpe610_poll

(

dev_stmpe610_t *

stmpe610

)

Poll the controller, invoking the callback if the touch state changed.

Parameters

stmpe610

STMPE610 handle.

When an interrupt pin is configured, this function skips the SPI transaction entirely when no touch is pending and the previous sample was already idle. The callback registered with dev_stmpe610_init() (if any) is invoked only when a new contact, a moved contact, or a lifted contact is actually detected - never for an unchanged, still-idle, or still-touching-with-nothing-new poll.