main.cpp

00001 
00002 /*
00003 ****************************************************************************************************
00004 Wireless temperature transmitter with ER400TRS wireless transceiver and MCP9700 temperature sensor.
00005 433 MHz transceiver.  180 bytes of data. 19200 Baud.
00006 MCP9700 temperature sensor: -40ºC - +125ºC.
00007 
00008 Wiring MCP9700:
00009 p1: +3V3. p2(Vout): mBed's p15. p3: ground.
00010 
00011 Wiring ER400TRS:
00012 p1: antenna(17 cm). p2,p7(Host Ready Input) and p9: ground.
00013 p6(Serial Data In): mBed's p9(tx). p8: Vcc = +5 V.
00014 
00015 Author: Lluis Nadal. August 2011.
00016 *****************************************************************************************************
00017 */
00018 
00019 #include "mbed.h"
00020 //#include "TextLCD.h" . Optional
00021 
00022 // LCD optional
00023 // Define LCD connections.
00024 //TextLCD lcd(p24, p26, p27, p28, p29, p30); // rs, e, d4, d5, d6, d7
00025 
00026 Serial pc(USBTX, USBRX); // tx, rx
00027 Serial transmitter(p9, p10);  // tx, rx
00028 AnalogIn temp(p15);
00029 
00030 char s1[10];
00031 char s2[10];
00032 float T;
00033 
00034 
00035 float tempRead() {
00036 
00037     float Ta = 0.0;
00038     float t = temp.read();           // read the analog data
00039     Ta = ((t * 3.3) - 0.5)/ 0.01;
00040 
00041     return Ta;                      // return the temp
00042 }
00043 
00044 
00045 int main() {
00046 
00047     //lcd.cls();
00048     pc.printf("Init: 19200 Baud\r\n\r\n");
00049     //lcd.printf("Init: 19200 Baud");
00050     wait(2);
00051     transmitter.baud(19200);
00052 
00053     while (1) {
00054         T = tempRead();
00055         sprintf(s1, "%.1f", T);
00056         sprintf(s2, "%.1f\n", T); //scanf in the receiver needs a whitespace or newline character
00057         transmitter.printf(s2);
00058         //lcd.cls();
00059         sprintf(s1,"%s C", s1);
00060         pc.printf(" %s\r\n", s1);
00061         //lcd.printf(s1);
00062 
00063         wait(2);
00064     }
00065 }