Diff: TouchSensor/TouchSensor.cpp

Revision:

0:e062501cfe81

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TouchSensor/TouchSensor.cpp	Sun Dec 13 10:06:24 2015 +0000
@@ -0,0 +1,164 @@
+/* Freescale Semiconductor Inc.
+ * (c) Copyright 2004-2005 Freescale Semiconductor, Inc.
+ * (c) Copyright 2001-2004 Motorola, Inc. 
+ *
+ * mbed Microcontroller Library
+ * (c) Copyright 2009-2012 ARM Limited.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
+ * and associated documentation files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or
+ * substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
+ * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+ 
+ /*The code written by Freescale Semiconductors is used for reference*/
+ 
+#include "TouchSensor.h"
+
+#define SLIDER_LENGTH           40 //LENGTH in mm
+
+
+static uint8_t total_electrode = 3;
+static uint8_t elec_array[16]={9,10,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+static uint16_t gu16TSICount[16];
+static uint16_t gu16Baseline[16];
+static uint16_t gu16Threshold[16]={100,100,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
+static uint16_t gu16Delta[16];
+static uint8_t ongoing_elec;
+static uint8_t end_flag = 1;
+
+static uint8_t SliderPercentegePosition[2] = {0,0};
+static uint32_t AbsolutePercentegePosition = 0;
+
+static void tsi_irq();
+
+TouchSensor::TouchSensor() {
+    SIM->SCGC5 |= SIM_SCGC5_PORTB_MASK;
+    SIM->SCGC5 |= SIM_SCGC5_TSI_MASK;
+
+    TSI0->GENCS |= (TSI_GENCS_ESOR_MASK
+                   | TSI_GENCS_MODE(0)
+                   | TSI_GENCS_REFCHRG(4)
+                   | TSI_GENCS_DVOLT(0)
+                   | TSI_GENCS_EXTCHRG(7)
+                   | TSI_GENCS_PS(4)
+                   | TSI_GENCS_NSCN(11)
+                   | TSI_GENCS_TSIIEN_MASK
+                   | TSI_GENCS_STPE_MASK
+                   );
+
+    TSI0->GENCS |= TSI_GENCS_TSIEN_MASK;
+
+    NVIC_SetVector(TSI0_IRQn, (uint32_t)&tsi_irq);
+    NVIC_EnableIRQ(TSI0_IRQn);
+
+    selfCalibration();
+}
+
+
+void TouchSensor::selfCalibration(void)
+{
+    unsigned char cnt;
+    unsigned char trigger_backup;
+
+    TSI0->GENCS |= TSI_GENCS_EOSF_MASK;      // Clear End of Scan Flag
+    TSI0->GENCS &= ~TSI_GENCS_TSIEN_MASK;    // Disable TSI module
+
+    if(TSI0->GENCS & TSI_GENCS_STM_MASK)     // Back-up TSI Trigger mode from Application
+        trigger_backup = 1;
+    else
+        trigger_backup = 0;
+
+    TSI0->GENCS &= ~TSI_GENCS_STM_MASK;      // Use SW trigger
+    TSI0->GENCS &= ~TSI_GENCS_TSIIEN_MASK;    // Enable TSI interrupts
+
+    TSI0->GENCS |= TSI_GENCS_TSIEN_MASK;     // Enable TSI module
+
+    for(cnt=0; cnt < total_electrode; cnt++)  // Get Counts when Electrode not pressed
+    {
+        TSI0->DATA = ((elec_array[cnt] << TSI_DATA_TSICH_SHIFT) );
+        TSI0->DATA |= TSI_DATA_SWTS_MASK;
+        while(!(TSI0->GENCS & TSI_GENCS_EOSF_MASK));
+        TSI0->GENCS |= TSI_GENCS_EOSF_MASK;
+        gu16Baseline[cnt] = (TSI0->DATA & TSI_DATA_TSICNT_MASK);
+    }
+
+    TSI0->GENCS &= ~TSI_GENCS_TSIEN_MASK;    // Disable TSI module
+    TSI0->GENCS |= TSI_GENCS_TSIIEN_MASK;     // Enale TSI interrupt
+    if(trigger_backup)                      // Restore trigger mode
+        TSI0->GENCS |= TSI_GENCS_STM_MASK;
+    else
+        TSI0->GENCS &= ~TSI_GENCS_STM_MASK;
+
+    TSI0->GENCS |= TSI_GENCS_TSIEN_MASK;     // Enable TSI module
+
+    TSI0->DATA = ((elec_array[0]<<TSI_DATA_TSICH_SHIFT) );
+    TSI0->DATA |= TSI_DATA_SWTS_MASK;
+}
+
+void TouchSensor::sliderRead(void ) {
+    if(end_flag) {
+        end_flag = 0;
+        if((gu16Delta[0] > gu16Threshold[0])||(gu16Delta[1] > gu16Threshold[1])) {
+            SliderPercentegePosition[0] = (gu16Delta[0]*100)/(gu16Delta[0]+gu16Delta[1]);
+            SliderPercentegePosition[1] = (gu16Delta[1]*100)/(gu16Delta[0]+gu16Delta[1]);
+            AbsolutePercentegePosition = ((100 - SliderPercentegePosition[0]) + SliderPercentegePosition[1])/2;
+         } else {
+            SliderPercentegePosition[0] = 0;
+            SliderPercentegePosition[1] = 0;
+            AbsolutePercentegePosition = 0;
+         }
+    }
+}
+
+float TouchSensor::readPercentage() {
+    sliderRead();
+    return (float)AbsolutePercentegePosition/100.0;
+}
+
+
+uint16_t TouchSensor::readValue(uint8_t index)
+{
+    return gu16TSICount[index];
+}
+
+static void changeElectrode(void)
+{
+    int16_t u16temp_delta;
+
+    gu16TSICount[ongoing_elec] = (TSI0->DATA & TSI_DATA_TSICNT_MASK);          // Save Counts for current electrode
+    u16temp_delta = gu16TSICount[ongoing_elec] - gu16Baseline[ongoing_elec];  // Obtains Counts Delta from callibration reference
+    if(u16temp_delta < 0)
+        gu16Delta[ongoing_elec] = 0;
+    else
+        gu16Delta[ongoing_elec] = u16temp_delta;
+
+    //Change Electrode to Scan
+    if(total_electrode > 1)  
+    {
+        if((total_electrode-1) > ongoing_elec)
+            ongoing_elec++;
+        else
+            ongoing_elec = 0;
+
+        TSI0->DATA = ((elec_array[ongoing_elec]<<TSI_DATA_TSICH_SHIFT) );
+        TSI0->DATA |= TSI_DATA_SWTS_MASK;
+    }
+}
+
+void tsi_irq(void)
+{
+    end_flag = 1;
+    TSI0->GENCS |= TSI_GENCS_EOSF_MASK; // Clear End of Scan Flag
+    changeElectrode();
+}