JJ Dekker / Mbed 2 deprecated Totaleprogramma1

The project is not done yet

Dependencies:   USBHost USBHostXpad mbed-rtos mbed

Fork of Totaleprogramma by jordy morsinkhof

Speaker.h@1:da390b3b1330, 2015-03-02 (annotated)

Committer:
juliandekker
Date:
Mon Mar 02 10:58:30 2015 +0000
Revision:
1:da390b3b1330
Parent:
0:345f76c72b9a 
xbox controller robot

Who changed what in which revision?

UserRevisionLine numberNew contents of line
347467 0:345f76c72b9a 1 class Speaker
347467 0:345f76c72b9a 2 {
347467 0:345f76c72b9a 3 public:
347467 0:345f76c72b9a 4 Speaker(PinName pin) : _pin(pin) {
347467 0:345f76c72b9a 5 // _pin(pin) means pass pin to the Speaker Constructor
347467 0:345f76c72b9a 6 // precompute 64 sample points on one sine wave cycle
347467 0:345f76c72b9a 7 // used for continuous sine wave output later
347467 0:345f76c72b9a 8 for(int k=0; k<64; k++) {
347467 0:345f76c72b9a 9 Analog_out_data[k] = int (65536.0 * ((1.0 + sin((float(k)/64.0*6.28318530717959)))/2.0));
347467 0:345f76c72b9a 10 // scale the sine wave to 16-bits - as needed for AnalogOut write_u16 arg
347467 0:345f76c72b9a 11 }
347467 0:345f76c72b9a 12
347467 0:345f76c72b9a 13 }
347467 0:345f76c72b9a 14 // class method to play a note based on AnalogOut class
347467 0:345f76c72b9a 15 void PlayNote(float frequency, float duration, float volume) {
347467 0:345f76c72b9a 16 // scale samples using current volume level arg
347467 0:345f76c72b9a 17 for(int k=0; k<64; k++) {
347467 0:345f76c72b9a 18 Analog_scaled_data[k] = Analog_out_data[k] * volume;
347467 0:345f76c72b9a 19 }
347467 0:345f76c72b9a 20 // reset to start of sample array
347467 0:345f76c72b9a 21 i=0;
347467 0:345f76c72b9a 22 // turn on timer interrupts to start sine wave output
347467 0:345f76c72b9a 23 Sample_Period.attach(this, &Speaker::Sample_timer_interrupt, 1.0/(frequency*64.0));
347467 0:345f76c72b9a 24 // play note for specified time
347467 0:345f76c72b9a 25 wait(duration);
347467 0:345f76c72b9a 26 // turns off timer interrupts
347467 0:345f76c72b9a 27 Sample_Period.detach();
347467 0:345f76c72b9a 28 // sets output to mid range - analog zero
347467 0:345f76c72b9a 29 this->_pin.write_u16(32768);
347467 0:345f76c72b9a 30
347467 0:345f76c72b9a 31 }
347467 0:345f76c72b9a 32 private:
347467 0:345f76c72b9a 33 // sets up specified pin for analog using AnalogOut class
347467 0:345f76c72b9a 34 AnalogOut _pin;
347467 0:345f76c72b9a 35 // set up a timer to be used for sample rate interrupts
347467 0:345f76c72b9a 36 Ticker Sample_Period;
347467 0:345f76c72b9a 37
347467 0:345f76c72b9a 38 //variables used by interrupt routine and PlayNote
347467 0:345f76c72b9a 39 volatile int i;
347467 0:345f76c72b9a 40 short unsigned Analog_out_data[64];
347467 0:345f76c72b9a 41 short unsigned Analog_scaled_data[64];
347467 0:345f76c72b9a 42
347467 0:345f76c72b9a 43 // Interrupt routine
347467 0:345f76c72b9a 44 // used to output next analog sample whenever a timer interrupt occurs
347467 0:345f76c72b9a 45 void Sample_timer_interrupt(void) {
347467 0:345f76c72b9a 46 // send next analog sample out to D to A
347467 0:345f76c72b9a 47 this->_pin.write_u16(Analog_scaled_data[i]);
347467 0:345f76c72b9a 48 // increment pointer and wrap around back to 0 at 64
347467 0:345f76c72b9a 49 i = (i+1) & 0x03F;
347467 0:345f76c72b9a 50 }
347467 0:345f76c72b9a 51 };
347467 0:345f76c72b9a 52