main.cpp

00001 /**
00002 * A simple app to make Volume Control with the KL25Z onboard Touch Slider
00003 * 
00004 * Simply use the top and bottom part of the slider as buttons.
00005 *
00006 * Green led's intensity is controlled by the slider.
00007 * The Red component of the RGB led is changing intensity as you tilt the board on the X coordinate to have multiple actions at the same time.
00008 */
00009 
00010 #include "mbed.h"
00011 #include "MMA8451Q.h"
00012 #include "USBKeyboard.h"
00013 #include "TSISensor.h"
00014 
00015 #define MMA8451_I2C_ADDRESS (0x1d<<1)
00016 
00017 int main(void) {
00018     ///get leds, and set def. values
00019     PwmOut bled(LED_BLUE);
00020     bled=0.8;
00021     PwmOut rled(LED_RED);
00022     rled=1;
00023     PwmOut gled(LED_GREEN);
00024     gled=1;
00025     ///initializing the accelerometer
00026     MMA8451Q acc(PTE25, PTE24, MMA8451_I2C_ADDRESS);
00027     bled=0.6;
00028     //USB Keyboard interface:
00029     USBKeyboard keyboard;
00030     bled=0.4;
00031     //Touch Slider:
00032     TSISensor tsi;
00033     bled=0.2;
00034 
00035     ///switch on blue led
00036     bled=0.9;
00037     ///Wait until keyboard is configured
00038     while (!keyboard.configured()) {
00039         bled=0.1;
00040         wait(1);
00041         bled=0.9;
00042         wait(1);
00043     }
00044     bled=1;
00045 
00046     float current=-1; //< Current state of Slider
00047     float newRead; //< New readings of the slider
00048 
00049     while (true) {
00050         newRead=tsi.readPercentage();
00051         gled=1.0 - newRead;
00052         /// only if the slider is touched
00053         if (newRead>0)
00054             if (current!=newRead) {
00055                 ///and you have a different reading.
00056                 ///this is basically for not letting the volume be changed in every .1 seconds, and keeping the code responsive
00057                 ///you could have a counter on every 10th reading or so.
00058                 current=newRead;
00059                 if (current<0.4)
00060                     //if touched in the bottom half lower the volume
00061                     keyboard.mediaControl(KEY_VOLUME_DOWN);
00062                 else
00063                     if (current<0.6)
00064                         //if touched in the bottom half lower the volume
00065                         keyboard.mediaControl(KEY_PLAY_PAUSE);
00066                     else
00067                     //if touched in the top half rise the volume
00068                     keyboard.mediaControl(KEY_VOLUME_UP);
00069             }
00070         rled = 1.0 - (abs(acc.getAccX())/2);
00071         wait(0.1);
00072     }
00073 }