Diff: main.cpp

Revision:

0:cd3e218305bb

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Aug 06 13:03:00 2014 +0000
@@ -0,0 +1,56 @@
+/*
+ This program read temperature using two LM35 
+ sensors on A0 and A1 analog inputs and displays 
+ average temperature using serial
+ Also, if the temp is in the range (18,22) C then 
+ the green led is on, if the temp is in the range 
+ (16,18) and (22,24) C the blue led is on, else 
+ red led will be on.
+ You can see the connection diagram on my blog
+ sdizdarevic.com soon
+*/
+ 
+
+#include "mbed.h"
+DigitalOut red(LED_RED);                 // Red led
+DigitalOut blue(LED_BLUE); //blue led
+DigitalOut green(LED_GREEN); // green LED
+AnalogIn T1(PTB2); //  temperature  sensor T1 on A0
+AnalogIn T2(PTB3); // temperature  sensor T2 on A1
+float T; // average temperature
+float tempF; //average temperature in Fahrenheit
+float K=3.3*100; // scaling coefficient for calculating 
+ // analog value to temperature
+ 
+ Serial pc(USBTX,USBRX); // print temperature on console (eg. Putty)
+ 
+ 
+int main() {
+ pc.printf("LM35 temperature sensor\n");
+
+ while(1) {
+ red=0;//red=0;
+ blue=0; //blue=0;
+ green=0; //green=0;
+ T=(T1+T1)/2.*K; // average temperature value in Celsius (C)
+ 
+  
+tempF=(9.0*T)/5.0 + 32.0; //average temperature value in fahrenheit (F)
+
+ 
+ 
+ wait(0.2f); //wait a little
+ pc.printf("Temperature (in Celsius) is %4.2f \r\n",T);
+ 
+ 
+ wait(0.2f); //wait a little
+ pc.printf("Temperature (in Fahrenheit) is %4.2f \r\n",tempF);
+ 
+ 
+ if ( T>=18 && T<=22 ) green=1;
+ else if ((T>=16 && T<18)||(T>22 && T<=24)) blue=1;
+ else red=1;
+ wait(0.2);
+ 
+ }
+}
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