Diff: main.cpp

Revision:

0:0036725a5dc3

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Tue Nov 30 23:52:45 2010 +0000
@@ -0,0 +1,224 @@
+#include "mbed.h"
+
+const int TRIGGER_LEN = 128;
+const int NBUFF = 10;
+
+typedef enum {s_Init, s_Input} PC_State;
+
+DigitalOut myled_1(LED1);
+DigitalOut myled_2(LED2);
+AnalogIn input_1(p17);
+AnalogIn input_2(p20);
+DigitalIn charger_1(p16);
+DigitalIn charger_2(p19);
+DigitalOut ground_1(p15);
+DigitalOut ground_2(p18);
+Serial pc(USBTX, USBRX); // tx, rx
+
+int buff_1, buff_2;
+int last_1, last_2;
+char key;
+
+// PC_State pc_State = s_Init;
+char tmptr[TRIGGER_LEN];
+char trigger[TRIGGER_LEN];
+char detectW[TRIGGER_LEN];
+size_t tmp_len, tr_len;
+size_t window_sz, match_len;
+
+bool pcinput;           // then true, PC is reading input from the host. Otherwise, wait user press the 'S' button.
+void getSerialInput();
+int touchSense_1(void);
+int touchSense_2(void);
+int buttonTouched();
+char readTouchInput();
+int isIdentity(char* cp1, char* cp2, size_t len);
+void windowShift(char* wpt, size_t len);
+void printDetectWindow(char* wpt, size_t len);
+
+int main() {
+    tmp_len = 0;
+    tr_len = 0;
+    pcinput = 0;
+    match_len = 0;
+    window_sz = 0;
+    memset(tmptr, 0, TRIGGER_LEN);
+    memset(trigger, 0, TRIGGER_LEN);
+    memset(detectW, 0, TRIGGER_LEN);
+    pc.attach(&getSerialInput);
+    pc.printf("Please input the trigger string in the format of Sbbb...bbbE\n\r");
+    while(buttonTouched()) {
+        if (tr_len) {
+            if (window_sz == tr_len) {
+                windowShift(detectW, tr_len);
+                detectW[tr_len - 1] = key;
+                printDetectWindow(detectW, window_sz);
+                if (isIdentity(detectW, trigger, tr_len)) {
+                    pc.printf("MATCH\n\r");
+                }
+            } else {
+                detectW[window_sz++] = key;
+                printDetectWindow(detectW, window_sz);
+                if (window_sz == tr_len) {
+                        if (isIdentity(detectW, trigger, tr_len)) {
+                        pc.printf("MATCH\n\r");
+                    }
+                }
+            }
+        }
+    }
+}
+
+void getSerialInput() {
+    char tmp_char = pc.getc();
+    if (tmp_char == 'S') {
+        tmp_len = 0;
+        tr_len = 0;         // If user starts to input a new trigger string
+                            // automatically disable the old one. At this period,
+                            // no touch input would be reponsed.      
+        window_sz = 0;
+        memset(tmptr, 0, TRIGGER_LEN);
+        pcinput = 1;
+        pc.putc(tmp_char);
+    } else if (tmp_char == '0' || tmp_char == '1') {
+        if (pcinput && tmp_len != TRIGGER_LEN - 1) {
+            tmptr[tmp_len++] = tmp_char;
+            pc.putc(tmp_char);
+        } else {
+            // It is not time for input now.
+            pc.printf("HOST ERROR\n\r");
+        }
+    } else if (tmp_char == 'E') {
+        if (tmp_len == 0) {
+            pc.printf("HOST ERROR\n\r");
+        } else {
+            pcinput = 0;
+            match_len = 0;
+            tmptr[tmp_len] = '\0';
+            memcpy(trigger, tmptr, TRIGGER_LEN);
+            tr_len = tmp_len;
+            pc.putc(tmp_char);
+            pc.printf("\n\rThe trigger string is %s\n\r", trigger);
+            pc.printf("Please start to touch the button\n\r");
+            pc.printf("Or you can the trigger string in the format of Sbbb...bbbE\n\r");
+        }
+    } else if (tmp_char == ' ') {
+        // Simply ignore the whitespace
+    } else {
+        // Invalid input
+        if (pcinput) {
+            pc.printf("\n\rHOST ERROR\n\rS");
+            for (int i = 0; i < tmp_len; i++) {
+                pc.putc(tmptr[i]);
+            }
+        } else {        
+            pc.printf("HOST ERROR\n\r");
+        }
+    }
+}
+
+
+int buttonTouched() {
+    key = readTouchInput();
+    return 1;
+}
+
+int touchSense_1(void) {
+    float sample;
+    ground_1 = 0;
+    charger_1.mode(PullUp);
+    charger_1.mode(PullNone);
+    sample=input_1.read();
+    if (sample < 0.3) {
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+int touchSense_2(void) {
+    float sample;
+    ground_2 = 0;
+    charger_2.mode(PullUp);
+    charger_2.mode(PullNone);
+    sample=input_2.read();
+    if (sample < 0.3) {
+        return 1;
+    } else {
+        return 0;
+    }
+}
+
+/*
+ * In this implementation, "multicouch" is naturely not supported.
+ * When two button is touch at the same time, '0' will be always returned
+ * instead of '1'.
+ */
+char readTouchInput() {
+    while (1) {
+        if (touchSense_1()) {
+            myled_1 = 1;
+            if (!last_1) {
+                last_1 = 1;
+                buff_1 = NBUFF;
+            }
+        } else {
+            if (last_1) {
+                last_1 = 0;
+            } else {
+                if (buff_1 == 0) {
+                    if (myled_1) {
+                        myled_1 = 0;
+                        return '0';
+                    }
+                } else {
+                    buff_1--;
+                }
+            }
+        }
+        if (touchSense_2()) {
+            myled_2 = 1;
+            if (!last_2) {
+                last_2 = 1;
+                buff_2 = NBUFF;
+            }
+        } else {
+            if (last_2) {
+                last_2 = 0;
+            } else {
+                if (buff_2 == 0) {
+                    if (myled_2) {
+                        myled_2 = 0;
+                        return '1';
+                    }
+                } else {
+                    buff_2--;
+                }
+            }
+        }
+        wait(0.005);
+    }
+}
+
+int isIdentity(char* cp1, char* cp2, size_t len) {
+    for (int i = 0; i != len; i++) {
+        if (cp1[i] != cp2[i]) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+void windowShift(char* wpt, size_t len) {
+    for (int i = 0; i != len - 1; i++) {
+        wpt[i] = wpt[i + 1];
+    }
+}
+
+void printDetectWindow(char* wpt, size_t len) {
+    pc.printf("Current detection window: ");
+    for (int i = 0; i != len; i++) {
+        pc.putc(wpt[i]);
+    }
+    pc.printf("\n\r");
+}
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