Seeedstudio Arch Examples : Temperature sensing using thermistor and AnalogIn interface.

Dependencies:   mbed

Fork of Arch_GPIO_Ex4 by Visweswara R

Revision:
6:914bd412ceda
Parent:
5:d035275d4c21
--- a/main.cpp	Mon Oct 07 13:10:03 2013 +0000
+++ b/main.cpp	Tue Oct 08 08:53:33 2013 +0000
@@ -1,5 +1,4 @@
 #include "mbed.h"
-#include "USBSerial.h"
 
 AnalogIn thermistor(P0_11);   /* Thermistor output connected to P0_11 */
 
@@ -15,7 +14,7 @@
         a = thermistor.read_u16(); /* Read analog value */
         
         /* Calculate the resistance of the thermistor from analog votage read. */
-        resistance= (float) 10000.0 * (1.0 - (a / 65536.0 ));
+        resistance= (float) 10000.0 * ((65536.0 / a) - 1.0);
         
         /* Convert the resistance to temperature using Steinhart's Hart equation */
         temperature=(1/((log(resistance/5000.0)/beta) + (1.0/298.15)))-273.15;