Diff: main.cpp

Revision:

2:913fc12a42a7

Parent:

1:ba7e525074f9

--- a/main.cpp	Thu Sep 08 11:13:51 2016 +0000
+++ b/main.cpp	Wed Sep 21 09:57:41 2016 +0000
@@ -4,11 +4,22 @@
 AnalogIn sensor(A2);
 
 int main() {
-    float temparature;
-    pc.printf("\nBD1020HFV Temperature sensor test program.\n");
+    float temperature1;
+    float temperature2;
+    pc.printf("\n\r");
+    pc.printf("BD1020HFV Temperature sensor test program.\n\r");
+    pc.printf("All values are approximates based on specification graph.\n\r");
+    pc.printf("Formula values should be calibrated before use.\n\r");
     while(1) {
-        temparature = -(1000 * (sensor * 3.3f) - 1546) / 8.2;
-        pc.printf("Temperature=%5.3f\r\n", temparature);
-        wait(0.4);
+        //Input voltage 0-3.3V == 0.0-1.0f
+        //-40'C == 1.87V
+        //  0'C == 1.546V
+        //192'C == 0V (out of scale)
+        //1.87V / 232'C = 0.008060V/'C
+        
+        temperature1 = -(1000 * (sensor * 3.3f) - 1546) / 8.2;
+        temperature2 = 192 - ( sensor * 3.3f / 0.008060 );
+        pc.printf("Temperature, formula1=%5.3f, formula2=%5.3f\r\n", temperature1, temperature2);
+        wait(1);
     }
 }