 
   // Set up serial plotter
   plotter.Begin(); // start plotter
-  plotter.AddTimeGraph( "Reflow oven variables", 6000,//18000, // about 3 minutes
+  String headline = "Reflow oven (PID constants: P=";
+  headline += String(PID_Kp);
+  headline += " I=";
+  headline += String(PID_Ki);
+  headline += " D=";
+  headline += String(PID_Kd);
+  headline += ")";
+  plotter.AddTimeGraph(headline,
+                          18000, // about 3 minutes
                           "PID Setpoint (°C)", PID_setpoint,
                           "PID Input (°C)", PID_in,
                           "PID Output (%)", PID_out_percent,
                           "Oven state (on/off)", oven_is_on);
+
+ // Serial.begin(115200);
 
   // Configure PID controller
   control_PID.SetOutputLimits(0, pwm_window);

  digitalWrite(THERMISTOR_MOSFET, HIGH);
  double avg = (double) sum / count;

  double inp_voltage = avg * 1.1 / 1023; // Reference voltage = 1.1V,
                                         // maximum value = 1023 (10 bits)
  // voltage divider 1k over PT100 thermistor connected to 5V
  double R_PT100 = 1000./(5./inp_voltage-1);


 * timestamps, the temperature is interpolated linearly.
 */
const unsigned int tprofile_n = 5;
const unsigned long tprofile_times[] = {10000000, 20000, 30000, 50000, 60000};
const float tprofile_temps[] =         {80, 200, 235, 235,   0};
reflow_profile tprofile(tprofile_n, tprofile_times, tprofile_temps);

void plot_callback(void) {
  // plotting thread
  plotter.Plot();
  //Serial.println(PID_in);
}

void control_callback(void) {
