Unverified Commit 4ef39130 authored by Birte Kristina Friesel's avatar Birte Kristina Friesel
Browse files

adc.startSampling: Use DMA to populate buffer

parent fc390815

include/arch/msp430fr5994lp/driver/adc.h

+7 −15
Original line number Diff line number Diff line
@@ -13,14 +13,10 @@ class ADC { 
	private:

		ADC(ADC const &copy);



		uint16_t bufsize;

		uint16_t bufpos;

		uint16_t *buf16;

		uint8_t *buf8;

		volatile bool bufferFull;



	public:

		ADC() : bufsize(0), bufpos(0), buf16(NULL), buf8(NULL), bufferFull(false) {}

		ADC() : bufferFull(false) {}



		float getTemp();

		float getVCC();
@@ -28,7 +24,12 @@ class ADC { 
		void startSampling(uint16_t *buf, uint16_t bufsize);

		void stopSampling();



		inline bool doneSampling()

		inline void setBufferFull()

		{

			bufferFull = true;

		}



		inline bool isBufferFull()

		{

			if (bufferFull) {

				bufferFull = false;
@@ -36,15 +37,6 @@ class ADC { 
			}

			return false;

		}



		inline void storeReading(uint16_t value)

		{

			buf16[bufpos++] = value;

			bufpos %= bufsize;

			if (bufpos == 0) {

				bufferFull = true;

			}

		}

};



extern ADC adc;

src/arch/msp430fr5994lp/driver/adc.cc

+14 −14
Original line number Diff line number Diff line
@@ -152,16 +152,16 @@ void ADC::startSampling(uint16_t *buf, uint16_t bufsize) 
	P3SEL0 |= BIT0;

	P3SEL1 |= BIT0;



	// raise an interrupt after each sample

	ADC12IER0 = ADC12IE1;

	ADC12IFGR0 = ADC12IFG1;



	// clear pending interrupts

	ADC12IV = 0;



	buf16 = buf;

	this->bufsize = bufsize;



	// Use DMA Channel 0 to automatically copy readings to buf

	DMACTL0 = DMA0TSEL__DMA0TRIG26;

	DMACTL4 = DMARMWDIS;

	DMA0CTL = DMADSTINCR_3;

	DMA0SA = ADC12_B_BASE + OFS_ADC12MEM1;

	DMA0DA = (uintptr_t)buf;

	DMA0SZ = bufsize;

	DMA0CTL |= DMAEN | DMAIE;



	// start sampling

	ADC12CTL0 |= ADC12ENC | ADC12SC;

}
@@ -174,11 +174,11 @@ void ADC::stopSampling() 
ADC adc;



#ifndef __acweaving

__attribute__((interrupt(ADC12_VECTOR))) void handle_adc_irq()

__attribute__((interrupt(DMA_VECTOR))) void handle_dma_irq()

{

	if (ADC12IV == 0x00e) {

		// ADC12MEM1

		adc.storeReading(ADC12MEM1);

	if (DMAIV == 0x02) {

		adc.setBufferFull();

		DMA0CTL |= DMAEN;

	}

}

#endif