Diff: main.cpp

Revision:

0:4d02779757de

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri May 06 18:52:40 2016 +0000
@@ -0,0 +1,84 @@
+/* 
+    Read analog channel from MCP3201 with SPI interface and send it to the serial interface.
+    Matlab can be used to evaluate the sampled wave.
+*/
+
+
+#include "mbed.h"
+
+#define VOLTAGE_SAMPLES         255
+
+// for samples serial dumping 
+int samples[255];
+
+#include "mcp3201.h"
+#include "VoltageRead.h"
+
+Serial pc(USBTX, USBRX); // tx, rx
+
+int main() 
+{
+    pc.baud(115200);
+    pc.printf("Ola Sr. Matlab!");
+    
+    while(1) 
+    {  
+        float rms_value=get_voltage_rms();
+        for(int i=0;i<VOLTAGE_SAMPLES;i++) pc.printf("%i\r\n", samples[i]);
+        //end of com
+        pc.printf(" ");
+        
+        //run Matlab script again to get new sample
+        char c = pc.getc();
+    }
+}
+
+/*
+s=serial('COM6','BAUD',115200,'Terminator',' ','InputBufferSize', 8096,'OutputBufferSize',1024);
+fopen(s);
+fprintf(s,'c','async');
+x=fscanf(s);
+y=str2num(x);
+
+ADC_OFFSET=floor(1.7*(4096/3.3));
+ADC_SCALE=(2110*sqrt(2))/4096; %Valor de Tensao no pino 3.3/4096
+VOLTAGE_SAMPLES=256;
+
+t=linspace(0,inv(60)*VOLTAGE_SAMPLES/256,VOLTAGE_SAMPLES-1);
+
+figure(1);
+subplot(2,1,1)
+%stem(y.*(3.3/4096),'x.'); grid;
+stem(y+ADC_OFFSET,'.'); grid;
+title('Sampled Wave from MCP3201');
+xlabel('Sample Number [0...255]');
+ylabel('Sampled Value [0...4095)');
+
+subplot(2,1,2)
+stem(y,'.','b'); grid;
+title('Offset Adjustment to RMS calculation');
+xlabel('Sample Number [0...255]');
+ylabel('Sampled Value [-2048...2047)');
+
+figure(2);
+stairs(t,y.*(ADC_SCALE)); grid;
+title('Reconstructed wave');
+xlabel('time [s]');
+ylabel('Voltage [Volts)');
+%hold on
+%plot(y.*(ADC_SCALE),'--');
+%hold off
+
+rms=sqrt(mean((y.^2)))*ADC_SCALE;
+disp('  Valor RMS')
+disp(rms)
+
+fclose(s);
+clear s;
+% sometimes the channel remains open, use this
+% fclose(instrfind)
+*/
+
+
+    
+