Diff: TouchSense.h

Revision:

0:fefcd43a3608

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TouchSense.h	Thu Jan 22 08:48:09 2015 +0000
@@ -0,0 +1,195 @@
+#include "mbed.h"
+#include "rtos.h"
+
+//#define DEBUG
+
+// for profiling
+#define PRSIZE 500
+#define START_THREAD 1
+
+class FrameRate {
+    float rate;
+    int counter;
+    Timer timer;
+
+public:    
+    FrameRate() {
+        rate = 0;
+        counter = 0;
+        timer.start();
+    }
+    
+    void update() {
+        counter++;
+        if (counter == 10) {
+            rate = 1000*10.0/timer.read_ms();
+            counter = 0;
+            timer.reset();
+        }
+    }
+    
+    float getRate() {
+        return rate;
+    }
+};
+
+class TouchSense
+{
+    float V0;
+    float V1;
+    float C1;
+
+    DigitalOut &dout;
+    AnalogIn &ain;
+
+    static const int BUFSIZE = 3;
+    int buf[BUFSIZE];
+    int bufindex;
+
+    int state;
+
+    FrameRate rater;
+    
+    static void threadStarter(void const *p);
+    Thread _thread;
+public:
+    TouchSense(DigitalOut &dout, AnalogIn &ain): V0(0.0), V1(0.5), C1(20), dout(dout), ain(ain),
+     _thread(&TouchSense::threadStarter, this, osPriorityNormal, 10240) {
+        // XXX: 0.5 must be defined automatically
+        state = 0;
+        calibrate();
+
+        _thread.signal_set(START_THREAD);
+    }
+
+    int touched() {
+        return state;
+    }
+
+private:
+    void calibrate() {
+        printf("TouchSense.calibrate\r\n");
+        dout.write(0);
+        Thread::wait(1000);
+
+        // initialize V0
+        float s = 0.0;
+        for (int i = 0; i < 10; i++) {
+            float level = ain.read();
+            printf("TouchSense.calibrate: level=%f\r\n", level);
+            if (s < level)
+                s = level;
+            Thread::wait(100);
+        }
+        V0 = s;
+        printf("TouchSense.calibrate: V0=%f\r\n", V0);
+
+        // initialize buf, bufindex, and C1
+        for (int i = 0; i < BUFSIZE; i++) {
+            buf[i] = sense();
+            printf("TouchSense.calibrate: sense=%d\r\n", buf[i]);
+        }
+        int sum = 0;
+        for (int i = 0; i < BUFSIZE; i++)
+            sum += buf[i];
+        C1 = sum*3.0/BUFSIZE;   // XXX: 3 is a magic number
+        bufindex = 0;
+        printf("TouchSense.calibrate: C1=%f\r\n", C1);
+    }
+
+    void loop() {
+        _thread.signal_wait(START_THREAD);
+        printf("TouchSense.loop: start\r\n");
+        for (;;) {
+            int r = sense();
+            if (r == -1)
+                buf[bufindex] = C1+1;
+            else
+                buf[bufindex] = r;
+            bufindex = (bufindex+1)%BUFSIZE;
+
+            int sum = 0;
+            for (int i = 0; i < BUFSIZE; i++)
+                sum += buf[i];
+            float avg = (float)sum/BUFSIZE;
+
+            if (avg > C1)       // touhced for 0.001*BUFSIZE sec
+                state = 1;  // touched
+            else
+                state = 0;  // untouched
+
+            rater.update();
+            Thread::wait(5);
+        }
+    }
+
+    int sense() {
+        DigitalIn prswitch(p5);
+        prswitch.mode(PullUp);
+
+        // step 1
+        int xxx = 0;
+        dout.write(0);
+#ifdef DEBUG
+        printf("touched: ain=%f\n\r", ain.read());
+#endif
+        while (ain.read() > V0) {
+            xxx++;
+            if (xxx > 100) {           // 0.1 sec
+                printf("touched: warning ain=%f\n\r", ain.read());
+                return -1;
+            }
+            Thread::wait(1);
+        }
+
+        // step 2
+        dout.write(1);
+
+        // step 3
+        int count = 0;
+
+        if (prswitch) {
+            // mode: normal
+            for  (;;) {
+                if (count > C1)
+                    break;
+                if (ain.read() > V1)
+                    break;
+                count++;
+            }
+#ifdef DEBUG
+            printf("touched: count=%d\r\n", count);
+#endif
+        } else {    
+            // mode: profiling
+            printf("rate = %f\r\n", rater.getRate());
+
+            float prdata[PRSIZE];
+            float prtime[PRSIZE];
+            Timer timer;
+
+            timer.start();
+            for (;;) {
+                prdata[count] = ain.read();
+                prtime[count] = timer.read();
+                if (prdata[count] > V1)
+                    break;
+                count++;
+                if (count == PRSIZE) {
+                    printf("touched: warning[count==PRSIZE]\r\n");
+                    count--;
+                    break;
+                }
+            }
+            printf("# n=%d V0=%f V1=%f\r\n", count+1, V0, V1);
+            for (int i = 0; i <= count; i++)
+                printf("%f %f\r\n", prtime[i], prdata[i]);
+            printf("\r\n");
+        }
+
+        // step 4
+        dout.write(0);
+
+        return count;
+    }
+};