Arduino Mega2560 based Antenna Rotator Controller

Well after a long time I am back with a new project !

This is an attempt to build an Antenna rotator controller using Arduino Mega 2560 with a nice user interface showing the actual position of the antenna.

Idea of building a rotator controller is from my brother VU2JLH.

Following features are added in the controller project

1) Collect the Antenna position using HMC5883 Digital Compas
2) Auto/Manual mode operation . A potentiometer is used to control the speed in manual mode.
3) Stop/Resume inputs to pause the rotation and continue from that point.
4) 3.2 Inch TFT display
5) 3X4 Keypad for entering the target values.
6) Inflight entry to compensate the antenna rotation due to inertia.
7) I2C extender for long cable usage between shack and antenna.

HMC5883 will be attached to the antenna and a pair of I2C extenders are  used between the Arduino and HMC5883 . Use of I2C Extenders allow usage of long cable between shack and antenna tower.

3.2 inch TFT display is used for the UI. User can enter the Set point using the 3X4 Keypad.

Sequence to enter set-point is

1) Press the * key
2) Key in the  set-point value (0-360 deg)
3) Press the  # key

Controller will decide the rotation mode (clockwise or counter clockwise) based on the current position and set-point

An inflight value can be entered for stopping the Antenna before reaching the set point. This is applicable in case heavy antennas are controlled using this controller .

Sequence to enter inflight is hold the * key for 3 seconds, enter the inflight value , press the  # key.

Screen Shots

Schematics

Schematics of Motor Control Board

Source code of the Controller 

/*
 * An Arduino code  of Antenna Rotator Controller.
 * Copyright (c) 2016 Vinod E S (VU3ESV) , Jayaprakash L V (VU2JLH)
 * Version 1.0 - initial release
 * Version 1.1 - Inflight Entry after holding the "*" Key for 3 seconds

  * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.


 Harware Information :-

 1) Arduino Mega 2560R3 or its clones
 2) HMC5883 Accelerometer
 3) I2C Expander (NXP)
 4) 2.8Inch TFT Display
 5) Momentary push button switchs
 6) Potentiometer
 7) H-Bridge for driving the Motors
 */

#include <Wire.h> //I2C Arduino Library
#include <UTFT.h> // UTFT Library from Henning Karlsen (http://www.rinkydinkelectronics.com/library.php)
#include <UTFT_Geometry.h> //UTFT Geometry Library from Henning Karlsen (http://www.rinkydinkelectronics.com/library.php)
#include <Keypad.h>
#include <EEPROM.h>

const int centreX  = 320;
const int centreY  = 160;
const int diameter = 130;
const int x_Offset = 30;
const int y_Offset = 128;
const int z_Offset = 0;
const byte rows = 4; // Four rows
const byte cols = 3; // Three columns
const int maxDegreeDigits = 3; //maximum allowed input length
const int fixedInflight = 5;
const long maxInflight = 25;

extern uint8_t BigFont[];
extern uint8_t SmallFont[];
extern uint8_t SevenSegmentFull[];

#define BLACK   0x0000
#define BLUE    0x001F
#define RED     0xF800
#define GREEN   0x07E0
#define CYAN    0x07FF
#define MAGENTA 0xF81F
#define YELLOW  0xFFE0
#define WHITE   0xFFFF
#define ORANGE  0xFF00
#define address 0x1E //0011110b, I2C 7bit address of HMC5883
#define EEPROM_ModeStatus_Location 10     // The starting address of the EEPROM where the data is Stored (10.11.12.13)
#define EEPROMSetpointLocation        14
#define EEPROM_ScaleMax_Location        18
#define EEPROMInflightLocation        22

struct EEPROMValue //EEPROM Data Structure : Taken from G0MGX DDS VFO Code
{
  union{
    long Value;
    struct
    {
      unsigned char Byte1;
      unsigned char Byte2;
      unsigned char Byte3;
      unsigned char Byte4;
    }
    __attribute__((packed));
  }
  __attribute__((packed));
}
__attribute__((packed));

inline long ReadEEPROMValue(int16_t EEPROMStartAddress);              //Reads the values from EEPROM Like Calibration , set Parameters, etc
inline void SaveEEPROMValue(int16_t EEPROMStartAddress, long Value);  //Save the Value to EEPROM startingfrom the given StartAddress (4 Bytes of Data)
inline double ReadAngleFromAccelerometer(int x_Offset, int y_Offset);
inline void ResetInputBuffer(void);

// Define the Keymap
char keys[rows][cols] =
{
  {
    '1','2','3'                 }
  ,
  {
    '4','5','6'                 }
  ,
  {
    '7','8','9'                 }
  ,
  {
    '*','0','#'                 }
};

boolean UserEntryStarted = false;
boolean UserEntryFinished = true;
boolean InflightEntryStarted = false;
boolean InflightEntryFinished = true;
boolean stopFlag = true;
boolean modeValue = false;    // modeValue = false (Manual Mode), modeValue = true (Auto Mode)
boolean inputSelection = false; // false  =  SetPoint Input , True = inflight input

char KeyEntries[3];        //3 characters to store 0 to 360 Degrees
char dataBuffer[60];
char formattedDataBuffer[3];

int dx;
int dy;
int last_dx;
int last_dy;
int bufPtr = 0;
int CWMotor  =  10;
int CCWMotor = 11;
int Stop_ResumeSignal = 12;
int Manual_Auto_Mode = 13;
int ManualSpeedControl = 9;

long UserEntry = 0;
long DegreeInput = 0;
long Inflight = 0;
long storedModeValue = 0;
long scaleMax  = 0;

double angle = 0;

//Normal Keyboard Connected To Arduino
// Connect keypad ROW0, ROW1, ROW2 and ROW3 to these Arduino pins.
byte rowPins[rows] = {
  8, 7, 6, 5 };
// Connect keypad COL0, COL1 and COL2 to these Arduino pins.
byte colPins[cols] = {
  4, 3, 2 };

Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, rows, cols );

UTFT utftDisplay(ILI9481,38,39,40,41);

#define  FormatData(x) strcpy_P(dataBuffer, PSTR(x))

void setup(){
  Serial.begin(9600);
  utftDisplay.InitLCD();
  utftDisplay.InitLCD(LANDSCAPE);
  utftDisplay.clrScr();
  utftDisplay.setFont(BigFont);
  utftDisplay.setColor(255, 0, 0);
  utftDisplay.print("ANTENNA ROTATOR ", LEFT, 16);
  utftDisplay.print("CONTROLLER ", 40, 40);
  utftDisplay.drawLine(440, 160, 460, 160);
  utftDisplay.drawLine(180, 160, 200, 160);
  utftDisplay.drawLine(320, 20, 320, 40);
  utftDisplay.drawLine(320, 280, 320, 300);
  utftDisplay.setColor(255, 255, 0);
  utftDisplay.print("BEAM DIR", LEFT, 87);
  utftDisplay.setFont(SmallFont);
  utftDisplay.setColor(255, 100, 100);
  utftDisplay.print("SET DIR", LEFT, 210);
  utftDisplay.print("INFLIGHT", LEFT, 230);
  utftDisplay.setFont(BigFont);
  utftDisplay.setColor(255, 0, 0);
  utftDisplay.print("O", 95,  115);
  utftDisplay.setColor(255, 255, 255);
  utftDisplay.print("VU3ESV : VU2JLH",LEFT, 290);
  // Initialize I2C communications
  Wire.begin();
  //Put the HMC5883 IC into the correct operating mode
  Wire.beginTransmission(address); //open communication with HMC5883
  Wire.write(0x02); //select mode register
  Wire.write(0x00); //continuous measurement mode
  Wire.endTransmission();
  delay(300);
  last_dx = centreX;
  last_dy = centreY;

  DegreeInput = ReadEEPROMValue(EEPROMSetpointLocation);
  Inflight = ReadEEPROMValue(EEPROMInflightLocation);
  if(Inflight<fixedInflight)
  {
    Inflight = fixedInflight;
  }
  storedModeValue = ReadEEPROMValue(EEPROM_ModeStatus_Location);
  scaleMax = ReadEEPROMValue(EEPROM_ScaleMax_Location);
  if (storedModeValue ==0)
  {
    modeValue = false; //Manual Mode
  }
  else if (storedModeValue == 1)
  {
    modeValue = true;  // AutoMode
  }
  keypad.setDebounceTime(50);
  keypad.setHoldTime(3000);
  keypad.addEventListener(KeypadEventHandler); // Add an event listener for this keypad

  pinMode(ManualSpeedControl, OUTPUT);
  pinMode(CWMotor,OUTPUT);
  digitalWrite(CWMotor,LOW);
  pinMode(CCWMotor,OUTPUT);
  digitalWrite(CCWMotor,LOW);
  pinMode(Manual_Auto_Mode,INPUT);
  pinMode(Stop_ResumeSignal,INPUT);
  analogReference(DEFAULT);
}
double ReadAngleFromAccelerometer(int x_Offset, int y_Offset)
{
  //Tell the HMC5883 where to begin reading data
  Wire.beginTransmission(address);
  Wire.write(0x03); //select register 3, X MSB register
  Wire.endTransmission();
  //Read data from each axis, 2 registers per axis
  Wire.requestFrom(address, 6);
  int x,y,z; //triple axis data
  if(6<=Wire.available())
  {
    x = Wire.read() << 8 | Wire.read();
    z = Wire.read() << 8 | Wire.read();
    y = Wire.read() << 8 | Wire.read();
  }
  DrawRotatorPosition();
  return atan2((double)y + y_Offset,(double)x + x_Offset)* (180 / 3.141592654) + 180;
}
void loop()
{
  char key = keypad.getKey();
  angle = ReadAngleFromAccelerometer(y_Offset, x_Offset);
  if((digitalRead( Stop_ResumeSignal) == false)&& stopFlag == true)
  {
    stopFlag = false;
  }
  else if((digitalRead( Stop_ResumeSignal) == false)&& stopFlag == false)
  {  
    stopFlag = true;
  }
  if (stopFlag == true)
  {  
    digitalWrite(CWMotor,LOW);
    digitalWrite(CCWMotor,LOW);
    stopFlag = true;
    utftDisplay.setColor(0, 0, 0);
    utftDisplay.print("      ", RIGHT, 25);
  }
  else
  {
    if(((long)angle< DegreeInput )&& stopFlag == false)
    {  
      digitalWrite(CWMotor,HIGH);
      digitalWrite(CCWMotor,LOW);
      utftDisplay.setColor(0, 255, 255);
      utftDisplay.print("  CW ", RIGHT, 25);
    }
    if(((long)angle >DegreeInput)&& stopFlag == false)
    {  
      digitalWrite(CWMotor,LOW);
      digitalWrite(CCWMotor,HIGH);
      utftDisplay.setColor(0, 255, 255);
      utftDisplay.print(" CCW ", RIGHT, 25);
    }
    if(((long) angle == DegreeInput)||
      ((long) angle > DegreeInput-Inflight)&&
      ((long) angle < DegreeInput+ Inflight ))
    {  
      digitalWrite(CWMotor,LOW);
      digitalWrite(CCWMotor,LOW);
      stopFlag = true;
      utftDisplay.setColor(0, 0, 0);
      utftDisplay.print("      ", RIGHT, 25);
    }
  }
  if((digitalRead( Manual_Auto_Mode) == false) && modeValue == false )
  {
    modeValue = true;  
    SaveEEPROMValue(EEPROM_ModeStatus_Location, 1);
  }
  else if((digitalRead( Manual_Auto_Mode) == false) && modeValue == true )
  {
    modeValue = false;
    SaveEEPROMValue(EEPROM_ModeStatus_Location, 0);
  }
  if (modeValue ==  false)
  {
    if(stopFlag == false)
    {
      int spdValue = analogRead(A0);
      spdValue = map(spdValue, 0, 1023, 0 , 255);
      analogWrite(ManualSpeedControl, spdValue);
    }
    else
    {
      analogWrite(ManualSpeedControl, 0);
    }
    utftDisplay.setColor(0, 255, 255);
    utftDisplay.print("Manual ", RIGHT, 295);
  }
  else
  {
    if(stopFlag == false)
    {
      int rotationValue =abs( (int)(DegreeInput- (long) angle)); /* Irrespective of the Direction the difference in value needs to be considered for PWM
       // , Stoping is based on Cw/CCW outputs*/
      //Use Serial Print to check the value of rotationValue variable
      int scaleRotationValue =  rotationValue *4;
      int scaleMaxValue = scaleMax *4;
      int newSpeedValue = map(scaleRotationValue,0,scaleMaxValue, 0,255);   //The Scaling needs to be fine tuned based on the Test.    
      analogWrite(ManualSpeedControl, newSpeedValue);
    }
    else
    {
      analogWrite(ManualSpeedControl, 0);
    }
    utftDisplay.setColor(0, 255, 255);
    utftDisplay.print("    Auto ", RIGHT, 295);
  }
  dx = (diameter * cos((angle-90)*3.14/180)) + centreX;    // calculate X position
  dy = (diameter * sin((angle-90)*3.14/180)) + centreY;    // calculate Y position
  utftDisplay.setColor(BLACK);
  DrawArrow(last_dx,last_dy, centreX, centreY, 8, 8);        // Erase last arrow    
  utftDisplay.setColor(GREEN);
  DrawArrow(dx,dy, centreX, centreY, 8, 8);                  // Draw arrow in new position
  last_dx = dx;
  last_dy = dy;
  delay(25);
  utftDisplay.setFont(SevenSegmentFull);
  utftDisplay.setColor(255, 0, 127);
  int a =(int)angle;
  sprintf(formattedDataBuffer, FormatData("%03d"),a);
  utftDisplay.print(formattedDataBuffer, LEFT, 135);
  if(UserEntryFinished == true)
  {
    utftDisplay.setFont(BigFont);
    utftDisplay.setColor(0, 255, 0);
    utftDisplay.printNumI(DegreeInput,80,205);
  }
  if(InflightEntryFinished == true)
  {
    utftDisplay.setFont(BigFont);
    utftDisplay.setColor(0, 255, 0);
    utftDisplay.printNumI(Inflight,80,225);
  }
  utftDisplay.setFont(BigFont);
  utftDisplay.setColor(0, 100, 255);
  if((angle < 22.5)  || (angle > 337.5 ))utftDisplay.print("     North", LEFT, 260);
  if((angle > 22.5)  && (angle < 67.5 )) utftDisplay.print("North-East", LEFT, 260);
  if((angle > 67.5)  && (angle < 112.5 ))utftDisplay.print("      East", LEFT, 260);
  if((angle > 112.5) && (angle < 157.5 ))utftDisplay.print("South-East", LEFT, 260);
  if((angle > 157.5) && (angle < 202.5 ))utftDisplay.print("     South", LEFT, 260);
  if((angle > 202.5) && (angle < 247.5 ))utftDisplay.print("South-West", LEFT, 260);
  if((angle > 247.5) && (angle < 292.5 ))utftDisplay.print("      West", LEFT, 260);
  if((angle > 292.5) && (angle < 337.5 ))utftDisplay.print("North-West", LEFT, 260);
}

void KeypadEventHandler(KeypadEvent key)
{
  if (key != NO_KEY)
  {
    switch (keypad.getState())
    {
    case IDLE:
    case RELEASED:
      break;
    case HOLD:
      switch (key)
      {
        case '*':      
        if (inputSelection == true)
        {
          utftDisplay.setFont(BigFont);
          utftDisplay.setColor(255, 0, 127);
          utftDisplay.print("   ",80,225);
          ResetInputBuffer();
          UserEntry = 0;
          InflightEntryStarted = true;
          InflightEntryFinished = false;
        }
        break;
      }
      break;
    case PRESSED:
      switch (key)
      {
      case '#':
        if (inputSelection == false)
        {
          UserEntryFinished = true;
          UserEntryStarted = false;
          if((UserEntry < 360) )
          {
            //If the User SetPoint is less than Inflight then we can't accept the set point
            if(UserEntry> Inflight)
            {
              DegreeInput = UserEntry;
              SaveEEPROMValue(EEPROMSetpointLocation, DegreeInput);
              scaleMax = abs( (int)(DegreeInput- (long) angle));
              SaveEEPROMValue (EEPROM_ScaleMax_Location, scaleMax);
              utftDisplay.setFont(BigFont);
              utftDisplay.setColor(BLACK);
              utftDisplay.print("    ",80,205);
              stopFlag = false;
            }
            else
            {
              //Show Error in UI
            }    
          }
          else
          {
            utftDisplay.print("    ",80,205);
            DegreeInput = ReadEEPROMValue(EEPROMSetpointLocation);
          }
          inputSelection = true;
        }
        else
        {
          InflightEntryFinished = true;
          InflightEntryStarted = false;
          if((UserEntry < maxInflight) )
          {
            Inflight = UserEntry;
            SaveEEPROMValue(EEPROMInflightLocation, Inflight);
            utftDisplay.setFont(BigFont);
            utftDisplay.setColor(BLACK);
            utftDisplay.print("    ",80,225);
            stopFlag = false;
          }
          else
          {
            utftDisplay.print("    ",80,225);
            Inflight = ReadEEPROMValue(EEPROMInflightLocation);
          }
          inputSelection = false;
        }
        break;      
      case '*':
        if (inputSelection ==false)
        {
          utftDisplay.setFont(BigFont);
          utftDisplay.setColor(255, 0, 127);
          utftDisplay.print("   ",80,205);
          ResetInputBuffer();
          UserEntry = 0;
          UserEntryStarted = true;
          UserEntryFinished = false;
        }      
        break;
      case '0':
      case '1':
      case '2':
      case '3':
      case '4':
      case '5':
      case '6':
      case '7':
      case '8':
      case '9':
        if (bufPtr < maxDegreeDigits)
        {
          KeyEntries[bufPtr] = key;
          bufPtr++;          
          UserEntry = atol (KeyEntries);
          utftDisplay.setFont(BigFont);
          utftDisplay.setColor(255, 0, 127);
          if (UserEntryStarted == true)
          {
            utftDisplay.printNumI(UserEntry,80,205);
          }
          if (InflightEntryStarted == true)
          {
            utftDisplay.printNumI(UserEntry,80,225);
          }
        }
        break;  
      }
      break;
    }
  }
}

void DisplayUserEntry(int x, int y, String userData)
{
  utftDisplay.setColor(RED);
  utftDisplay.setFont(BigFont);
  utftDisplay.print(userData,x,y);
}

void DrawArrow(int x2, int y2, int x1, int y1, int arrowLength, int arrowWidth)
{
  float distance;
  int dx, dy, x2Outer,y2Outer,x3,y3,x4,y4,k;
  distance = sqrt(pow((x1 - x2), 2) + pow((y1 - y2), 2));
  dx = x2 + (x1 - x2) * arrowLength / distance;
  dy = y2 + (y1 - y2) * arrowLength / distance;
  k = arrowWidth / arrowLength;
  x2Outer = x2 - dx;
  y2Outer = dy - y2;
  x3 = y2Outer * k + dx;
  y3 = x2Outer * k + dy;
  x4 = dx - y2Outer * k;
  y4 = dy - x2Outer * k;
  utftDisplay.drawLine(x1, y1, x2, y2);
  utftDisplay.drawLine(x1, y1, dx, dy);
  utftDisplay.drawLine(x3, y3, x4, y4);
  utftDisplay.drawLine(x3, y3, x2, y2);
  utftDisplay.drawLine(x2, y2, x4, y4);
}

void DrawRotatorPosition()
{
  int dxOuter, dyOuter, dxi, dyi;
  utftDisplay.setColor(255, 128, 0);
  utftDisplay.drawCircle(centreX,centreY,diameter);  // Draw compass circle
  for (float i = 0; i <360; i = i + 22.5) {
    utftDisplay.setColor(255, 128, 0);
    dxOuter = diameter * cos((i-90)*3.14/180);
    dyOuter = diameter * sin((i-90)*3.14/180);
    dxi = dxOuter * 0.98;
    dyi = dyOuter * 0.98;
    utftDisplay.drawLine(dxi+centreX,dyi+centreY,dxOuter+centreX,dyOuter+centreY);
  }
  DisplayUserEntry((centreX-8),(centreY-157),"N");
  DisplayUserEntry((centreX-8),(centreY+145),"S");
  DisplayUserEntry((centreX+141),(centreY-7),"E");
  DisplayUserEntry((centreX-160),(centreY-7),"W");
}

void ResetInputBuffer()
{
  int length = sizeof(KeyEntries);
  for (int i = 0; i < length; i++)
  {
    KeyEntries[i] = '\0';
  }
  bufPtr = 0;
}

//Reads and returns the stored value specified in the EEPROM Start Address
long ReadEEPROMValue(int16_t EEPROMStartAddress)
{
  volatile EEPROMValue eepromVal;
  eepromVal.Byte1 = EEPROM.read(EEPROMStartAddress);
  eepromVal.Byte2 = EEPROM.read(EEPROMStartAddress+1);
  eepromVal.Byte3 = EEPROM.read(EEPROMStartAddress+2);
  eepromVal.Byte4 = EEPROM.read(EEPROMStartAddress+3);
  return eepromVal.Value;
}
/*Stores the specified value in the EEPROM  from Start Address
 EEPROM Write will only happens when the stored value and new value are different.
 This will save the number of Writes to the EEPROM.*/
void SaveEEPROMValue(int16_t EEPROMStartAddress, long Value)
{
  volatile EEPROMValue eepromVal;
  eepromVal.Value = ReadEEPROMValue(EEPROMStartAddress);
  if(eepromVal.Value != Value)
  {
    eepromVal.Value = Value;
    EEPROM.write(EEPROMStartAddress,eepromVal.Byte1);
    EEPROM.write(EEPROMStartAddress+1,eepromVal.Byte2);
    EEPROM.write(EEPROMStartAddress+2,eepromVal.Byte3);
    EEPROM.write(EEPROMStartAddress+3,eepromVal.Byte4);
  }
}


I have used the UTFT library from Henning Karlsen  (Rinky-Dink Electronics) and the same has to be downloaded before compiling the sketch.

Please note : This code is not meant for any commercial use.