ugfx/drivers/ginput/touch/ADS7843/ginput_lld_mouse.c
2013-07-21 22:20:37 +02:00

131 lines
3.0 KiB
C

/*
* This file is subject to the terms of the GFX License. If a copy of
* the license was not distributed with this file, you can obtain one at:
*
* http://ugfx.org/license.html
*/
/**
* @file drivers/ginput/touch/ADS7843/ginput_lld_mouse.c
* @brief GINPUT Touch low level driver source for the ADS7843.
*
* @defgroup Mouse Mouse
* @ingroup GINPUT
* @{
*/
#include "gfx.h"
#if (GFX_USE_GINPUT && GINPUT_NEED_MOUSE) /*|| defined(__DOXYGEN__)*/
#include "ginput/lld/mouse.h"
#include "ginput_lld_mouse_board.h"
#if defined(GINPUT_MOUSE_YX_INVERTED) && GINPUT_MOUSE_YX_INVERTED
#define CMD_X 0x91
#define CMD_Y 0xD1
#else
#define CMD_X 0xD1
#define CMD_Y 0x91
#endif
static uint16_t sampleBuf[7];
static coord_t lastx, lasty;
/**
* @brief 7-point median filtering code for touch samples
*
* @note This is an internally used routine only.
*
* @notapi
*/
static void filter(void) {
uint16_t temp;
int i,j;
for(i = 0; i < 4; i++) {
for(j = i; j < 7; j++) {
if(sampleBuf[i] > sampleBuf[j]) {
/* Swap the values */
temp = sampleBuf[i];
sampleBuf[i] = sampleBuf[j];
sampleBuf[j] = temp;
}
}
}
}
/**
* @brief Initialise the mouse/touch.
*
* @notapi
*/
void ginput_lld_mouse_init(void) {
init_board();
}
/**
* @brief Read the mouse/touch position.
*
* @param[in] pt A pointer to the structure to fill
*
* @note For drivers that don't support returning a position
* when the touch is up (most touch devices), it should
* return the previous position with the new Z value.
* The z value is the pressure for those touch devices
* that support it (-100 to 100 where > 0 is touched)
* or, 0 or 100 for those drivers that don't.
*
* @notapi
*/
void ginput_lld_mouse_get_reading(MouseReading *pt) {
uint16_t i;
// If touch-off return the previous results
if (!getpin_pressed()) {
pt->x = lastx;
pt->y = lasty;
pt->z = 0;
pt->buttons = 0;
return;
}
// Read the port to get the touch settings
aquire_bus();
/* Get the X value
* Discard the first conversion - very noisy and keep the ADC on hereafter
* till we are done with the sampling. Note that PENIRQ is disabled while reading.
* Finally switch on PENIRQ once again - perform a dummy read.
* Once we have the readings, find the medium using our filter function
*/
read_value(CMD_X);
for(i = 0; i < 7; i++)
sampleBuf[i] = read_value(CMD_X);
read_value(CMD_X-1);
filter();
lastx = (coord_t)sampleBuf[3];
/* Get the Y value using the same process as above */
read_value(CMD_Y);
for(i = 0; i < 7; i++)
sampleBuf[i] = read_value(CMD_Y);
read_value(CMD_Y-1);
filter();
lasty = (coord_t)sampleBuf[3];
// Release the bus
release_bus();
// Return the results
pt->x = lastx;
pt->y = lasty;
pt->z = 100;
pt->buttons = GINPUT_TOUCH_PRESSED;
}
#endif /* GFX_USE_GINPUT && GINPUT_NEED_MOUSE */
/** @} */