Save off DMATransfer library work.

Author: xC0000005

libraries/DMA/kewords.txt

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+#######################################
+# Syntax Coloring Map For DMA
+#######################################
+
+#######################################
+# Datatypes (KEYWORD1)
+#######################################
+
+DMA	KEYWORD1
+DMA1	KEYWORD1
+DMA2	KEYWORD2
+
+#######################################
+# Methods and Functions (KEYWORD2)
+#######################################
+
+start	KEYWORD2
+
+#######################################
+# Constants (LITERAL1)
+#######################################

libraries/DMA/library.properties

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+name=DMA
+version=0.0.1
+author=J.C. Nelson
+sentence=Enables Direct Memory Access Transfers.
+paragraph=This library allows use of Direct Memory Access (DMA) for transfer between memory locations, to and from peripherals.
+category=Data Transfers
+architectures=stm32

libraries/DMA/src/DMATransfer.cpp

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+#include <dma.h>
+
+/**
+  * @brief  Prepares for DMA Transfer by enabling clocks
+  *         and storing the settings in the slots
+  * @param  settings : dma transfer settings
+  * @retval None
+  */
+void DMATransferClass::prepare(dmatransfer_t *settings) {
+  if (!_prepared) {
+    __HAL_RCC_DMA1_CLK_ENABLE();
+
+    _transfer_settings.dma_settings.Init.Direction = DMA_MEMORY_TO_PERIPH;
+    _transfer_settings.dma_settings.Init.PeriphInc = DMA_PINC_DISABLE;
+    _transfer_settings.dma_settings.Init.MemInc = DMA_MINC_DISABLE;
+    _transfer_settings.dma_settings.Init.PeriphDataAlignment = DMA_PDATAALIGN_WORD;
+    _transfer_settings.dma_settings.Init.MemDataAlignment = DMA_MDATAALIGN_WORD;
+    _transfer_settings.dma_settings.Init.Mode = settings.circular ? DMA_CIRCULAR : DMA_NORMAL;
+    _transfer_settings.dma_settings.Init.Priority = DMA_PRIORITY_VERY_HIGH;
+    _transfer_settings.dma_settings.Instance = settings.channel_stream;
+
+    // Perform HAL Initialization first.
+    HAL_DMA_Init(&dmaUpdate);
+
+    // Call dma prepare
+    prepare_dma(&_transfer_settings);
+  }
+}
+
+/**
+  * @brief  Begin the DMA transfer
+  * @retval None
+  */
+void DMATransferClass::begin(int bytes_to_transfer) {
+  if (!prepared) {
+    // call dma prepare
+    prepare_dma(&_transfer_settings);
+  }
+
+  // Reset flags so it starts over
+  __HAL_DMA_CLEAR_FLAG(&_transfer_settings, DMA_FLAG_TC2 | DMA_FLAG_HT2 | DMA_FLAG_TE2);
+
+  // Set size to transfer
+  _transfer_settings.dma_settings.Instance->CNDTR = bytes_to_transfer;
+
+  // and enable it
+  __HAL_DMA_ENABLE(&_transfer_settings.dma_settings);
+}
+
+/**
+  * @brief  End the DMA transfer
+  * @retval None
+  */
+void DMATransferClass::end() {
+
+  __HAL_DMA_DISABLE(&_transfer_settings);
+
+  if (_prepared) {
+    end_dma(&_transfer_settings);
+    _prepared = false;
+  }
+}

libraries/DMA/src/DMATransfer.h

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+#ifndef __DMATRANSFER_H__
+#define __DMATRANSFER_H__
+
+#include "Arduino.h"
+
+typedef struct dmatransfer_s dmatransfer_t;
+
+#if defined(STM32F2xx) || defined(STM32F4xx) || defined(STM32F7xx)
+  typedef DMA_Stream_TypeDef DMA_CS_Selection;
+#else
+  typedef DMA_Channel_TypeDef DMA_CS_Selection;
+#endif
+
+
+struct dmatransfer_s {
+    /*  Keep this the first member so casting back and forth is easy
+     */
+  DMA_HandleTypeDef *dma_settings;
+  DMA_CS_Selection channel_stream;
+  boolean circular;
+  void (*transferComplete)(DMA_HandleTypeDef *);
+  void (*transferHalfComplete)(DMA_HandleTypeDef *);
+  void (*transferError)(DMA_HandleTypeDef *);
+};
+
+class DMATransferClass {
+
+  public:
+    void prepare(dmatransfer_t *settings);
+    void begin(int bytes_to_transfer);
+    void end();
+  private:
+    bool _prepared;
+    dmatransfer_t _transfer_settings;
+};
+
+
+#endif /* __DMATRANSFER_H__ */