Resistive Touch - ADS7843 Controller

Low-level driver for the ADS7843 touch controller.

This driver provides access to the main features of the ADS7843 controller.

Functions
void	ads7843_disable_interrupt (void)
	Disable interrupts on touch event. More...
void	ads7843_enable_interrupt (void)
	Enable interrupts on touch event. More...
void	ads7843_get_raw_point (uint32_t *p_x, uint32_t *p_y)
	Get the touch raw coordinates. More...
uint32_t	ads7843_init (void)
	Initialize the SPI communication with the ADS7843 controller. More...
uint32_t	ads7843_is_pressed (void)
	Return the touch screen status, pressed or not. More...
void	ads7843_set_handler (void(*p_handler)(uint32_t, uint32_t))
	Set the touch interrupt handler. More...

void ads7843_disable_interrupt

(

void

)

Disable interrupts on touch event.

Disable the interrupt

References pio_disable_pin_interrupt().

void ads7843_enable_interrupt

(

void

)

Enable interrupts on touch event.

Enable the interrupt

References pio_enable_pin_interrupt().

void ads7843_get_raw_point	(	uint32_t *	p_x,
		uint32_t *	p_y
	)

Get the touch raw coordinates.

Parameters

p_x	Pointer to an integer representing the X value.
p_y	Pointer to an integer representing the Y value.

Disable interrupt to quickly evaluate the coordinates

Get X position

Get Y position

Switch to full power mode

Re-enable interrupt

References ads7843_send_cmd(), CMD_ENABLE_PENIRQ, CMD_X_POSITION, CMD_Y_POSITION, pio_disable_pin_interrupt(), and pio_enable_pin_interrupt().

uint32_t ads7843_init

(

void

)

Initialize the SPI communication with the ADS7843 controller.

Board specific chip select configuration

References ads7843_send_cmd(), ADS7843_SPI_BAUDRATE, CMD_ENABLE_PENIRQ, spi_device::id, spi_enable(), spi_master_init(), spi_master_setup_device(), SPI_MODE_0, and spi_select_device().

uint32_t ads7843_is_pressed

(

void

)

Return the touch screen status, pressed or not.

Returns

1 if the touchscreen is pressed, 0 otherwise.

References ioport_get_pin_level(), and IOPORT_PIN_LEVEL_LOW.

void ads7843_set_handler

(

void(*)(uint32_t, uint32_t)

p_handler

)

Set the touch interrupt handler.

Note

This handler will be called whenever a touch event is detected by the ADS7843 controller.

Parameters

p_handler

Interrupt handler function pointer.

Initialize interrupts

Enable the interrupt

References pio_enable_pin_interrupt().