Diff: main.cpp

Revision:

0:62a007afbcbf

Child:

1:bdd134268a52

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Dec 01 16:37:07 2011 +0000
@@ -0,0 +1,130 @@
+#include "mbed.h"
+
+#define NUM_SAMPLES 500000
+
+DigitalOut myled(LED1);
+Serial pc(USBTX,USBRX);
+
+AnalogIn ain(p17);
+
+Timer t;
+
+int num_8;
+int num_16;
+int num_32;
+int num_64;
+int num_128;
+int num_256;
+int num_512;
+int num_1024;
+int num_2048;
+
+
+int main() {
+
+    pc.baud(115200);
+    
+    int num_samples = 0;
+
+    num_8 = 0;
+    num_16 = 0;
+    num_32 = 0;
+    num_64 = 0;
+    num_128 = 0;
+    num_256 = 0;
+    num_512 = 0;
+    num_1024 = 0;
+    num_2048 = 0;
+
+/*
+    while (1) {
+        pc.printf("%f\n",ain.read());
+//        wait(0.1);
+    }
+*/
+
+
+
+
+// do a calibration
+
+    float AVERAGE = 0.5;
+
+    // taking an average    
+    pc.printf("Taking an average over %d samples\n",NUM_SAMPLES);
+    while (num_samples < NUM_SAMPLES) {
+     float r = ain.read();
+     
+     if ((r > 0.49) && (r < 0.51)) {
+     AVERAGE = (AVERAGE + r) /2.0;
+     num_samples++;
+     }
+    
+    }
+    pc.printf("Average = %f\n",AVERAGE);
+
+        
+
+    pc.printf("Reading floats\n");
+    num_samples = 0;
+    t.reset();
+    t.start();
+    
+    while (num_samples < NUM_SAMPLES) {
+        float a = ain.read();
+
+
+        if (a > (AVERAGE + 0.5000)) 
+            {num_2048++;} // > 2048 lsb
+        else if (a > (AVERAGE + 0.2500)) 
+            {num_1024++;} // > 1024 lsb
+        else if (a > (AVERAGE + 0.0625)) 
+            {num_512++;} // > 512 lsb
+        else if (a > (AVERAGE + 0.0312)) 
+            {num_256++;} // > 256 lsb
+        else if (a > (AVERAGE + 0.0312)) 
+            {num_128++;} // > 128 lsb
+        else if (a > (AVERAGE + 0.0156)) 
+            {num_64++;} // > 64 lsb
+        else if (a > (AVERAGE + 0.0078)) 
+            {num_32++;} // > 32 lsb
+        else if (a > (AVERAGE + 0.0039)) 
+            {num_16++;} // > 16 lsb
+        else if (a > (AVERAGE + 0.0019)) 
+            {num_8++;} // > 8 lsb
+        
+        num_samples++;
+    }
+    
+    t.stop();
+    pc.printf("Time taken for %d samples was %fs\n",NUM_SAMPLES,t.read());
+    pc.printf("over 8 lsb = %d\n",num_8);
+    pc.printf("over 16 lsb = %d\n",num_16);
+    pc.printf("over 32 lsb = %d\n",num_32);
+    pc.printf("over 64 lsb = %d\n",num_64);
+    pc.printf("over 128 lsb = %d\n",num_128);
+    pc.printf("over 256 lsb = %d\n",num_256);
+    pc.printf("over 512 lsb = %d\n",num_512);
+    pc.printf("over 1024 lsb = %d\n",num_1024);
+    pc.printf("over 2048 lsb = %d\n",num_2048);
+
+
+
+
+
+/*
+    pc.printf("Reading _u16\n");
+    num_samples = 0;
+    t.reset();
+    t.start();
+    while (num_samples < NUM_SAMPLES) {
+        int a = ain.read_u16();
+        num_samples++;
+    }
+    t.stop();
+    pc.printf("Time taken for %d samples was %fs\n",NUM_SAMPLES,t.read());
+
+*/
+
+
+}