TSISensor.cpp

00001 #if defined(TARGET_KL25Z)
00002 /* Freescale Semiconductor Inc.
00003  * (c) Copyright 2004-2005 Freescale Semiconductor, Inc.
00004  * (c) Copyright 2001-2004 Motorola, Inc. 
00005  *
00006  * mbed Microcontroller Library
00007  * (c) Copyright 2009-2012 ARM Limited.
00008  *
00009  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
00010  * and associated documentation files (the "Software"), to deal in the Software without
00011  * restriction, including without limitation the rights to use, copy, modify, merge, publish,
00012  * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
00013  * Software is furnished to do so, subject to the following conditions:
00014  *
00015  * The above copyright notice and this permission notice shall be included in all copies or
00016  * substantial portions of the Software.
00017  *
00018  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
00019  * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00020  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
00021  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00022  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00023  */
00024 
00025 #include "mbed.h"
00026 #include "TSISensor.h"
00027 
00028 #define NO_TOUCH                 0
00029 #define SLIDER_LENGTH           40 //LENGTH in mm
00030 #define TOTAL_ELECTRODE          2
00031 
00032 #define TSI0a        0
00033 #define TSI1         1
00034 #define TSI2         2
00035 #define TSI3         3
00036 #define TSI4         4
00037 #define TSI5         5
00038 #define TSI6         6
00039 #define TSI7         7
00040 #define TSI8         8
00041 #define TSI9         9
00042 #define TSI10        10
00043 #define TSI11        11
00044 #define TSI12        12
00045 #define TSI13        13
00046 #define TSI14        14
00047 #define TSI15        15
00048 
00049 /*Chose the correct TSI channel for the electrode number*/
00050 #define ELECTRODE0   TSI9
00051 #define ELECTRODE1   TSI10
00052 #define ELECTRODE2   TSI0a
00053 #define ELECTRODE3   TSI1
00054 #define ELECTRODE4   TSI2
00055 #define ELECTRODE5   TSI3
00056 #define ELECTRODE6   TSI4
00057 #define ELECTRODE7   TSI5
00058 #define ELECTRODE8   TSI6
00059 #define ELECTRODE9   TSI7
00060 #define ELECTRODE10  TSI8
00061 #define ELECTRODE11  TSI11
00062 #define ELECTRODE12  TSI12
00063 #define ELECTRODE13  TSI13
00064 #define ELECTRODE14  TSI14
00065 #define ELECTRODE15  TSI15
00066 
00067 #define THRESHOLD0   100
00068 #define THRESHOLD1   100
00069 #define THRESHOLD2   100
00070 #define THRESHOLD3   100
00071 #define THRESHOLD4   100
00072 #define THRESHOLD5   100
00073 #define THRESHOLD6   100
00074 #define THRESHOLD7   100
00075 #define THRESHOLD8   100
00076 #define THRESHOLD9   100
00077 #define THRESHOLD10   100
00078 #define THRESHOLD11   100
00079 #define THRESHOLD12   100
00080 #define THRESHOLD13   100
00081 #define THRESHOLD14   100
00082 #define THRESHOLD15   100
00083 
00084 static uint8_t total_electrode = TOTAL_ELECTRODE;
00085 static uint8_t elec_array[16]={ELECTRODE0,ELECTRODE1,ELECTRODE2,ELECTRODE3,ELECTRODE4,ELECTRODE5,
00086                                ELECTRODE6,ELECTRODE7,ELECTRODE8,ELECTRODE9,ELECTRODE10,ELECTRODE11,
00087                                ELECTRODE12,ELECTRODE13,ELECTRODE14,ELECTRODE15};
00088 static uint16_t gu16TSICount[16];
00089 static uint16_t gu16Baseline[16];
00090 static uint16_t gu16Threshold[16]={THRESHOLD0,THRESHOLD1,THRESHOLD2,THRESHOLD3,THRESHOLD4,THRESHOLD5,
00091                                    THRESHOLD6,THRESHOLD7,THRESHOLD8,THRESHOLD9,THRESHOLD10,THRESHOLD11,
00092                                    THRESHOLD12,THRESHOLD13,THRESHOLD14,THRESHOLD15};
00093 static uint16_t gu16Delta[16];
00094 static uint8_t ongoing_elec;
00095 static uint8_t end_flag = 1;
00096 
00097 static uint8_t SliderPercentegePosition[2] = {NO_TOUCH,NO_TOUCH};
00098 static uint8_t SliderDistancePosition[2] = {NO_TOUCH,NO_TOUCH};
00099 static uint32_t AbsolutePercentegePosition = NO_TOUCH;
00100 static uint32_t AbsoluteDistancePosition = NO_TOUCH;
00101 
00102 static void tsi_irq();
00103 
00104 TSISensor::TSISensor() {
00105     SIM->SCGC5 |= SIM_SCGC5_PORTB_MASK;
00106     SIM->SCGC5 |= SIM_SCGC5_TSI_MASK;
00107 
00108     TSI0->GENCS |= (TSI_GENCS_ESOR_MASK
00109                    | TSI_GENCS_MODE(0)
00110                    | TSI_GENCS_REFCHRG(4)
00111                    | TSI_GENCS_DVOLT(0)
00112                    | TSI_GENCS_EXTCHRG(7)
00113                    | TSI_GENCS_PS(4)
00114                    | TSI_GENCS_NSCN(11)
00115                    | TSI_GENCS_TSIIEN_MASK
00116                    | TSI_GENCS_STPE_MASK
00117                    );
00118 
00119     TSI0->GENCS |= TSI_GENCS_TSIEN_MASK;
00120 
00121     NVIC_SetVector(TSI0_IRQn, (uint32_t)&tsi_irq);
00122     NVIC_EnableIRQ(TSI0_IRQn);
00123 
00124     selfCalibration();
00125 }
00126 
00127 
00128 void TSISensor::selfCalibration(void)
00129 {
00130     unsigned char cnt;
00131     unsigned char trigger_backup;
00132 
00133     TSI0->GENCS |= TSI_GENCS_EOSF_MASK;      // Clear End of Scan Flag
00134     TSI0->GENCS &= ~TSI_GENCS_TSIEN_MASK;    // Disable TSI module
00135 
00136     if(TSI0->GENCS & TSI_GENCS_STM_MASK)     // Back-up TSI Trigger mode from Application
00137         trigger_backup = 1;
00138     else
00139         trigger_backup = 0;
00140 
00141     TSI0->GENCS &= ~TSI_GENCS_STM_MASK;      // Use SW trigger
00142     TSI0->GENCS &= ~TSI_GENCS_TSIIEN_MASK;    // Enable TSI interrupts
00143 
00144     TSI0->GENCS |= TSI_GENCS_TSIEN_MASK;     // Enable TSI module
00145 
00146     for(cnt=0; cnt < total_electrode; cnt++)  // Get Counts when Electrode not pressed
00147     {
00148         TSI0->DATA = ((elec_array[cnt] << TSI_DATA_TSICH_SHIFT) );
00149         TSI0->DATA |= TSI_DATA_SWTS_MASK;
00150         while(!(TSI0->GENCS & TSI_GENCS_EOSF_MASK));
00151         TSI0->GENCS |= TSI_GENCS_EOSF_MASK;
00152         gu16Baseline[cnt] = (TSI0->DATA & TSI_DATA_TSICNT_MASK);
00153     }
00154 
00155     TSI0->GENCS &= ~TSI_GENCS_TSIEN_MASK;    // Disable TSI module
00156     TSI0->GENCS |= TSI_GENCS_TSIIEN_MASK;     // Enale TSI interrupt
00157     if(trigger_backup)                      // Restore trigger mode
00158         TSI0->GENCS |= TSI_GENCS_STM_MASK;
00159     else
00160         TSI0->GENCS &= ~TSI_GENCS_STM_MASK;
00161 
00162     TSI0->GENCS |= TSI_GENCS_TSIEN_MASK;     // Enable TSI module
00163 
00164     TSI0->DATA = ((elec_array[0]<<TSI_DATA_TSICH_SHIFT) );
00165     TSI0->DATA |= TSI_DATA_SWTS_MASK;
00166 }
00167 
00168 
00169 void TSISensor::sliderRead(void ) {
00170     if(end_flag) {
00171         end_flag = 0;
00172         if((gu16Delta[0] > gu16Threshold[0])||(gu16Delta[1] > gu16Threshold[1])) {
00173             SliderPercentegePosition[0] = (gu16Delta[0]*100)/(gu16Delta[0]+gu16Delta[1]);
00174             SliderPercentegePosition[1] = (gu16Delta[1]*100)/(gu16Delta[0]+gu16Delta[1]);
00175             SliderDistancePosition[0] = (SliderPercentegePosition[0]* SLIDER_LENGTH)/100;
00176             SliderDistancePosition[1] = (SliderPercentegePosition[1]* SLIDER_LENGTH)/100;
00177             AbsolutePercentegePosition = ((100 - SliderPercentegePosition[0]) + SliderPercentegePosition[1])/2;
00178             AbsoluteDistancePosition = ((SLIDER_LENGTH - SliderDistancePosition[0]) + SliderDistancePosition[1])/2;
00179          } else {
00180             SliderPercentegePosition[0] = NO_TOUCH;
00181             SliderPercentegePosition[1] = NO_TOUCH;
00182             SliderDistancePosition[0] = NO_TOUCH;
00183             SliderDistancePosition[1] = NO_TOUCH;
00184             AbsolutePercentegePosition = NO_TOUCH;
00185             AbsoluteDistancePosition = NO_TOUCH;
00186          }
00187     }
00188 }
00189 
00190 float TSISensor::readPercentage() {
00191     sliderRead();
00192     return (float)AbsolutePercentegePosition/100.0;
00193 }
00194 
00195 uint8_t TSISensor::readDistance() {
00196     sliderRead();
00197     return AbsoluteDistancePosition;
00198 }
00199 
00200 
00201 static void changeElectrode(void)
00202 {
00203     int16_t u16temp_delta;
00204 
00205     gu16TSICount[ongoing_elec] = (TSI0->DATA & TSI_DATA_TSICNT_MASK);          // Save Counts for current electrode
00206     u16temp_delta = gu16TSICount[ongoing_elec] - gu16Baseline[ongoing_elec];  // Obtains Counts Delta from callibration reference
00207     if(u16temp_delta < 0)
00208         gu16Delta[ongoing_elec] = 0;
00209     else
00210         gu16Delta[ongoing_elec] = u16temp_delta;
00211 
00212     //Change Electrode to Scan
00213     if(total_electrode > 1)  
00214     {
00215         if((total_electrode-1) > ongoing_elec)
00216             ongoing_elec++;
00217         else
00218             ongoing_elec = 0;
00219 
00220         TSI0->DATA = ((elec_array[ongoing_elec]<<TSI_DATA_TSICH_SHIFT) );
00221         TSI0->DATA |= TSI_DATA_SWTS_MASK;
00222     }
00223 }
00224 
00225 
00226 void tsi_irq(void)
00227 {
00228     end_flag = 1;
00229     TSI0->GENCS |= TSI_GENCS_EOSF_MASK; // Clear End of Scan Flag
00230     changeElectrode();
00231 }
00232 
00233 #endif // defined(TARGET_KL25Z)