Diff: temp.cpp

Revision:

1:924bead61d21

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/temp.cpp	Tue Jun 27 20:54:33 2017 +0000
@@ -0,0 +1,104 @@
+#include "temp.h"
+#include "TextLCD.h"
+#include <cmath>
+
+AnalogIn temp(p19);
+DigitalOut htr(p27);
+extern Serial pc;
+extern TextLCD lcd;
+extern bool htr_suspension, rfl_flag;
+extern float air_temp;
+
+float calc_temp() {
+    float rt, t, voltage = 3.3 * temp.read();;
+    rt = R1*voltage/(3.3-voltage);
+    t = 1 / (K0 + K1 * log(rt) + K2 * pow(log(rt),3.0f));
+    return t - 273.15;
+}
+
+float take_air_temp() {
+    pc.printf("Going to take air temperature. Please make sure that the sensor is in the air and connected to the controller\n");
+    pc.printf("If you are ready, please press switch 3\n");
+    //pc.printf("rfl_flag = %s\n", rfl_flag ? "true":"false");
+    while (!rfl_flag) {wait(0.1);}        //Wait until switch 4 has been pressed
+    rfl_flag = false;
+    return calc_temp();
+}
+
+void print_temp(float temp) {
+    pc.printf("Temperature = %.3f\n", temp);
+    lcd.cls();
+    lcd.printf("Temp: %.3f\n", temp);
+}
+
+bool sensor_out_of_water_check(float cT) {
+    if (air_temp-ATB<cT && cT<air_temp+ATB) {                                   //sensor out of water
+        pc.printf("Temperature similar to air temperature. Highly likely that the sensor is out of the water\n");
+        pc.printf("Please check the temperature sensor position\n");
+        htr_suspension = true;                                                  //Suspend heater
+        pc.printf("For safety reasons, heater operation has been suspended. If everything is OK, resume operation by pressing switch 4\n");
+        return false;
+    }
+    return true;
+}
+
+bool connection_check(float cT) {
+    if (cT<LC) {                                                                //Connection lost
+        pc.printf("Temperature extremely freezingly low! Highly likely that the temp sensor connection is lost\n");
+        pc.printf("Please check the temperature sensor connection\n");
+        htr_suspension = true;                                                  //Suspend heater
+        pc.printf("For safety reasons, heater operation has been suspended. If everything is OK, resume operation by pressing switch 4\n");
+        return false;
+    }
+    return true;
+}
+
+bool malfunction_check(float cT) {
+    if (cT<TMLL || cT>TMUL) {                                                   //Bizzare temps
+        pc.printf("Temperature sensor is giving bizzare temps\n");
+        pc.printf("Temperature sensor malfunction is higly likely! Please check the sensor\n");
+        htr_suspension = true;                                                  //Suspend heater
+        pc.printf("For safety reasons, heater operation has been suspended. If everything is OK, resume operation by pressing switch 4\n");
+        return false;
+    }
+    return true;
+}
+
+void heater_control(float cT) {
+    if (cT<=TSLL) {
+        if(!htr_suspension) {
+            htr=1;  pc.printf("Heater activated\n");
+            pc.printf("Expecting temperature to rise\n");
+        }
+        else { pc.printf("Heater operation is suspended! If you want to resume operation press switch 4\n");}
+    }
+    else if(cT>=TSUL) {
+        htr=0;
+        pc.printf("Heater deactivated\n");
+        pc.printf("Expecting temperature to fall\n");
+    }
+}
+
+bool temp_control(){
+    bool temp_state = true;                                                     //Assume normal temperature
+    float cT = calc_temp();                                                     //Calculate temperature
+    print_temp(cT);                                                             //Print temp to lcd and pc
+    temp_state = connection_check(cT);                                          //connection check
+    temp_state = malfunction_check(cT);                                         //Malfunction check
+    temp_state = sensor_out_of_water_check(cT);                                 //Sensor out of water check
+    heater_control(cT);                                                         //Heater control
+    wait(3);                                                                    //Introduce a 3" delay in order for the changes to have an effect
+    cT = calc_temp();                                                           //Calculate temperature again    
+    if (cT<TALL) {
+        temp_state = false;
+        pc.printf("Temperature really low! Heater must be activated!\n");
+        if(htr==1) pc.printf("Heater already activated so beaker is exposed to freezing conditions");
+    }
+    if (cT>TAUL) {
+        temp_state = false;
+        pc.printf("Temperature really high!\n");
+        if(htr==0) pc.printf("Heater already deactivated so beaker is exposed to an external heating source or heater is powered directly from the mains!\nPlease check heater connection!");
+    }
+    pc.printf("\n");
+    return temp_state;
+}
\ No newline at end of file