Thejasvi Magudilu Vijayaraj
This is a MIDI synthesizer with touchpads used for playing the notes. mbed will capture the touchpad press and release events and sends the appropriate MIDI commands to the PC. By using the C# windows forms application created by us, one can compose songs as though they were composed on a piano. We support all types of standard MIDI piano types.
Diff: main.cpp
- Revision:
- 0:e33f18af0471
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Thu Oct 13 06:17:30 2011 +0000
@@ -0,0 +1,257 @@
+#include <mbed.h>
+#include <string>
+#include <list>
+
+#include <mpr121.h>
+#include "NokiaLCD.h"
+
+
+DigitalOut led1(LED1);
+DigitalOut led2(LED2);
+DigitalOut led3(LED3);
+DigitalOut led4(LED4);
+
+// Pushbuttons to change the octaves of the touchpads
+InterruptIn octavePlus1(p18); // Pushbutton that increments the octave of touchpad1
+InterruptIn octaveMinus1(p17); // Pushbutton that decrements the octave of touchpad1
+InterruptIn octavePlus2(p16); // Pushbutton that increments the octave of touchpad2
+InterruptIn octaveMinus2(p15); // Pushbutton that decrements the octave of touchpad2
+
+// Create the interrupt receiver object on pin 26
+InterruptIn interrupt1(p26); // IRQ of touchpad1
+InterruptIn interrupt2(p8); // IRQ of touchpad2
+
+// Setup the Serial to the PC for debugging
+Serial pc(USBTX, USBRX);
+
+// Setup the i2c bus on pins 28 and 27
+I2C i2c1(p28, p27);
+I2C i2c2(p9,p10);
+
+
+//Setup NOKIA LCD
+NokiaLCD lcd(p5, p7, p12, p11, NokiaLCD::LCD6610); // mosi, sclk, cs, rst, type
+
+
+// Setup the Mpr121:
+// constructor(i2c object, i2c address of the mpr121)
+Mpr121 mpr121_1(&i2c1, Mpr121::ADD_VSS);
+Mpr121 mpr121_2(&i2c2, Mpr121::ADD_VSS);
+
+Timer t1; // to calulate delta time
+
+void midiEventGenerator1();
+void midiEventGenerator2();
+
+
+volatile char octave[2] = {0,1}; // Stores the current octave of both the touchpads
+volatile int prev_val[2] = {0,0}; // Stores the previous touchpad values
+volatile int cur_val[2] = {0,0}; // Stores the current touchpad values
+volatile int time_us = 0; // Stores the time between different events of the same touchpad
+
+
+const int backgroundColor = 0x0000FF;
+const int graphBarColor = 0xFFFFFF;
+const int graphAxesColor = 0xFFFFFF;
+
+int t = 0;
+
+// Key hit/release interrupt routine for touch pad 1
+void fallInterrupt1()
+{
+ time_us = t1.read_us();
+ t1.stop();
+ t1.reset();
+ t1.start();
+ cur_val[0] = mpr121_1.read(0x00);
+ cur_val[0] += mpr121_1.read(0x01)<<8;
+
+ midiEventGenerator1();
+}
+
+
+// Key hit/release interrupt routine for touch pad 2
+void fallInterrupt2()
+{
+ time_us = t1.read_us();
+ t1.stop();
+ t1.reset();
+ t1.start();
+ cur_val[1] = mpr121_2.read(0x00);
+ cur_val[1] += mpr121_2.read(0x01)<<8;
+
+ midiEventGenerator2();
+}
+
+void octaveIncrement1()
+{
+ if(octave[0] < 9)
+ octave[0]++;
+
+ // Update the octave number on the LCD
+ lcd.fill(48,8,8,8,backgroundColor);
+ lcd.locate(6,1);
+ lcd.printf("%d",octave[0]);
+
+ wait(0.5);
+}
+
+void octaveIncrement2()
+{
+ if(octave[1] < 9)
+ octave[1]++;
+
+ lcd.fill(112,8,8,8,backgroundColor);
+ lcd.locate(14,1);
+ lcd.printf("%d",octave[1]);
+
+ wait(0.5);
+}
+
+void octaveDecrement1()
+{
+ if(octave[0] > 0)
+ octave[0]--;
+
+ lcd.fill(48,8,8,8,backgroundColor);
+ lcd.locate(6,1);
+ lcd.printf("%d",octave[0]);
+
+ wait(0.5);
+}
+
+void octaveDecrement2()
+{
+ if(octave[1] > 0)
+ octave[1]--;
+
+ lcd.fill(112,8,8,8,backgroundColor);
+ lcd.locate(14,1);
+ lcd.printf("%d",octave[1]);
+
+ wait(0.5);
+}
+
+void rx()
+{
+ // reset timer when new file is to be created
+ t1.stop();
+ t1.reset();
+ t1.start();
+
+ char temp = pc.getc();
+}
+
+int main()
+{
+ // Initialize LCD
+ lcd.background(backgroundColor);
+ lcd.cls();
+
+ lcd.fill(5,35,55,1,graphAxesColor);
+ lcd.fill(5,35,1,85,graphAxesColor);
+
+ lcd.fill(65,35,55,1,graphAxesColor);
+ lcd.fill(65,35,1,85,graphAxesColor);
+
+ lcd.locate(0,1);
+ lcd.printf("Octv: %d",octave[0]);
+
+ lcd.locate(8,1);
+ lcd.printf("Octv: %d",octave[1]);
+
+ // Initialize the pushbutton interrupts
+ octavePlus1.mode(PullUp);
+ octavePlus1.fall(&octaveIncrement1);
+ octavePlus2.mode(PullUp);
+ octavePlus2.fall(&octaveIncrement2);
+ octaveMinus1.mode(PullUp);
+ octaveMinus1.fall(&octaveDecrement1);
+ octaveMinus2.mode(PullUp);
+ octaveMinus2.fall(&octaveDecrement2);
+
+
+ // for touch pad 1
+ interrupt1.mode(PullUp);
+ interrupt1.fall(&fallInterrupt1);
+ t1.reset();
+ t1.start();
+
+
+ // for touch pad 2
+ interrupt2.mode(PullUp);
+ interrupt2.fall(&fallInterrupt2);
+
+ // Setup interrupt for serial port rx. This is used to reset the deltatime timer when a new file is created on the PC
+ pc.attach(&rx);
+
+ int temp = 0;
+ while (1)
+ {
+ temp ^= 1;
+ led1 = temp;;
+ wait(0.5);
+ }
+}
+
+
+void midiEventGenerator1()
+{
+ int temp;
+
+ // Evaluate for touch pad 1
+ temp = cur_val[0] ^ prev_val[0];
+
+ for(int i = 0; i < 12; i++)
+ {
+ if((temp & 1) == 1)
+ {
+ int mask = (1 << i);
+
+ if((cur_val[0] & mask) == mask)
+ {
+ pc.printf("on%01d%03d%010d",0,((octave[0] * 12) + i), time_us); // sending format: channel, note, deltaTime_uS
+ lcd.fill(6,(36 + (7 * i)),50,6,graphBarColor); // Display the FFT
+ }
+ else
+ {
+ pc.printf("of%01d%03d%010d",0,((octave[0] * 12) + i), time_us);
+ lcd.fill(6,(36 + (7 * i)),50,6,backgroundColor);
+ }
+ }
+ temp = temp >> 1;
+ }
+
+ prev_val[0] = cur_val[0];
+
+}
+
+void midiEventGenerator2()
+{
+ int temp;
+
+ // Evaluate for touch pad 2
+ temp = cur_val[1] ^ prev_val[1];
+
+ for(int i = 0; i < 12; i++)
+ {
+ if((temp & 1) == 1)
+ {
+ int mask = (1 << i);
+
+ if((cur_val[1] & mask) == mask)
+ {
+ pc.printf("on%01d%03d%010d",0,((octave[1] * 12) + i), time_us);
+ lcd.fill(66,(36 + (7 * i)),50,6,graphBarColor);
+ }
+ else
+ {
+ pc.printf("of%01d%03d%010d",0,((octave[1] * 12) + i), time_us);
+ lcd.fill(66,(36 + (7 * i)),50,6,backgroundColor);
+ }
+ }
+ temp = temp >> 1;
+ }
+
+ prev_val[1] = cur_val[1];
+}
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