Diff: Codes/Capture.cpp

Revision:

0:c64e1194230b

Child:

1:917ca6b5d9d9

diff -r 000000000000 -r c64e1194230b Codes/Capture.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Codes/Capture.cpp	Wed Jul 09 21:16:23 2014 +0000
@@ -0,0 +1,85 @@
+/*
+ * Capture.h
+ *
+ *  Created on: 
+ *      Author: 
+ */
+#include "Capture.h"
+
+Semaphore Capture::m_CaptureSemaphore(1); //used to alert the capture thread about a ready capture 
+int Capture::m_BufferIndex;
+dmaLinkedListNode Capture::m_Nodes[2] __attribute__((section("AHBSRAM0"))); //this list holds the buffer configuration for the DMA peripheral
+unsigned short int Capture::m_AdcBuffers[2][NUMBER_OF_SAMPLES][NUMBER_OF_CHANNELS] __attribute__((section("AHBSRAM0")));
+
+//This function prepares the capture buffers and starts the DMA peripheral
+void Capture::Start()
+{
+    m_Nodes[0].destAddr = (unsigned int)m_AdcBuffers[0];// HERE GOES THE BUFFER ADDRESS(unsigned int)adval;
+    m_Nodes[0].sourceAddr = (unsigned int)&LPC_ADC->ADGDR;
+    m_Nodes[0].dmaControl = (NUMBER_OF_SAMPLES*NUMBER_OF_CHANNELS)| DMA_DST_WIDTH_HALFWORD | DMA_SRC_WIDTH_HALFWORD | DMA_DST_INCREMENT | DMA_TC_INT;
+    m_Nodes[0].nextNode = (unsigned int)&m_Nodes[1];
+
+    m_Nodes[1].destAddr = (unsigned int)m_AdcBuffers[1];// HERE GOES THE BUFFER ADDRESS(unsigned int)adval2;
+    m_Nodes[1].sourceAddr = (unsigned int)&LPC_ADC->ADGDR;
+    m_Nodes[1].dmaControl = (NUMBER_OF_SAMPLES*NUMBER_OF_CHANNELS)| DMA_DST_WIDTH_HALFWORD | DMA_SRC_WIDTH_HALFWORD | DMA_DST_INCREMENT | DMA_TC_INT;
+    m_Nodes[1].nextNode = (unsigned int)&m_Nodes[0];
+
+    m_BufferIndex=0;
+
+    while(!(LPC_ADC->ADDR0&(1U<<31)));  //waits the completion of the ADC Channel 0 capture - for synchronization purposes
+    while(!(LPC_ADC->ADDR0&(1U<<31)));  //waits the completion of the ADC Channel 0 capture - for synchronization purposes
+
+    setup_channel(&m_Nodes[0],0,DMA_PERIPHERAL_ADC,DMA_MEMORY);
+}
+
+//This function initializes the ADC and DMA peripherals
+void Capture::Initialize()
+{   
+    init_adc(Settings::get_FreqBase()*NUMBER_OF_SAMPLES*NUMBER_OF_CHANNELS);
+    select_channels(ADC_CH_0|ADC_CH_1|ADC_CH_2|ADC_CH_3|ADC_CH_4|ADC_CH_5);
+    LPC_ADC->ADCR |= ADC_MODE_BURST;
+
+    init_dma();
+    
+    Start();
+    
+    m_CaptureSemaphore.wait();
+}
+
+void Capture::Stop()
+{
+    m_CaptureSemaphore.release();   //release semaphore
+    stop_channel();
+}
+
+void Capture::Wait()
+{
+    m_CaptureSemaphore.wait(osWaitForever);
+}
+
+unsigned short int Capture::GetValue(int nsamples, int nchannel)
+{
+    return ADC_CONVERT(m_AdcBuffers[m_BufferIndex][nsamples][nchannel]);
+}
+
+void Capture::CopyBuffer(int channel, unsigned short int *dest)
+{
+    for(int i=0;i<Settings::get_Samples();i++)
+    {
+        dest[i] = GetValue(i,channel);
+    }
+}
+
+//DMA ISR signals the capture thread about the end of capture event
+extern "C" void DMA_IRQHandler(void)
+{
+    Capture::ISRHandler();
+}
+
+void Capture::ISRHandler()
+{
+    Capture::m_BufferIndex = (~Capture::m_BufferIndex)&1;
+
+    Capture::m_CaptureSemaphore.release();
+    LPC_GPDMA->DMACIntTCClear = 0xFF;
+}
\ No newline at end of file