More code development

src/AudioEffectAnalogDelay.cpp

@@ -102,22 +102,44 @@ void AudioEffectAnalogDelay::update(void)
 	}
 
 	// Otherwise perform normal processing
+	// In order to make use of the SPI DMA, we need to request the read from memory first,
+	// then do other processing while it fills in the back.
+	audio_block_t *blockToOutput = nullptr; // this will hold the output audio
+    blockToOutput = allocate();
+    if (!blockToOutput) return; // skip this update cycle due to failure
+
+    // get the data. If using external memory with DMA, this won't be filled until
+    // later.
+    m_memory->getSamples(blockToOutput, m_delaySamples);
+
+    // If using DMA, we need something else to do while that read executes, so
+    // move on to input preprocessing
+
 	// Preprocessing
 	audio_block_t *preProcessed = allocate();
 	// mix the input with the feedback path in the pre-processing stage
 	m_preProcessing(preProcessed, inputAudioBlock, m_previousBlock);
 
+	// consider doing the BBD post processing here to use up more time while waiting
+	// for the read data to come back
 	audio_block_t *blockToRelease = m_memory->addBlock(preProcessed);
 	if (blockToRelease) release(blockToRelease);
 
-	// OUTPUT PROCESSING
-	audio_block_t *blockToOutput = nullptr;
-	blockToOutput = allocate();
+	// BACK TO OUTPUT PROCESSING
+//	audio_block_t *blockToOutput = nullptr;
+//	blockToOutput = allocate();
 
 	// copy the output data
-	if (!blockToOutput) return; // skip this time due to failure
-	// copy over data
-	m_memory->getSamples(blockToOutput, m_delaySamples);
+//	if (!blockToOutput) return; // skip this time due to failure
+//	// copy over data
+//	m_memory->getSamples(blockToOutput, m_delaySamples);
+
+	// Check if external DMA, if so, we need to copy out of the DMA buffer
+	if (m_externalMemory && m_memory->getSlot()->isUseDma()) {
+	    // Using DMA
+	    m_memory->readDmaBufferContents(blockToOutput);
+	}
+
 	// perform the wet/dry mix mix
 	m_postProcessing(blockToOutput, inputAudioBlock, blockToOutput);
 	transmit(blockToOutput);

src/BASpiMemory.cpp

@@ -355,8 +355,8 @@ void BASpiMemoryDMA::begin(void)
 // are done before continuing.
 void BASpiMemoryDMA::write(size_t address, uint8_t *data, size_t numBytes)
 {
-	while ( m_txTransfer->busy()) {}
-	uint16_t transferCount = numBytes + 4;
+	while ( m_txTransfer->busy()) {} // wait until not busy
+	uint16_t transferCount = numBytes + 4; // transfer must be increased by the SPI command and address
 	m_setSpiCmdAddr(SPI_WRITE_CMD, address, m_txBuffer);
 	memcpy(m_txBuffer+4, data, numBytes);
 	*m_txTransfer = DmaSpi::Transfer(m_txBuffer, transferCount, nullptr, 0, m_cs);
@@ -394,8 +394,9 @@ void BASpiMemoryDMA::zero16(size_t address, size_t numWords)
 	m_spiDma->registerTransfer(*m_txTransfer);
 }
 
-void BASpiMemoryDMA::read(size_t address, uint8_t *data, size_t numBytes)
+void BASpiMemoryDMA::read(size_t address, uint8_t *dest, size_t numBytes)
 {
+    UNUSED(dest)
 	while ( m_rxTransfer->busy()) {}
 	uint16_t transferCount = numBytes + 4;
 	m_setSpiCmdAddr(SPI_READ_CMD, address, m_rxBuffer);
@@ -405,6 +406,7 @@ void BASpiMemoryDMA::read(size_t address, uint8_t *data, size_t numBytes)
 
 void BASpiMemoryDMA::read16(size_t address, uint16_t *dest, size_t numWords)
 {
+    UNUSED(dest)
 	while ( m_rxTransfer->busy()) {}
 	m_setSpiCmdAddr(SPI_READ_CMD, address, m_rxBuffer);
 	size_t numBytes = sizeof(uint16_t)*numWords;
@@ -413,9 +415,10 @@ void BASpiMemoryDMA::read16(size_t address, uint16_t *dest, size_t numWords)
 	m_spiDma->registerTransfer(*m_rxTransfer);
 }
 
-void BASpiMemoryDMA::readBufferContents(size_t bufferOffset, uint8_t *dest, size_t numBytes)
+void BASpiMemoryDMA::readBufferContents(uint8_t *dest, size_t numBytes, size_t bufferOffset)
 {
-	memcpy(dest, m_rxBuffer+4, numBytes);
+    while (m_rxTransfer->busy()) {} // ensure transfer is complete
+	memcpy(dest, m_rxBuffer+4+bufferOffset, numBytes);
 }
 
 } /* namespace BAGuitar */

src/BASpiMemory.h

@@ -115,7 +115,7 @@ class BASpiMemoryDMA : public BASpiMemory {
 	/// read a single 8-bit data word from the specified address
 	/// @param address the address in the SPI RAM to read from
 	/// @return the data that was read
-	void read(size_t address, uint8_t *data, size_t numBytes) override;
+	void read(size_t address, uint8_t *dest, size_t numBytes) override;
 
 	/// read a block 16-bit data word from the specified address
 	/// @param address the address in the SPI RAM to read from
@@ -125,7 +125,7 @@ class BASpiMemoryDMA : public BASpiMemory {
 
 
 	void begin() override;
-	void readBufferContents(size_t bufferOffset, uint8_t *dest, size_t numBytes);
+	void readBufferContents(uint8_t *dest, size_t numBytes, size_t bufferOffset = 0);
 
 private:
 	AbstractDmaSpi<DmaSpi0, SPIClass, SPI> *m_spiDma = nullptr;
@@ -137,8 +137,6 @@ private:
 	DmaSpi::Transfer *m_rxTransfer;
 
 	void m_setSpiCmdAddr(int command, size_t address, uint8_t *dest);
-//	RingBuffer<DmaSpi::Transfer> m_txFifo(MAX_DMA_XFERS);
-//	RingBuffer<DmaSpi::Transfer> m_rxFifo(MAX_DMA_XFERS);
 };
 
 

src/LibBasicFunctions.cpp

@@ -119,11 +119,14 @@ audio_block_t* AudioDelay::addBlock(audio_block_t *block)
 //				srcPtr--;
 //			}
 
-			int16_t *srcPtr = block->data;
-			for (int i=0; i<AUDIO_BLOCK_SAMPLES; i++) {
-				m_slot->writeAdvance16(*srcPtr);
-				srcPtr++;
-			}
+		    m_slot->writeAdvance16(block->data, AUDIO_BLOCK_SAMPLES);
+
+		    // Code below worked
+//			int16_t *srcPtr = block->data;
+//			for (int i=0; i<AUDIO_BLOCK_SAMPLES; i++) {
+//				m_slot->writeAdvance16(*srcPtr);
+//				srcPtr++;
+//			}
 
 		}
 		blockToRelease =  block;
@@ -210,11 +213,15 @@ bool AudioDelay::getSamples(audio_block_t *dest, size_t offset, size_t numSample
 //				destPtr--;
 //			}
 
-			int16_t *destPtr = dest->data;
-			for (int i=0; i<AUDIO_BLOCK_SAMPLES; i++) {
-				*destPtr = m_slot->readAdvance16();
-				destPtr++;
-			}
+			m_slot->readAdvance16(AUDIO_BLOCK_SAMPLES);
+
+//			// Code below worked
+//			int16_t *destPtr = dest->data;
+//			for (int i=0; i<AUDIO_BLOCK_SAMPLES; i++) {
+//				*destPtr = m_slot->readAdvance16();
+//				destPtr++;
+//			}
+
 			return true;
 		} else {
 			// numSampmles is > than total slot size
@@ -225,6 +232,11 @@ bool AudioDelay::getSamples(audio_block_t *dest, size_t offset, size_t numSample
 
 }
 
+void AudioDelay::readDmaBufferContents(audio_block_t *dest, size_t numSamples, size_t bufferOffset)
+{
+    m_slot->readDmaBufferContents(reinterpret_cast<uint8_t*>(dest->data), sizeof(int16_t)*numSamples, sizeof(int16_t)*bufferOffset);
+}
+
 ////////////////////////////////////////////////////
 // IirBiQuadFilter
 ////////////////////////////////////////////////////

src/LibBasicFunctions.h

@@ -109,7 +109,7 @@ public:
 
     /// Construct an audio buffer using a slot configured with the BAGuitar::ExternalSramManager
     /// @param slot a pointer to the slot representing the memory you wish to use for the buffer.
-    AudioDelay(ExtMemSlot *slot);
+    AudioDelay(ExtMemSlot *slot, bool useDma=true);
 
     ~AudioDelay();
 
@@ -140,6 +140,8 @@ public:
     /// @returns pointer to the underlying ExtMemSlot.
     ExtMemSlot *getSlot() const { return m_slot; }
 
+    void readDmaBufferContents(audio_block_t *dest, size_t numSamples = AUDIO_BLOCK_SAMPLES, size_t bufferOffset = 0);
+
     RingBuffer<audio_block_t*> *getRingBuffer() const { return m_ringBuffer; }
 
 private:

src/LibMemoryManagement.cpp

@@ -108,6 +108,28 @@ uint16_t ExtMemSlot::readAdvance16()
 	return val;
 }
 
+bool ExtMemSlot::readAdvance16(int16_t *dest=nullptr, size_t numWords)
+{
+    if (!m_valid) { return false; }
+    size_t numBytes = sizeof(int16_t)*numWords;
+
+    if (m_currentRdPosition + numBytes-1 <= m_end) {
+        // entire block fits in memory slot without wrapping
+        m_spi->read16(m_currentWrPosition, reinterpret_cast<uint16_t*>(dest), numWords); // cast audio data to uint.
+        m_currentRdPosition += numBytes;
+
+    } else {
+        // this read will wrap the memory slot
+        size_t rdBytes = m_end - m_currentRdPosition + 1;
+        size_t rdDataNum = rdBytes >> 1; // divide by two to get the number of data
+        m_spi->read16(m_currentRdPosition, reinterpret_cast<uint16_t*>(dest), rdDataNum);
+        size_t remainingData = numWords - rdDataNum;
+        m_spi->read16(m_start, reinterpret_cast<uint16_t*>(dest + rdDataNum), remainingData); // write remaining bytes are start
+        m_currentRdPosition = m_start + (remainingData*sizeof(int16_t));
+    }
+    return true;
+}
+
 
 bool ExtMemSlot::writeAdvance16(int16_t *src, size_t numWords)
 {
@@ -153,6 +175,11 @@ bool ExtMemSlot::zeroAdvance16(size_t numWords)
 	return true;
 }
 
+void ExtMemSlot::readDmaBufferContents(uint8_t *dest, size_t numBytes, size_t bufferOffset = 0)
+{
+    m_spi->readBufferContents(dest, numBytes, bufferOffset);
+}
+
 
 bool ExtMemSlot::writeAdvance16(int16_t data)
 {
@@ -229,14 +256,14 @@ size_t ExternalSramManager::availableMemory(BAGuitar::MemSelect mem)
 	return m_memConfig[mem].totalAvailable;
 }
 
-bool ExternalSramManager::requestMemory(ExtMemSlot *slot, float delayMilliseconds, BAGuitar::MemSelect mem)
+bool ExternalSramManager::requestMemory(ExtMemSlot *slot, float delayMilliseconds, BAGuitar::MemSelect mem, bool useDma)
 {
 	// convert the time to numer of samples
 	size_t delayLengthInt = (size_t)((delayMilliseconds*(AUDIO_SAMPLE_RATE_EXACT/1000.0f))+0.5f);
-	return requestMemory(slot, delayLengthInt * sizeof(int16_t), mem);
+	return requestMemory(slot, delayLengthInt * sizeof(int16_t), mem, useDma);
 }
 
-bool ExternalSramManager::requestMemory(ExtMemSlot *slot, size_t sizeBytes, BAGuitar::MemSelect mem)
+bool ExternalSramManager::requestMemory(ExtMemSlot *slot, size_t sizeBytes, BAGuitar::MemSelect mem, bool useDma)
 {
 
 	if (m_memConfig[mem].totalAvailable >= sizeBytes) {
@@ -249,7 +276,11 @@ bool ExternalSramManager::requestMemory(ExtMemSlot *slot, size_t sizeBytes, BAGu
 		slot->m_size = sizeBytes;
 
 		if (!m_memConfig[mem].m_spi) {
+		    if (useDma) {
+		        m_memConfig[mem].m_spi = new BAGuitar::BASpiMemoryDma(static_cast<BAGuitar::SpiDeviceId>(mem));
+		    } else {
 		        m_memConfig[mem].m_spi = new BAGuitar::BASpiMemory(static_cast<BAGuitar::SpiDeviceId>(mem));
+		    }
 			if (!m_memConfig[mem].m_spi) {
 				Serial.println("requestMemory: new failed! m_spi is a nullptr");
 			} else {
@@ -264,6 +295,7 @@ bool ExternalSramManager::requestMemory(ExtMemSlot *slot, size_t sizeBytes, BAGu
 		slot->m_valid = true;
 		if (!slot->isEnabled()) { slot->enable(); }
 		slot->clear();
+		slot->m_useDma = useDma;
 		return true;
 	} else {
 		// there is not enough memory available for the request

src/LibMemoryManagement.h

@@ -104,6 +104,14 @@ public:
 	/// @returns the next 16-bit data word in memory
 	uint16_t readAdvance16();
 
+
+	/// Read the next block of numWords during circular operation
+	/// @details, dest is ignored when using DMA
+	/// @param dest pointer to the destination of the read.
+	/// @param numWords number of 16-bit words to transfer
+	/// @returns true on success, else false on error
+	bool readAdvance16(int16_t *dest=nullptr, size_t numWords);
+
 	/// Write a block of 16-bit data from the specified location in circular operation
 	/// @param src pointer to the start of the block of data to write to memory
 	/// @param numWords number of 16-bit words to transfer
@@ -120,6 +128,7 @@ public:
 	/// @returns true on success, else false on error
 	bool zeroAdvance16(size_t numWords);
 
+	void readDmaBufferContents(uint8_t *dest, size_t numBytes, size_t bufferOffset = 0);
 
 	/// Get the size of the memory slot
 	/// @returns size of the slot in bytes
@@ -133,6 +142,8 @@ public:
 	/// @returns true if enabled, false if not enabled
 	bool isEnabled() const;
 
+	bool isUseDma() const { return m_useDma; }
+
 	/// DEBUG USE: prints out the slot member variables
 	void printStatus(void) const;
 
@@ -144,6 +155,7 @@ private:
 	size_t m_currentWrPosition = 0; ///< current write pointer for circular operation
 	size_t m_currentRdPosition = 0; ///< current read pointer for circular operation
 	size_t m_size = 0;              ///< size of this slot in bytes
+	bool   m_useDma = false;        ///< when TRUE, BASpiMemoryDMA will be used.
 	SpiDeviceId m_spiId;            ///< the SPI Device ID
 	BASpiMemory *m_spi = nullptr;   ///< pointer to an instance of the BASpiMemory interface class
 };
@@ -175,14 +187,14 @@ public:
 	/// @param delayMilliseconds request the amount of memory based on required time for audio samples, rather than number of bytes.
 	/// @param mem specify which external memory to allocate from
 	/// @returns true on success, otherwise false on error
-	bool requestMemory(ExtMemSlot *slot, float delayMilliseconds, BAGuitar::MemSelect mem = BAGuitar::MemSelect::MEM0);
+	bool requestMemory(ExtMemSlot *slot, float delayMilliseconds, BAGuitar::MemSelect mem = BAGuitar::MemSelect::MEM0, bool useDma = true);
 
 	/// Request memory be allocated for the provided slot
 	/// @param slot a pointer to the global slot object to which memory will be allocated
 	/// @param sizeBytes request the amount of memory in bytes to request
 	/// @param mem specify which external memory to allocate from
 	/// @returns true on success, otherwise false on error
-	bool requestMemory(ExtMemSlot *slot, size_t sizeBytes, BAGuitar::MemSelect mem = BAGuitar::MemSelect::MEM0);
+	bool requestMemory(ExtMemSlot *slot, size_t sizeBytes, BAGuitar::MemSelect mem = BAGuitar::MemSelect::MEM0, bool useDma = true);
 
 private:
 	static bool m_configured; ///< there should only be one instance of ExternalSramManager in the whole project