Seeed_QTouch/Seeed_QTouch.cpp

/*
    QTouch Library
    2014 Copyright (c) Seeed Technology Inc.  All right reserved.

    Author: ZhangKun & Loovee
    2013-3-20

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include <Wire.h>
#include <Arduino.h>
#include "Seeed_QTouch.h"


SeeedQTouch::SeeedQTouch() {
    Wire.begin();
}


// Check chip ID
int SeeedQTouch::chipPresent(void) {
    if (readReg(QTOUCH_REG_CHIPID) == 0x2e) {
        return 1;
    }
    return 0;
}

// if certain key touched, return 1 - touched, 0 untouched
unsigned char SeeedQTouch::isTouch(int key) {
    if (key > 7) {
        return 0;    // err input
    }
    unsigned char st = getState();
    return ((0x01 << key)&st);          // if touched return 1, else return 0
}

// return all key state, bit0 for key0, bit1 for key1....
unsigned char SeeedQTouch::getState() {
    return readReg(0x03);
}

int SeeedQTouch::touchNum() {
    unsigned char state = getState();
    if (0 == state) {
        return -1;
    }

    for (int i = 0; i < 7; i++) {
        if ((state >> i) & 0x01) {
            return i;
        }
    }

    return -1;
}

// Set group (0-3) for a key or disable the key (255)
int SeeedQTouch::setGroup(uint8_t key, uint8_t group) {
    uint8_t value;
    if (key > 6) {
        return -1;
    }
    if (group < 4) {
        value = readReg(QTOUCH_REG_AVEASK0 + key) & 0xfc;
        if (value == 0) {
            value = 8 << 2; //AVE default
        }
    } else if (group == 0xff) {
        value = 0; //Key disabled
        group = 1; //AKS default
    } else {
        return -1;
    }
    writeReg(QTOUCH_REG_AVEASK0 + key, value | group);
    return 0;
}


// read register
unsigned char SeeedQTouch::readReg(unsigned char addr_reg) {

    Wire.beginTransmission(ADDR_QTOUCH);
    Wire.write(addr_reg); // register to read
    Wire.endTransmission();

    Wire.requestFrom(ADDR_QTOUCH, 1); // read a byte

    while (Wire.available()) {
        return Wire.read();
    }
}

// write data to register
unsigned char SeeedQTouch::writeReg(unsigned char addr_reg, unsigned char dta) {    // write register
    Wire.beginTransmission(ADDR_QTOUCH);
    Wire.write(addr_reg); // register to read
    Wire.write(dta);
    Wire.endTransmission();
}

SeeedQTouch QTouch;