intially upload

Software/split_flap_unit/splitFlapUnit.ino

@@ -0,0 +1,249 @@
+
+// (c) Walter Greger, internet.greger@me.com
+
+//libs
+#include <Wire.h>
+#include <Stepper.h>
+
+//constants i2c
+#define i2cAddress 1 //i2c address
+//constants stepper
+#define stepperIn1Pin 8
+#define stepperIn2Pin 9
+#define stepperIn3Pin 10
+#define stepperIn4Pin 11
+#define STEPS 2038 // 28BYJ-48, number of steps; sometimes 2038
+#define CALOFFSET 40 //40 for 01; 100 for 02; 00 for 03; 00 for 04; 00 for 5
+#define hallPin 5
+#define amountFlaps 45
+#define correctedSteps 2038
+#define stepperSpeed 15 //in rpm
+//constants others
+#define baudrate 9600
+#define rotationDirection 1
+
+//globals
+String displayedLetter = " ";
+String desiredLetter = " ";
+String letters[] = {" ","A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","Ä","Ö","Ü","0","1","2","3","4","5","6","7","8","9",":",".","-","?","!"};
+Stepper stepper(STEPS, stepperIn1Pin,stepperIn3Pin,stepperIn2Pin,stepperIn4Pin); //stepper setup
+bool lastInd1 = false; //store last status of phase
+bool lastInd2 = false; //store last status of phase
+bool lastInd3 = false; //store last status of phase
+bool lastInd4 = false; //store last status of phase
+float missedSteps = 0; //cummulate steps <1, to compensate via additional when reaching >1
+bool demoMode = false;
+bool demoInProgress = false;
+
+void setup() {
+  //initialize serial
+  Serial.begin(baudrate);
+  Serial.println("starting i2c slave");
+
+  //initialize i2c
+  Wire.begin(i2cAddress); //i2c address of this unit 
+  Wire.onReceive(receiveLetter); //call-function if for transfered letter via i2c 
+
+  //setup motor
+  pinMode(hallPin, INPUT);
+  calibrate(); //doing a calibration
+}
+
+void loop() {
+  static int i = 0;
+  //check if currently displayed letter differs from desired letter  
+  if((displayedLetter!=desiredLetter) && !demoMode ) rotateToLetter(desiredLetter);
+  else if(demoMode && !demoInProgress) {
+    demoInProgress = true;
+    showDemo();
+  }
+}
+
+//doing a calibration of the revolver using the hall sensor
+void calibrate() {
+  Serial.println("calibrate revolver");
+  bool reachedMarker = false;
+  stepper.setSpeed(stepperSpeed);
+  int i = 0;
+  while(!reachedMarker) {
+    int currentHallValue = digitalRead(hallPin);
+      if(currentHallValue == 1) {
+        //not reached yet
+        stepper.step(rotationDirection * 1);
+      }
+      else {
+        reachedMarker = true;
+        stepper.step(rotationDirection * CALOFFSET);
+        displayedLetter = " ";
+        missedSteps = 0;
+        stopMotor();
+      }
+      if(i > 3 * STEPS) {
+        displayedLetter = " ";
+        desiredLetter = " ";
+        reachedMarker = true; //safty aspect. if revolver turned 3 times without getting hall-signal, better turn of in terms of heating
+        Serial.println("calibration revolver failed");
+      }
+      i++;
+  }
+}
+
+//rotate to desired letter
+void rotateToLetter(String toLetter) {
+  //get letter position
+  int posLetter = -1;
+  int posCurrentLetter = -1;
+  size_t amountLetters = sizeof(letters) / sizeof(String);
+  for(int i = 0; i < amountLetters; i++) {
+    //current char
+    String currentSearchLetter = letters[i];
+    if(toLetter == currentSearchLetter) posLetter = i;
+    if(displayedLetter == currentSearchLetter) posCurrentLetter = i;
+  }
+  Serial.print("go to letter:");
+  Serial.println(toLetter);
+  //go to letter, but only if available (>-1)
+  if(posLetter > -1) { //check if letter exists
+    //check if letter is on higher index, then no full rotaion is needed
+    if(posLetter >= posCurrentLetter) {
+      Serial.println("direct");
+      //go directly to next letter, get steps from current letter to target letter
+      int diffPosition = posLetter - posCurrentLetter;
+      startMotor();
+      stepper.setSpeed(stepperSpeed);
+      //doing the rotation letterwise
+      for(int i=0;i<diffPosition;i++) {
+        float preciseStep = (float)correctedSteps/(float)amountFlaps;
+        int roundedStep = (int)preciseStep;
+        missedSteps = missedSteps + ((float)preciseStep - (float)roundedStep);
+        if(missedSteps > 1) {
+          roundedStep = roundedStep +1;
+          missedSteps--;
+        }
+        stepper.step(rotationDirection*roundedStep);
+      }
+    }
+    else {
+      //full rotation is needed, good time for a calibration
+      Serial.println("full rotation incl. calibration");
+      calibrate();
+      startMotor();
+      stepper.setSpeed(stepperSpeed);
+      for(int i=0;i<posLetter;i++) {
+        float preciseStep = (float)correctedSteps/(float)amountFlaps;
+        int roundedStep = (int)preciseStep;
+        missedSteps = missedSteps + (float)preciseStep - (float)roundedStep;
+        if(missedSteps > 1) {
+          roundedStep = roundedStep +1;
+          missedSteps--;
+        }
+        stepper.step(rotationDirection*roundedStep);
+      }
+    }
+    //store new position
+    displayedLetter = toLetter;
+    //rotation is done, stop the motor
+    delay(100); //important to stop rotation before shutting of the motor
+    stopMotor();
+  }
+  else {
+    Serial.println("letter unknown, go to space");
+    calibrate();
+    desiredLetter = " ";
+  }
+}
+
+//switching off the motor driver
+void stopMotor() {
+  lastInd1 = digitalRead(stepperIn1Pin);
+  lastInd2 = digitalRead(stepperIn2Pin);
+  lastInd3 = digitalRead(stepperIn3Pin);
+  lastInd4 = digitalRead(stepperIn4Pin);
+
+  digitalWrite(stepperIn1Pin,LOW);
+  digitalWrite(stepperIn2Pin,LOW);
+  digitalWrite(stepperIn3Pin,LOW);
+  digitalWrite(stepperIn4Pin,LOW);
+}
+
+void startMotor() {
+  digitalWrite(stepperIn1Pin,lastInd1);
+  digitalWrite(stepperIn2Pin,lastInd2);
+  digitalWrite(stepperIn3Pin,lastInd3);
+  digitalWrite(stepperIn4Pin,lastInd4);
+}
+
+void receiveLetter(int amount)
+{
+  byte bytes[amount];
+  int i = 0;
+  while(Wire.available()){
+    bytes[i] = Wire.read();
+    Serial.print("received byte:");
+    Serial.println(bytes[i]);
+    i++;
+  }
+
+  //convert it to utf string
+  size_t amountBytes = sizeof(bytes) / sizeof(byte);
+  String utfLetter;
+  //go through the bytes and get the utf letter
+  for(int i = 0; i < amountBytes; i++) {
+    int charLength = 2; //at least two bytes including null termination
+    if(bitRead(bytes[i],7)&&bitRead(bytes[i],6)) { //if true, utf char consists of at least two bytes + null termination
+      charLength++;
+      if(bitRead(bytes[i],5)) charLength++; //if true, utf char consists of at least three bytes + null termination
+      if(bitRead(bytes[i],4)) charLength++; //if true, utf char consists of four bytes+ null termination
+    }
+    byte aBuffer[charLength];
+    for(int j = 0; j < charLength; j++) {
+      aBuffer[j] = bytes[i+j];
+    }
+    //aBuffer[charLength] = 0; //terminate string with NULL byte at end
+    utfLetter = aBuffer;
+    //utfMessage.concat(utfLetter);
+    i = i + (charLength-1); //skip bytes corresponding to length of utf letter
+  }
+  //umlaute as capital
+  if(utfLetter == "ä") utfLetter = "Ä";
+  if(utfLetter == "ö") utfLetter = "Ö";
+  if(utfLetter == "ü") utfLetter = "Ü";
+  Serial.print("utf letter:");
+  Serial.println(utfLetter);
+  if (demoMode && !(utfLetter == "©")) {
+    demoMode = false;
+  }
+  else if(utfLetter == "©") {
+    demoMode = true;
+  }
+  else desiredLetter = utfLetter; //normal character)
+}
+
+void showDemo() {
+    demoMode = true;
+    size_t amountLetters = sizeof(letters) / sizeof(String);
+   //go directly to next letter, get steps from current letter to target letter
+   //doing the rotation letterwise
+   for(int i=0;i<amountLetters;i++) {
+    startMotor();
+    stepper.setSpeed(stepperSpeed);
+    float preciseStep = (float)correctedSteps/(float)amountFlaps;
+    int roundedStep = (int)preciseStep;
+    missedSteps = missedSteps + ((float)preciseStep - (float)roundedStep);
+    if(missedSteps > 1) {
+      roundedStep = roundedStep +1;
+      missedSteps--;
+    }
+    stepper.step(rotationDirection * roundedStep);
+    float timeForRotation = 60/stepperSpeed/amountLetters*1000;
+    delay(100);
+    stopMotor();
+    delay(1450);
+  }
+  delay(10000);
+  desiredLetter = " ";
+  Serial.print("shutting off demo mode");
+  demoMode = false;
+  demoInProgress = false;
+  desiredLetter = " ";
+}