Optimized for low quality PD power supply

firmware/reflow/reflow.ino

@@ -10,16 +10,17 @@
    Start Btn: P1.4
    Stop Btn: P1.7
 */
+#include <Serial.h>
 #include <TouchKey.h>
 
-#define TEMP_PIN 11 //P1.1
-#define HEATER_PIN 34 //P3.4
-#define LED_PREHEAT 15 //P1.5
-#define LED_REFLOW 16 //P1.6
+#define TEMP_PIN 11     //P1.1
+#define HEATER_PIN 34   //P3.4
+#define LED_PREHEAT 15  //P1.5
+#define LED_REFLOW 16   //P1.6
 
 //Timing settings. Each cycle is approximately 100ms
-#define HOLDSTART_TIME 30 //START Button hold down time in cycles
-#define SOAKING_TIME 600 //SOAKING temperature upkeep time in cycles
+#define HOLDSTART_TIME 30  //START Button hold down time in cycles
+#define SOAKING_TIME 600   //SOAKING temperature upkeep time in cycles
 
 /*
  * Temperature Settings
@@ -32,16 +33,16 @@
  * Note that different setup (e.g. ref resistor value / NTC resistor value) might have different equations
  * You can experiment with yours and get a few data point to plot your own line
  */
-#define COOLDOWN_TEMP_ADC 255 //Room temperature
+#define COOLDOWN_TEMP_ADC 255  //Room temperature
 //Preheat temp & power
-#define PREHEAT_START_ADC 143 //150 degree C
-#define PREHEAT_TEMP_ADC 122 //160 degree C
-#define PREHEAT_PWR_PWM 155 //60% power output
+#define PREHEAT_START_ADC 143  //150 degree C
+#define PREHEAT_TEMP_ADC 122   //160 degree C
+#define PREHEAT_PWR_PWM 155    //60% power output
 //Reflow temp & power
-#define REFLOW_TEMP_ADC 58 //220 degree C
-#define REFLOW_PWR_PWM 255 //100% power output
+#define REFLOW_TEMP_ADC 58  //220 degree C
+#define REFLOW_PWR_PWM 255  //100% power output
 //Overheat cutoff temp
-#define CUTOFF_TEMP_ADC 53 //230 degree C
+#define CUTOFF_TEMP_ADC 53  //230 degree C
 
 //Func def
 bool updateHeaterPowerState();
@@ -50,8 +51,8 @@ int readTemp();
 
 
 //Runtimes
-bool reflowing = false; //Reflow has started
-bool reflowComplete = false; //Indicate if the stopping is done because of reflow complete
+bool reflowing = false;       //Reflow has started
+bool reflowComplete = false;  //Indicate if the stopping is done because of reflow complete
 /*
   Reflow Stages define what is the next state the hotplate should reach
   0: Standby
@@ -61,28 +62,36 @@ bool reflowComplete = false; //Indicate if the stopping is done because of reflo
   4: Cooling down
 */
 int reflowStages = 0;
-int startCountdown = HOLDSTART_TIME; //Hold for HOLDSTART_TIME to start to prevent accidental touches
-int cycleCounter = 0; //Record cycle time up to 10 seconds
+int startCountdown = HOLDSTART_TIME;  //Hold for HOLDSTART_TIME to start to prevent accidental touches
+int cycleCounter = 0;                 //Record cycle time up to 10 seconds
 int soakingCountdown = SOAKING_TIME;
 
 //Blink state controls
-bool blinkState = false; //If blinking this will be switching between true and false
-bool blinkYellow = true; //Slow blink yellow if enabled (Standby). Do not enable both yellow and red at the same time
-bool blinkRed = false; //Slow blink red if enable (End of Reflow). Do not enable both yellow and red at the same time
+bool blinkState = false;  //If blinking this will be switching between true and false
+bool blinkYellow = true;  //Slow blink yellow if enabled (Standby). Do not enable both yellow and red at the same time
+bool blinkRed = false;    //Slow blink red if enable (End of Reflow). Do not enable both yellow and red at the same time
 bool fastBlinkState = false;
 bool fastblinkRed = false;
 
 
 //Real-time temperature control targets
-int targetTempADC = 255; //Target ADC reading to reach, 255 = room temperature
-int targetPwrPWM = 0; //Target PWM cycle for heater, 255 = full power, 0 = off
-int offset = 0; //Allow +-offset for the ADC reading before reheating / cooling
+int targetTempADC = 255;  //Target ADC reading to reach, 255 = room temperature
+int targetPwrPWM = 0;     //Target PWM cycle for heater, 255 = full power, 0 = off
+int offset = 0;           //Allow +-offset for the ADC reading before reheating / cooling
 
 void setup() {
   //Enable the touch buttons
   //Enable all 6 channels:TIN2(P1.4),TIN5(P1.7)
   TouchKey_begin((1 << 2) | (1 << 5));
 
+  //refer to AN3891 MPR121 Baseline System for more details
+  TouchKey_SetMaxHalfDelta(192);      // increase if sensor value are more noisy
+  TouchKey_SetNoiseHalfDelta(4);      // If baseline need to adjust at higher rate, increase this value
+  TouchKey_SetNoiseCountLimit(10);    // If baseline need to adjust faster, increase this value
+  TouchKey_SetFilterDelayLimit(5);    // make overall adjustment slower
+  TouchKey_SetTouchThreshold(220);    // Bigger touch pad can use a bigger value
+  TouchKey_SetReleaseThreshold(150);  // Smaller than touch threshold
+
   //Set LED pins to output
   pinMode(LED_PREHEAT, OUTPUT);
   pinMode(LED_REFLOW, OUTPUT);
@@ -105,27 +114,27 @@ void loop() {
   //Main reflowing logics
   //Add delay to the end of each conditions so each loop cycle is approximate 100ms
   if (reflowing) {
-    bool tempReached = updateHeaterPowerState(); //This action takes 100ms
+    bool tempReached = updateHeaterPowerState();  //This action takes 100ms
     if (tempReached) {
       //This stage temperature reached. Move to next stage
       if (reflowStages == 1) {
         //Preheat stage completed. Enter soaking stage
         USBSerial_println("Preheat temperature reached. Soaking started");
-        targetTempADC = PREHEAT_TEMP_ADC; //Set temperature to soaking end temp
-        reflowStages = 2; //Set reflow stage to soaking
+        targetTempADC = PREHEAT_TEMP_ADC;  //Set temperature to soaking end temp
+        reflowStages = 2;                  //Set reflow stage to soaking
         soakingCountdown = SOAKING_TIME;
         fastblinkRed = true;
-      }else if (reflowStages == 3) {
-          //Reflowing target temperature reached. Start cooldown and shut down heater
-          USBSerial_println("Reflow completed. Cooling down");
-          reflowStages = 4;
-          blinkYellow = false;
-          blinkRed = true;
-          targetTempADC = COOLDOWN_TEMP_ADC;
-          targetPwrPWM = 0;
-
-          //Reflow ended. Wait until stop being press to exit this state
-        }
+      } else if (reflowStages == 3) {
+        //Reflowing target temperature reached. Start cooldown and shut down heater
+        USBSerial_println("Reflow completed. Cooling down");
+        reflowStages = 4;
+        blinkYellow = false;
+        blinkRed = true;
+        targetTempADC = COOLDOWN_TEMP_ADC;
+        targetPwrPWM = 0;
+
+        //Reflow ended. Wait until stop being press to exit this state
+      }
     }
 
     if (reflowStages == 2) {
@@ -140,8 +149,8 @@ void loop() {
         digitalWrite(LED_REFLOW, HIGH);
 
         //Set to reflow temperature
-        targetTempADC = REFLOW_TEMP_ADC; //Set the target temp to reflow
-        targetPwrPWM = REFLOW_PWR_PWM; //Set power rating to reflow
+        targetTempADC = REFLOW_TEMP_ADC;  //Set the target temp to reflow
+        targetPwrPWM = REFLOW_PWR_PWM;    //Set power rating to reflow
 
         //Update the reflow stage to 3
         reflowStages = 3;