updated ADC SPI code

chp08/spi/adc_example/ADCmulti.cpp

@@ -0,0 +1,42 @@
+/* Using an SPI ADC (e.g., the MCP3008)
+* Written by Derek Molloy for the book "Exploring BeagleBone: Tools and
+* Techniques for Building with Embedded Linux" by John Wiley & Sons, 2014
+* ISBN 9781118935125. Please see the file README.md in the repository root
+* directory for copyright and GNU GPLv3 license information.            */
+
+#include <iostream>
+#include <sstream>
+#include "bus/SPIDevice.h"
+#define SAMPLES 200
+
+using namespace std;
+using namespace exploringBB;
+
+short combineValues(unsigned char upper, unsigned char lower){
+   return ((short)upper<<8)|(short)lower;
+}
+
+int main(){
+//   cout << "Starting EBB SPI ADC Multi Example" << endl;
+   SPIDevice *busDevice = new SPIDevice(1,0); //Using second SPI bus (both loaded)
+   busDevice->setSpeed(4000000);      // Have access to SPI Device object
+   busDevice->setMode(SPIDevice::MODE0);
+
+   unsigned char send[3], receive[3];
+   int samples[SAMPLES];
+
+   send[0] = 0b00000001; // The Start Bit followed
+   // Set the SGL/Diff and D mode -- e.g., 1000 means single ended CH0 value
+   send[1] = 0b10000000; // The MSB is the Single/Diff bit and it is followed by 000 for CH0
+   send[2] = 0;          // This byte doesn't need to be set, just for a clear display
+
+   for(int i=0; i<SAMPLES; i++){
+   	busDevice->transfer(send, receive, 3);
+        samples[i]=combineValues(receive[1]&0b00000011, receive[2]);
+   }
+//   cout << "The samples that were captured are:" << endl;
+   for(int i=0; i<SAMPLES; i++){
+        cout << i << " " << samples[i] << endl;
+   }
+//   cout << "\nEnd of EBB SPI ADC Example" << endl;
+}

chp08/spi/adc_example/ADCmulti2.cpp

@@ -0,0 +1,39 @@
+/* Using an SPI ADC (e.g., the MCP3008)
+* Written by Derek Molloy for the book "Exploring BeagleBone: Tools and
+* Techniques for Building with Embedded Linux" by John Wiley & Sons, 2014
+* ISBN 9781118935125. Please see the file README.md in the repository root
+* directory for copyright and GNU GPLv3 license information.            */
+
+#include <iostream>
+#include <sstream>
+#include "bus/SPIDevice.h"
+#define SAMPLES 20000
+
+using namespace std;
+using namespace exploringBB;
+
+short combineValues(unsigned char upper, unsigned char lower){
+   return ((short)upper<<8)|(short)lower;
+}
+
+int main(){
+   SPIDevice *busDevice = new SPIDevice(1,0); //Using second SPI bus (both loaded)
+   busDevice->setSpeed(4000000);      // Have access to SPI Device object
+   busDevice->setMode(SPIDevice::MODE0);
+
+   unsigned char send[3], receive[3];
+   int samples[SAMPLES];
+
+   send[0] = 0b00000001; // The Start Bit followed
+   // Set the SGL/Diff and D mode -- e.g., 1000 means single ended CH0 value
+   send[1] = 0b10000000; // The MSB is the Single/Diff bit and it is followed by 000 for CH0
+   send[2] = 0;          // This byte doesn't need to be set, just for a clear display
+
+   for(int i=0; i<SAMPLES; i++){
+   	busDevice->transfer(send, receive, 3);
+        samples[i] = (short((receive[1]&0b00000011))<<8)|(short(receive[2]));
+   }
+   for(int i=0; i<SAMPLES; i++){
+        cout << i << " " << samples[i] << endl;
+   }
+}

chp08/spi/adc_example/build

@@ -1,2 +1,4 @@
 #!/bin/bash
+g++ -o ADCmulti ADCmulti.cpp bus/SPIDevice.cpp bus/BusDevice.cpp
+g++ -O3 -o ADCmulti2 ADCmulti2.cpp bus/SPIDevice.cpp bus/BusDevice.cpp
 g++ -o ADCExample ADCExample.cpp bus/SPIDevice.cpp bus/BusDevice.cpp