tsi_sensor.h

00001 /* Freescale Semiconductor Inc.
00002  *
00003  * mbed Microcontroller Library
00004  * (c) Copyright 2009-2012 ARM Limited.
00005  *
00006  * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
00007  * and associated documentation files (the "Software"), to deal in the Software without
00008  * restriction, including without limitation the rights to use, copy, modify, merge, publish,
00009  * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
00010  * Software is furnished to do so, subject to the following conditions:
00011  *
00012  * The above copyright notice and this permission notice shall be included in all copies or
00013  * substantial portions of the Software.
00014  *
00015  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
00016  * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00017  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
00018  * DAMAGES OR OTHER 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 THE SOFTWARE.
00020  */
00021 
00022 #ifndef TSISENSOR_H
00023 #define TSISENSOR_H
00024 
00025 /**
00026 * TSISensor example
00027 *
00028 * @code
00029 * #include "mbed.h"
00030 * #include "TSISensor.h"
00031 *
00032 * int main(void) {
00033 *    DigitalOut led(LED_GREEN);
00034 *    TSIElectrode elec0(9);
00035 *    TSIElectrode elec1(10);
00036 *    TSIAnalogSlider tsi(elec0, elec1, 40);
00037 *
00038 *    while (true) {
00039 *        printf("slider percentage: %f%\r\n", tsi.readPercentage());
00040 *        printf("slider distance: %dmm\r\n", tsi.readDistance());
00041 *        wait(1);
00042 *        led = !led;
00043 *    }
00044 * }
00045 * @endcode
00046 */
00047 #define NO_TOUCH 0
00048 
00049 /** TSI Electrode with simple data required for touch detection.
00050  */
00051 class TSIElectrode {
00052 public:
00053     /** Initialize electrode.
00054      */
00055     TSIElectrode(PinName pin) : _threshold(100) {
00056         _channel = getTSIChannel(pin);
00057     }
00058 
00059     /** Initialize electrode.
00060      */
00061     TSIElectrode(uint32_t tsi_channel) : _threshold(100) {
00062         _channel = (uint8_t)tsi_channel;
00063     }
00064     /** Set baseline.
00065      */
00066     void setBaseline(uint32_t baseline) {
00067         _baseline = (uint16_t)baseline;
00068     }
00069     /** Set threshold.
00070      */
00071     void setThreshold(uint32_t threshold) {
00072         _threshold = (uint16_t)threshold;
00073     }
00074     /** Set signal.
00075      */
00076     void setSignal(uint32_t signal) {
00077         _signal = (uint16_t)signal;
00078     }
00079     /** Get baseline.
00080      */
00081     uint32_t getBaseline() {
00082         return _baseline;
00083     }
00084     /** Get delta.
00085      */
00086     uint32_t getDelta() {
00087         int32_t delta = getSignal() - getBaseline();
00088         if (delta < 0) {
00089             return 0;
00090         } else {
00091             return delta;
00092         }
00093     }
00094     /** Get signal.
00095      */
00096     uint32_t getSignal() {
00097         return _signal;
00098     }
00099     /** Get threshold.
00100      */
00101     uint32_t getThreshold() {
00102         return _threshold;
00103     }
00104     /** Get channel.
00105      */
00106     uint32_t getChannel() {
00107         return _channel;
00108     }
00109     /** Get TSI Channel for PinName.
00110      *
00111      * @returns TSI channel ID for use in constructor of TSIAnalogSlider and TSIElectrode.
00112      * @throws compile-time error if target is not supported, or runtime error if pin does not match any channel.
00113      */
00114     static uint8_t getTSIChannel(PinName pin) {
00115 #if   defined (TARGET_KL25Z) || defined (TARGET_KL46Z)       
00116         switch(pin) {
00117             //these are 
00118             case PTA0: return 1;
00119             case PTA1: return 2;
00120             case PTA2: return 3;
00121             case PTA3: return 4;
00122             case PTA4: return 5;
00123             case PTB0: return 0;
00124             case PTB1: return 6;
00125             case PTB2: return 7;
00126             case PTB3: return 8;
00127             case PTB16: return 9;
00128             case PTB17: return 10;
00129             case PTB18: return 11;
00130             case PTB19: return 12;
00131             case PTC0: return 13;
00132             case PTC1: return 14;
00133             default: error("PinName provided to TSIElectrode::getTSIChannel() does not correspond to any known TSI channel.");
00134         }
00135 # elif   defined (TARGET_KL05Z)        
00136 # else
00137     #error "Unknown target for TSIElectrode::getTSIChannel() - only supports KL25Z so far."
00138 # endif   
00139         return 0xFF; //should never get here
00140     }
00141     
00142 private:
00143     uint8_t  _channel;
00144     uint16_t _signal;
00145     uint16_t _baseline;
00146     uint16_t _threshold;
00147 };
00148 
00149 /** Analog slider which consists of two electrodes.
00150  */
00151 class TSIAnalogSlider {
00152 public:
00153     /**
00154      *
00155      *   Initialize the TSI Touch Sensor with the given PinNames
00156      */
00157     TSIAnalogSlider(PinName elec0, PinName elec1, uint32_t range);
00158     /**
00159      *   Initialize the TSI Touch Sensor
00160      */
00161     TSIAnalogSlider(uint32_t elec0, uint32_t elec1, uint32_t range);
00162     /**
00163      * Read Touch Sensor percentage value
00164      *
00165      * @returns percentage value between [0 ... 1]
00166      */
00167     float readPercentage();
00168     /**
00169      * Read Touch Sensor distance
00170      *
00171      * @returns distance in mm. The value is between [0 ... _range]
00172      */
00173     uint32_t readDistance();
00174     /** Get current electrode.
00175      */
00176     TSIElectrode* getCurrentElectrode() {
00177         return _current_elec;
00178     }
00179     /** Set current electrode which is being measured.
00180      */
00181     void setCurrentElectrode(TSIElectrode *elec){
00182         _current_elec = elec;
00183     }
00184     /** Get next electrode.
00185      */
00186     TSIElectrode* getNextElectrode(TSIElectrode* electrode) {
00187         if (electrode->getChannel() == _elec0.getChannel()) {
00188             return &_elec1;
00189         } else {
00190             return &_elec0;
00191         }
00192     }
00193     /** Return absolute distance position.
00194      */
00195     uint32_t getAbsoluteDistance() {
00196         return  _absolute_distance_pos;
00197     }
00198     /** Return absolute precentage position.
00199      */
00200     uint32_t getAbsolutePosition() {
00201         return _absolute_percentage_pos;
00202     }
00203     /** Set value to the scan in progress flag.
00204      */
00205     void setScan(uint32_t scan) {
00206         _scan_in_progress = scan;
00207     }
00208     /** Return instance to Analog slider. Used in tsi irq.
00209      */
00210     static TSIAnalogSlider *getInstance() {
00211         return _instance;
00212     }
00213 private:
00214     void initObject(void); //shared constructor code
00215     void sliderRead(void);
00216     void selfCalibration(void);
00217     void setSliderPercPosition(uint32_t elec_num, uint32_t position) {
00218         _percentage_position[elec_num] = position;
00219     }
00220     void setSliderDisPosition(uint32_t elec_num, uint32_t position) {
00221         _distance_position[elec_num] = position;
00222     }
00223     void setAbsolutePosition(uint32_t position) {
00224         _absolute_percentage_pos = position;
00225     }
00226     void setAbsoluteDistance(uint32_t distance) {
00227         _absolute_distance_pos = distance;
00228     }
00229 private:
00230     TSIElectrode  _elec0;
00231     TSIElectrode  _elec1;
00232     uint8_t       _scan_in_progress;
00233     TSIElectrode* _current_elec;
00234     uint8_t       _percentage_position[2];
00235     uint8_t       _distance_position[2];
00236     uint32_t      _absolute_percentage_pos;
00237     uint32_t      _absolute_distance_pos;
00238     uint8_t       _range;
00239 protected:
00240     static TSIAnalogSlider *_instance;
00241 };
00242 
00243 #endif