main.cpp

00001 /* Libraries */
00002 #include "mbed.h"
00003 #include "TextLCD.h"
00004 
00005 /* */
00006 #define DELAY_M 50              //Delay before Measuring Voltage at ADC-Pin (TempNow)
00007 #define TEMP_BASEGAIN 0.137931  //Temp which should equal 1mV - changed by TEMP_FACTOR
00008 #define TEMP_OFFSET 0           //Offset of Temperature
00009 #define CTRL_GAIN 10            //TempDifference to PWM-Value Gain
00010 #define TEMP_FACTOR 1.5         //TEMP_BASEGAIN * TEMP_FACTOR = TEMP_GAIN
00011 
00012 /*  */
00013 Ticker dispRefresh;
00014 TextLCD lcd (p18, p16, p11, p10, p9, p8); // rs, e, d4-d7
00015 DigitalOut db5(p10);    //Data Pin 5 on LCD, used for Initialization
00016 DigitalOut rw(p17);     //Read-Write Pin on LCD: LOW-->WRITE
00017 PwmOut pHeat(p26);      //Heater-Pin 
00018 AnalogIn adc(p20);      //ADC-Pin 10Bit
00019 PwmOut pSpeaker(p25);   //Piezo-Speaker Pin
00020 InterruptIn rotSw1(p35); //Pin 1 of Rotary Encoder
00021 DigitalIn rotSw2(p33);   //Pin 2 of Rotary Encoder
00022 InterruptIn rotSwB(p30);   //Button of Rotary Encoder
00023 DigitalOut tempCtrlLED(LED1);
00024 
00025 /* */
00026 float TempNow = 0;      //Current Temperature Reading
00027 float TempSet = 200;      //Set Temperature   
00028 float pwmVal = 0;       //PWM-Value for Heater-Pin
00029 float adcVal = 0;       //Value of ADC-Reading
00030 
00031 /* */
00032 void writeLCD();
00033 void init4BitLCD();
00034 void readTemp();
00035 void calcPWM();
00036 void RotEnc();
00037 void RotBut();
00038 
00039 int ticker = 500;
00040 Ticker t;
00041 void tick_1(){
00042     if(ticker > 0) ticker--;
00043 }
00044 
00045 int main() {
00046     //Initialize
00047     init4BitLCD();      //Set Display to 4 Bit-Mode
00048     rw = 0;             // Set Read/Write Pin to Write
00049     rotSw1.rise(&RotEnc);
00050     rotSwB.rise(&RotBut);
00051     pSpeaker.period_ms(2); //Set Speaker Frequency to 500Hz
00052     //pHeat = 0.1;   
00053     
00054     t.attach(&tick_1, 0.001);
00055     while(1) {
00056         readTemp();     //Read Temperature              - Done
00057         calcPWM();      //Calculate PWM-Value           - Done
00058         pHeat = pwmVal; //Write PWM-Value to Heater     - Done
00059         if(ticker == 0){
00060             writeLCD();     //Write To LCD                  - Done
00061             ticker = 500;
00062         }
00063         //Repeat
00064     }
00065 }
00066 
00067 void RotBut()
00068 {tempCtrlLED = !tempCtrlLED;
00069  if (pSpeaker == 0){pSpeaker = 0.5;}
00070  else {pSpeaker = 0;}}
00071  
00072 void RotEnc()
00073 {
00074     if (rotSw2 == 0){TempSet++;}
00075     else if (rotSw2 == 1){TempSet--;}
00076     wait_ms(1);
00077     }
00078 
00079 void calcPWM()
00080 {
00081     pwmVal = ((TempSet - TempNow) * CTRL_GAIN) / 255; //Calculate PWM-Val.
00082     if (pwmVal > 1) pwmVal = 1;
00083     else if (pwmVal < 0) pwmVal = 0;
00084     }
00085 
00086 void readTemp()
00087 {   pHeat = 0;      //Switching Off Heater || Thermoelement --> No VoltageSupply
00088     wait_ms(DELAY_M);   //Waiting for a bit|| Low-Pass Filter --> Ready State
00089     adcVal = adc.read();    //Read ADC
00090     TempNow = adcVal*3300*(TEMP_BASEGAIN * TEMP_FACTOR) + TEMP_OFFSET;   //Calculate current Temperature
00091     pHeat = pwmVal;     //Re-Activate Heater Pin
00092     }
00093 
00094 void writeLCD()
00095 {   char cHeat;
00096     if(pwmVal > 0.5){cHeat = 'H';}
00097     else{cHeat = ' ';}
00098     lcd.cls();
00099     lcd.printf("Set: %.0f C   %c\nNow: %.0f C", TempSet, cHeat, TempNow);}
00100     
00101 void init4BitLCD()
00102 {   db5 = 1; wait_ms(1); lcd.cls();}