ads7843.c File Reference

API driver for component ADS7843.

Copyright (c) 2011-2018 Microchip Technology Inc. and its subsidiaries.

#include "ads7843.h"
#include "conf_ads7843.h"
#include "board.h"
#include "ioport.h"
#include "pio_handler.h"
#include "pio.h"
#include "spi_master.h"

Macros
#define	ADS7843_BUFSIZE   3
#define	ADS7843_SPI_BAUDRATE   1000000
	Frequence rate for sending one bit. More...
#define	ADS7843_TIMEOUT   5000000
#define	ADS_CTRL_DFR   (1 << 2)
	SER/DFR. More...
#define	ADS_CTRL_EIGHT_BITS_MOD   (1 << 3)
	Mode. More...
#define	ADS_CTRL_PD0   (1 << 0)
	PD0. More...
#define	ADS_CTRL_PD1   (1 << 1)
	PD1. More...
#define	ADS_CTRL_START   (1 << 7)
	Start Bit. More...
#define	ADS_CTRL_SWITCH_SHIFT   4
	Address setting. More...
#define	CMD_ENABLE_PENIRQ   ((1 << ADS_CTRL_SWITCH_SHIFT) | ADS_CTRL_START)
	Enable penIRQ. More...
#define	CMD_X_POSITION
	Get Y position command. More...
#define	CMD_Y_POSITION
	Get X position command. More...
#define	DELAY_BEFORE_SPCK   200
	2us min (tCSS) <=> 200/100 000 000 = 2us More...
#define	DELAY_BETWEEN_CONS_COM   0xf
	5us min (tCSH) <=> (32 * 15) / (100 000 000) = 5us More...

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...
static uint32_t	ads7843_send_cmd (uint8_t uc_cmd)
	Send a command to the ADS7843 touch controller. More...
void	ads7843_set_handler (void(*p_handler)(uint32_t, uint32_t))
	Set the touch interrupt handler. More...

#define ADS7843_BUFSIZE   3

Referenced by ads7843_send_cmd().

#define ADS7843_SPI_BAUDRATE   1000000

Frequence rate for sending one bit.

Referenced by ads7843_init().

#define ADS7843_TIMEOUT   5000000

#define ADS_CTRL_DFR   (1 << 2)

SER/DFR.

#define ADS_CTRL_EIGHT_BITS_MOD   (1 << 3)

Mode.

#define ADS_CTRL_PD0   (1 << 0)

PD0.

#define ADS_CTRL_PD1   (1 << 1)

PD1.

#define ADS_CTRL_START   (1 << 7)

Start Bit.

#define ADS_CTRL_SWITCH_SHIFT   4

Address setting.

#define CMD_ENABLE_PENIRQ   ((1 << ADS_CTRL_SWITCH_SHIFT) | ADS_CTRL_START)

Enable penIRQ.

Referenced by ads7843_get_raw_point(), and ads7843_init().

#define CMD_X_POSITION

Value:

((5 << ADS_CTRL_SWITCH_SHIFT) | ADS_CTRL_START |\
        ADS_CTRL_PD0 | ADS_CTRL_PD1)

Get Y position command.

Referenced by ads7843_get_raw_point().

#define CMD_Y_POSITION

Value:

((1 << ADS_CTRL_SWITCH_SHIFT) | ADS_CTRL_START |\
        ADS_CTRL_PD0 | ADS_CTRL_PD1)

Get X position command.

Referenced by ads7843_get_raw_point().

#define DELAY_BEFORE_SPCK   200

2us min (tCSS) <=> 200/100 000 000 = 2us

#define DELAY_BETWEEN_CONS_COM   0xf

5us min (tCSH) <=> (32 * 15) / (100 000 000) = 5us

static uint32_t ads7843_send_cmd ( uint8_t  uc_cmd )

static

Send a command to the ADS7843 touch controller.

Parameters

uc_cmd

command to send.

Returns

Command result.

(volatile declaration needed for code optimisation by compiler)

References ADS7843_BUFSIZE, BOARD_ADS7843_SPI_BASE, SPI_ERROR_TIMEOUT, spi_is_rx_full(), spi_is_tx_ready(), spi_read_single(), SPI_TIMEOUT, spi_write_single(), and timeout.

Referenced by ads7843_get_raw_point(), and ads7843_init().