Adding few improvements:

- motors toggle button: allows for manual adjustments and silences motors
- pen toggle button: pen up and down positions are stored in EEPROM
- SMQB command: allows faster and smoother operation with custom version of eggbot extension (bartebor/eggbot_extensions)
- PRG button fix

Helper_Functions.ino

@@ -1,16 +1,38 @@
 void initHardware(){
+  // enable eeprom wait in avr/eeprom.h functions
+  SPMCSR &= ~SELFPRGEN;
+
+  loadPenPosFromEE();
+
   pinMode(enableRotMotor, OUTPUT); 
   pinMode(enablePenMotor, OUTPUT);  
+  pinMode(prgButton, INPUT_PULLUP);
+  pinMode(penToggleButton, INPUT_PULLUP);
+  pinMode(motorsButton, INPUT_PULLUP);
+
   rotMotor.setMaxSpeed(2000.0);
   rotMotor.setAcceleration(10000.0);
   penMotor.setMaxSpeed(2000.0);
   penMotor.setAcceleration(10000.0);
-  digitalWrite(enableRotMotor, HIGH) ;
-  digitalWrite(enablePenMotor, HIGH) ;
+  motorsOff();
   penServo.attach(servoPin);
-  penServo.write(penUpPos);
+  penServo.write(penState);
   }
-  
+
+void inline loadPenPosFromEE() {
+  penUpPos = eeprom_read_word(penUpPosEEAddress);
+  penDownPos = eeprom_read_word(penDownPosEEAddress);
+  penState = penUpPos;
+}
+
+void inline storePenUpPosInEE() {
+  eeprom_update_word(penUpPosEEAddress, penUpPos);
+}
+
+void inline storePenDownPosInEE() {
+  eeprom_update_word(penDownPosEEAddress, penDownPos);
+}
+
 void inline sendAck(){
 	Serial.print("OK\r\n");
 }
@@ -18,3 +40,4 @@ void inline sendAck(){
 void inline sendError(){
 	Serial.print("unknown CMD\r\n");
 }
+