Diff: main.cpp

Revision:

0:7d24851a0521

Child:

1:748e07bbe96e

diff -r 000000000000 -r 7d24851a0521 main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri Dec 02 17:11:13 2011 +0000
@@ -0,0 +1,115 @@
+#include "mbed.h"
+
+#define NUM_SAMPLES 500000 // size of sample series
+#define SAMPLE_BLOCKS 5
+
+Timer t;
+
+Serial pc(USBTX,USBRX);
+
+AnalogIn ain(p17);
+
+// initialise error counters
+int num_4;
+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_4 = 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;
+
+
+// Take the average over 500,000 samples
+// This is because the bias to 1.65v has a tolerance
+    float AVERAGE = 0.5;
+
+    pc.printf("Taking an average over %d samples\n",NUM_SAMPLES);
+    while (num_samples < NUM_SAMPLES) {
+        float r = ain.read();
+
+        if ((r > 0.45) && (r < 0.55)) {
+            AVERAGE += r;
+            num_samples++;
+        }
+    }
+    
+    AVERAGE /= NUM_SAMPLES;
+    
+    num_samples = 0;
+    pc.printf("Average = %f\n",AVERAGE);
+
+
+// Now start sampling series of 500,000
+// acculumating the errors seen in each range
+    pc.printf("Profiling %d samples\n",SAMPLE_BLOCKS*NUM_SAMPLES);
+    for (int j=0; j < SAMPLE_BLOCKS ; j++) {
+
+        t.reset();
+        t.start();
+        
+        for (int i = 0; i < NUM_SAMPLES ; i++) {
+            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
+            } else if (a > (AVERAGE + 0.0009)) {
+                num_4++;    // > 8 lsb
+            }
+
+            num_samples++;
+        }
+        t.stop();
+        
+        // Every 500,000 print the results
+        pc.printf("%d\t",num_samples);
+        pc.printf("%d\t",num_4);
+        pc.printf("%d\t",num_8);
+        pc.printf("%d\t",num_16);
+        pc.printf("%d\t",num_32);
+        pc.printf("%d\t",num_64);
+        pc.printf("%d\t",num_128);
+        pc.printf("%d\t",num_256);
+        pc.printf("%d\t",num_512);
+        pc.printf("%d\t",num_1024);
+        pc.printf("%d\t",num_2048);
+        pc.printf("%f\n",t.read());
+    }
+    
+    pc.printf("==== Test Complete ====\n");
+}