diff --git a/src/Fermenter.cpp b/src/Fermenter.cpp
index 1530bbe..ea480fd 100644
--- a/src/Fermenter.cpp
+++ b/src/Fermenter.cpp
@@ -8,6 +8,7 @@
 #define SENSOR_GPIO           D4
 #define CONTROL_GPIO          D2
 #define CONTROL_PWM_BITS      10
+#define CONTROL_PWM_MAX       (pow(10, CONTROL_PWM_BITS))
 
 Dallas dallas(SENSOR_GPIO);
 
@@ -23,9 +24,9 @@ double temperatureMaxOvershoot = 5;
 
 double heaterPWM = 0;
 
-double proportional = 1;
+double proportional = 10;
 
-double integral = 0;
+double integral = 2;
 
 double derivative = 0;
 
@@ -36,7 +37,7 @@ void patrixSetup() {
   configLoad();
 
   pid.begin(&temperatureCurrent, &heaterPWM, &temperatureTarget, proportional, integral, derivative);
-  pid.setOutputLimits(0, pow(10, CONTROL_PWM_BITS) - 1);
+  pid.setOutputLimits(0, CONTROL_PWM_MAX - 1);
   pid.start();
 }
 
@@ -55,13 +56,16 @@ void patrixLoop() {
   if (emergencyCutOff) {
     heaterPWM = 0;
   }
+
+  heaterPWM = min(0.0, max(CONTROL_PWM_MAX, heaterPWM));
   analogWrite(CONTROL_GPIO, (int) round(heaterPWM));
 
   static unsigned long lastDebug = 0;
   unsigned long now = millis();
   if (now - lastDebug >= 1000) {
     lastDebug = now;
-    debug("p: %f | i: %f | d: %f | current: %4.1f | target: %4.1f | pwm: %f", proportional, integral, derivative, temperatureCurrent, temperatureTarget, heaterPWM);
+    int heaterPercent = (int) round(100.0 * heaterPWM / CONTROL_PWM_MAX);
+    debug("p: %f | i: %f | d: %f | current: %4.1f | target: %4.1f | pwm: %3d%%", proportional, integral, derivative, temperatureCurrent, temperatureTarget, heaterPercent);
     if (emergencyCutOff) {
       error("[EMERGENCY CUTOFF] temperatureCurrent (=%4.1f) > temperatureTarget + %4.1f (=%4.1f) [EMERGENCY CUTOFF]", temperatureCurrent, temperatureMaxOvershoot, temperatureTarget);
     }
@@ -93,8 +97,7 @@ bool setDouble(const char *name, double *destinationPtr, double min, double max)
   return true;
 }
 
-bool patrix_command(char *cmd) {
-  const char *first = strtok(cmd, " ");
+bool patrix_command(char *first) {
   bool result = false;
   if (strcmp(first, "over") == 0) {
     result = setDouble("over", &temperatureMaxOvershoot, 0, 20);