/*------------------------------------------------------------------------------
--  This file is a part of the libuc, microcontroler library
--  Copyright (C) 2013, Alexis Jeandet
--
--  This program is free software; you can redistribute it and/or modify
--  it under the terms of the GNU General Public License as published by
--  the Free Software Foundation; either version 3 of the License, or
--  (at your option) any later version.
--
--  This program is distributed in the hope that it will be useful,
--  but WITHOUT ANY WARRANTY; without even the implied warranty of
--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--  GNU General Public License for more details.
--
--  You should have received a copy of the GNU General Public License
--  along with this program; if not, write to the Free Software
--  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-------------------------------------------------------------------------------
--                 Author : Alexis Jeandet
--                   Mail : alexis.jeandet@member.fsf.org
-------------------------------------------------------------------------------*/

#include <ADS7843.h>
#include <core.h>

int ads7843init(ADS7843_t *dev, spi_t spidev, char config, void (*setnCS)(char), int (*busy)())
{
    dev->spidev = spidev;
    dev->setnCS = setnCS;
    dev->busy = busy;
    dev->setnCS(1);
    dev->config = config & ADS7843_CONFIG_MASK;
    dev->xMax = 1000;
    dev->xMin = 0;
    dev->yMax = 1000;
    dev->yMin = 0;
    dev->zeroRtouch = 0;
    dev->zeroX = 500;
    dev->zeroY = 500;
    dev->delta = 200;
    return 1;
}

unsigned int __ads7843read(ADS7843_t *dev,char cfg)
{
    unsigned int data;
    dev->setnCS(0);
    while(dev->busy());
    spiputw(dev->spidev,ADS7843_START|dev->config|cfg);
    data= (0x0FF & spigetw2(dev->spidev,0))<<8;
    data+= 0x0FF & spigetw2(dev->spidev,0);
    dev->setnCS(1);
    return (data>>4);
}

int ads7843read(ADS7843_t *dev,int* x,int* y)
{
    *x=0;
    *y=0;
    for(int i=0;i<32;i++)
    {
        *x += __ads7843read(dev,ADS7843_MEAS_X_POS_DIFF|ADS7843_POWER_REF_ON|ADS7843_POWER_ADC_ON);
        *y += __ads7843read(dev,ADS7843_MEAS_Y_POS_DIFF|ADS7843_POWER_REF_ON|ADS7843_POWER_ADC_ON);
    }
    *x>>=5;
    *y>>=5;
    *x = ((*x-dev->xMin)*1000)/(dev->xMax-dev->xMin);
    *y = ((*y-dev->yMin)*1000)/(dev->yMax-dev->yMin);
    return 1;
}




int ads7843readRtouch(ADS7843_t *dev)
{
#define avg 32
    int z1=0,z2=0,x=0;
    for(int i=0;i<avg;i++)
    {
        x  += __ads7843read(dev,ADS7843_MEAS_X_POS_DIFF|ADS7843_POWER_REF_ON|ADS7843_POWER_ADC_ON);
        z1 += __ads7843read(dev,ADS7843_MEAS_Z1_POS_DIFF|ADS7843_POWER_REF_ON|ADS7843_POWER_ADC_ON);
        z2 += __ads7843read(dev,ADS7843_MEAS_Z2_POS_DIFF|ADS7843_POWER_REF_ON|ADS7843_POWER_ADC_ON);
    }
    return (x/(4096/avg))*((z2/z1)-1);
}


int ads7843calibrate(ADS7843_t *dev, uint16_t zeroX, uint16_t zeroY, uint16_t zeroRtouch, uint16_t xMin, uint16_t xMax, uint16_t yMin, uint16_t yMax, char delta)
{
    dev->xMax = xMax;
    dev->xMin = xMin;
    dev->yMax = yMax;
    dev->yMin = yMin;
    dev->zeroRtouch = zeroRtouch;
    dev->zeroX = zeroX;
    dev->zeroY = zeroY;
    dev->delta = delta;
}


int ads7843isPenTouching(ADS7843_t *dev)
{
    int rtc= ads7843readRtouch(dev);
    return ((rtc+dev->delta) < dev->zeroRtouch);

}