mpr121.cpp

00001 /*
00002 Copyright (c) 2011 Anthony Buckton (abuckton [at] blackink [dot} net {dot} au)
00003  
00004 Permission is hereby granted, free of charge, to any person obtaining a copy
00005 of this software and associated documentation files (the "Software"), to deal
00006 in the Software without restriction, including without limitation the rights
00007 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008 copies of the Software, and to permit persons to whom the Software is
00009 furnished to do so, subject to the following conditions:
00010  
00011 The above copyright notice and this permission notice shall be included in
00012 all copies or substantial portions of the Software.
00013  
00014 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00020 THE SOFTWARE.
00021 */
00022 
00023 #include <mbed.h>
00024 #include <sstream>
00025 #include <string>
00026 #include <list>
00027 
00028 #include <mpr121.h>
00029     
00030 Mpr121::Mpr121(I2C *i2c, Address i2cAddress)
00031 {
00032     this->i2c = i2c;
00033     
00034     address = i2cAddress;
00035            
00036     // Configure the MPR121 settings to default
00037     this->configureSettings();
00038 }
00039 
00040    
00041 void Mpr121::configureSettings()
00042 {
00043     // Put the MPR into setup mode
00044     this->write(ELE_CFG,0x00);
00045  /*   
00046     this->write(AUTO_CFG_U,201);
00047 this->write(AUTO_CFG_T,181);
00048 this->write(AUTO_CFG_L,131);
00049 this->write(AUTO_CFG_0,0x09);
00050   */
00051     // Electrode filters for when data is > baseline
00052     unsigned char gtBaseline[] = {
00053          0x01,  //MHD_R
00054          0x01,  //NHD_R 
00055          0x00,  //NCL_R
00056          0x00   //FDL_R
00057          };
00058          
00059     writeMany(MHD_R,gtBaseline,4);   
00060                  
00061      // Electrode filters for when data is < baseline   
00062      unsigned char ltBaseline[] = {
00063         0x01,   //MHD_F
00064         0x01,   //NHD_F
00065         0xFF,   //NCL_F
00066         0x02    //FDL_F
00067         };
00068         
00069     writeMany(MHD_F,ltBaseline,4);
00070         
00071     // Electrode touch and release thresholds
00072     unsigned char electrodeThresholds[] = {
00073         E_THR_T, // Touch Threshhold
00074         E_THR_R  // Release Threshold
00075         };
00076 
00077     for(int i=0; i<12; i++){
00078         int result = writeMany((ELE0_T+(i*2)),electrodeThresholds,2);
00079     }   
00080 
00081     // Proximity Settings
00082     unsigned char proximitySettings[] = {
00083         0xff,   //MHD_Prox_R
00084         0xff,   //NHD_Prox_R
00085         0x00,   //NCL_Prox_R
00086         0x00,   //FDL_Prox_R
00087         0x01,   //MHD_Prox_F
00088         0x01,   //NHD_Prox_F
00089         0xFF,   //NCL_Prox_F
00090         0xff,   //FDL_Prox_F
00091         0x00,   //NHD_Prox_T
00092         0x00,   //NCL_Prox_T
00093         0x00    //NFD_Prox_T
00094         };
00095     writeMany(MHDPROXR,proximitySettings,11);
00096 
00097     unsigned char proxThresh[] = {
00098         PROX_THR_T, // Touch Threshold
00099         PROX_THR_R  // Release Threshold
00100         };
00101     writeMany(EPROXTTH,proxThresh,2); 
00102        
00103     this->write(FIL_CFG,0x04);
00104     
00105     // Set the electrode config to transition to active mode
00106     this->write(ELE_CFG,0x0c);
00107 
00108 
00109 
00110 
00111 }
00112 
00113 void Mpr121::setElectrodeThreshold(int electrode, unsigned char touch, unsigned char release){
00114     
00115     if(electrode > 11) return;
00116     
00117     // Get the current mode
00118     unsigned char mode = this->read(ELE_CFG);
00119     
00120     // Put the MPR into setup mode
00121     this->write(ELE_CFG,0x00);
00122     
00123     // Write the new threshold
00124     this->write((ELE0_T+(electrode*2)), touch);
00125     this->write((ELE0_T+(electrode*2)+1), release);
00126     
00127     //Restore the operating mode
00128     this->write(ELE_CFG, mode);
00129 }
00130     
00131     
00132 unsigned char Mpr121::read(int key){
00133 
00134     unsigned char data[2];
00135     
00136     //Start the command
00137     i2c->start();
00138 
00139     // Address the target (Write mode)
00140     int ack1= i2c->write(address);
00141 
00142     // Set the register key to read
00143     int ack2 = i2c->write(key);
00144 
00145     // Re-start for read of data
00146     i2c->start();
00147 
00148     // Re-send the target address in read mode
00149     int ack3 = i2c->write(address+1);
00150 
00151     // Read in the result
00152     data[0] = i2c->read(0); 
00153 
00154     // Reset the bus        
00155     i2c->stop();
00156 
00157     return data[0];
00158 }
00159 
00160 
00161 int Mpr121::write(int key, unsigned char value){
00162     
00163     //Start the command
00164     i2c->start();
00165 
00166     // Address the target (Write mode)
00167     int ack1= i2c->write(address);
00168 
00169     // Set the register key to write
00170     int ack2 = i2c->write(key);
00171 
00172     // Read in the result
00173     int ack3 = i2c->write(value); 
00174 
00175     // Reset the bus        
00176     i2c->stop();
00177     
00178     return (ack1+ack2+ack3)-3;
00179 }
00180 
00181 
00182 int Mpr121::writeMany(int start, unsigned char* dataSet, int length){
00183     //Start the command
00184     i2c->start();
00185 
00186     // Address the target (Write mode)
00187     int ack= i2c->write(address);
00188     if(ack!=1){
00189         return -1;
00190     }
00191     
00192     // Set the register key to write
00193     ack = i2c->write(start);
00194     if(ack!=1){
00195         return -1;
00196     }
00197 
00198     // Write the date set
00199     int count = 0;
00200     while(ack==1 && (count < length)){
00201         ack = i2c->write(dataSet[count]);
00202         count++;
00203     } 
00204     // Stop the cmd
00205     i2c->stop();
00206     
00207     return count;
00208 }
00209       
00210 
00211 bool Mpr121::getProximityMode(){
00212     if(this->read(ELE_CFG) > 0x0c)
00213         return true;
00214     else
00215         return false;
00216 }
00217 
00218 void Mpr121::setProximityMode(bool mode){
00219     this->write(ELE_CFG,0x00);
00220     if(mode){
00221         this->write(ELE_CFG,0x30); //Sense proximity from ALL pads
00222     } else {
00223         this->write(ELE_CFG,0x0c); //Sense touch, all 12 pads active.
00224     }
00225 }
00226 
00227 
00228 int Mpr121::readTouchData(){
00229     return this->read(0x00);
00230 }