void addSamples() {

		    // TODO, NOT YET IMPLEMENTED
			if (freeEntries < SAMPLES_PER_BUFFER) {return false;}
			
			//int16_t* dst = &audioBuffer[bufHead];
			//memcpy(dst, samples, SAMPLES_PER_BUFFER*sizeof(int16_t));
			//bufHead = (bufHead + SAMPLES_PER_BUFFER) % NUM_ENTRIES;
			
			
			//curBuffer = (curBuffer + 1) % NUM_BUFFERS;
			
			for (uint16_t i = 0; i < SAMPLES_PER_BUFFER; ++i) {
				audioBuffer[bufHead] = samples[i];
				bufHead = (bufHead + 1) % NUM_ENTRIES;
			}
			freeEntries -= SAMPLES_PER_BUFFER;
			
			arm_dcache_flush_delete(audioBuffer, NUM_ENTRIES*sizeof(int16_t));
			
			return true;
		#endif

}

void setup() {
	
	attachInterruptVector(IRQ_SAI2, isrAudio);
			NVIC_ENABLE_IRQ(IRQ_SAI2);
			NVIC_SET_PRIORITY(IRQ_SAI2, 127);
			I2S2_TCSR |= 1<<8;	
	
}





// interrupt service routine
	    static void isrAudio() {
				
			// TODO, not yet implemented

			static constexpr volatile uint16_t* txReg = (uint16_t *)((uint32_t)&I2S2_TDR0 + 2);
			//static constexpr uint16_t* txReg = (uint16_t *)((uint32_t)&I2S2_TDR0 );

			//if (CHANNELS == 2) {
			    const uint16_t sample1 = audioBuffer[bufTail];
				//*txReg = sample1;
				bufTail = (bufTail + 1) & (NUM_ENTRIES-1);
				if (freeEntries < NUM_ENTRIES) {++freeEntries;}
				*txReg = sample1;
			//}
			
		}