Diff: main.cpp

Revision:

0:4755a81efb1d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon May 26 08:03:17 2014 +0000
@@ -0,0 +1,64 @@
+#include "mbed.h"
+#include "USBKeyboard.h"
+
+#define LOG(args...)        // printf(args)
+
+#define THRESHOLD   2
+#define TOUCH_N     6
+
+BusOut leds(LED1, LED2, LED3, LED4);
+Ticker tick;
+USBKeyboard keyboard;
+
+uint8_t       key_map[TOUCH_N] = {RIGHT_ARROW, LEFT_ARROW, DOWN_ARROW, UP_ARROW, ' ', '\n'};
+PinName       touch_pin[TOUCH_N] = {A0, A1, A2, A3, A4, A5};
+DigitalInOut *p_touch_io[TOUCH_N];
+
+uint8_t touch_data[TOUCH_N] = {0, };
+
+void detect(void)
+{
+    for (int i = 0; i < TOUCH_N; i++) {
+        uint8_t count = 0;
+        DigitalInOut *touch_io = p_touch_io[i];
+        
+        touch_io->input();
+        touch_data[i] <<= 1;
+        while (touch_io->read()) {
+            count++;
+            if (count > THRESHOLD) {
+                touch_data[i] |= 0x01;
+                break;
+            }
+        }
+        touch_io->output();
+        touch_io->write(1);
+        
+        if (0x01 == touch_data[i]) {            // a measurement is about the threshold, get a touch
+            leds = 1 << i;
+            keyboard.putc(key_map[i]);
+            LOG("No %d key is touched\r\n", i);
+        } else if (0x80 == touch_data[i]) {     // last 7 measurement is under the threshold, touch is released
+            leds = 0x00;
+            LOG("No %d key is released\r\n", i);
+        }
+    }
+}
+
+int main()
+{
+    // setup
+    for (int i = 0; i < TOUCH_N; i++) {
+        p_touch_io[i] = new DigitalInOut(touch_pin[i]);
+        p_touch_io[i]->mode(PullDown);
+        p_touch_io[i]->output();
+        p_touch_io[i]->write(1);
+    }
+    
+    tick.attach(detect, 1.0 / 64.0);
+    
+    while(1) {
+        // do something
+        wait(1);
+    }
+}