Changed to interrupt driven design

firmware/pid_playground/pid_playground.ino

@@ -4,6 +4,7 @@
 #include <ad7124_registers.hpp>
 #include <spi_selecta.hpp>
 #include <temp_table.hpp>
+#include <DueTimer.h>
 
 #define SPIRATE 84000000/32
 
@@ -55,9 +56,20 @@ void update_pid(double error, double* pid, const double* kpid, double& output){
   }  
 }
 
-/*Timekeeping*/
-unsigned long t0;
-unsigned long t1;
+/*Set up Timer Interrupt Infrastructure*/
+volatile bool printRq = false;
+const long printRqPeriod = 750000; //print every 750ms
+volatile bool pidUpdRq = false;
+const long pidUpdRqPeriod = 750000; //update pid every 750ms
+
+void handlerPrint(){
+  printRq = true; //set print request flag
+}
+
+void handlerPid(){
+  pidUpdRq = true; //set pid update request flag
+}
+
 
 /*Printing Buffer*/
 char printBuf[256];
@@ -136,8 +148,10 @@ void setup() {
       
   Spi_selecta::deselect_device();
   
-  t0 = micros();
-  t1 = micros();
+  /*Start Interrupt Timers*/
+  Timer.getAvailable().attachInterrupt(handlerPid).start(pidUpdRqPeriod);
+  delay(350); //delay the two timers by roughly half a period to balance load
+  Timer.getAvailable().attachInterrupt(handlerPrint).start(printRqPeriod);
 }
 
 void loop() {
@@ -156,7 +170,8 @@ void loop() {
     double current_temperature = data_to_temperature(adc1_data);
 
     //Update PID
-    if(micros() > t0 + 750000){ //This only runs every 750ms 
+    if(pidUpdRq){
+      pidUpdRq = false; //clear request flag
       pid_output = 0.;
       update_pid(target_temperature - current_temperature, pid_arr, kpid_arr, pid_output);
       //Update PWM Output
@@ -164,43 +179,10 @@ void loop() {
         Ltc6992::set_level(pid_output);
         //Ltc6992::set_level(0.42);
       }
-      t0 = micros();
     }
   }
     Spi_selecta::deselect_device();
 
-    
-  /*
-  Spi_selecta::select_device(&adc_2);
-  if(adc_2.data_available()){
-    uint32_t status_channel1 = adc_2.read_register(REG_Status, 1);
-    adc2_data = adc_2.get_data();
-    uint32_t status_channel2 = adc_2.read_register(REG_Status, 1);
-    uint32_t adc2_data_backup = adc2_data;
-    unsigned channel = static_cast<unsigned>(adc2_data & 0x000000FF);
-    adc2_data = ((adc2_data >> 8) & 0x00FFFFFF);
-    if(channel == (channel & 3)){ //channel must be an element of {0, 1, 2, 3}
-      adc2_temps[channel] = data_to_temperature(adc2_data);
-      Serial.print("Valid Channel: ");
-      Serial.print(channel);
-      Serial.print(" (");
-      Serial.print(status_channel1, HEX);
-      Serial.print(", ");
-      Serial.print(status_channel2, HEX);
-      Serial.print("), Data: 0x");
-      Serial.print(adc2_data_backup, HEX);
-      Serial.print("\n");
-    }
-    else{//something's fishy
-      Serial.print("Erroneous Channel: ");
-      Serial.print(channel);
-      Serial.print(", Data: 0x");
-      Serial.print(adc2_data_backup, HEX);
-      Serial.print("\n");
-    }
-  }
-  Spi_selecta::deselect_device();
-  */
 
   Spi_selecta::select_device(&adc_2);
   if(adc_2.data_available()){
@@ -219,23 +201,14 @@ void loop() {
     if(status_channel1 < 4){
       adc2_temps[status_channel1] = data_to_temperature(adc2_data);
     }
-    /*
-    Serial.print("Valid Channel: ");
-    Serial.print(status_channel1, HEX);
-    Serial.print(", Data: 0x");
-    Serial.print(adc2_data_backup, HEX);
-    Serial.print(", Error: ");
-    Serial.print(error, HEX);
-    Serial.print("\n");
-    */
   }
   Spi_selecta::deselect_device();
   
-  if(micros() > t1 + 750100){ /*print every 750ms*/
-    /*Format: T_loop T_ool_1 T_ool_2 T_ool_3 PID*/
+  if(printRq){
+    printRq = false;
+    /*Format: T_loop T_ool_1 T_ool_2 T_ool_3 PID P I D*/
     sprintf(printBuf, "Tloop:%f,Tool1:%f,Tool2:%f,Tool3:%f,Tool4:%f,PID:%f,P:%f,I:%f,D:%f\n", data_to_temperature(adc1_data), adc2_temps[0], adc2_temps[1], adc2_temps[2], adc2_temps[3], pid_output, pid_arr[0], pid_arr[1], pid_arr[2]);
     Serial.print(printBuf);
-    t1 = micros();
   }
   
 }