I am working on my first Arduino project.  I have a pretty good understanding of the hardware, and some basic→moderate programing skills.  I have familiarized myself with the basic Arduino programming language, and the hardware requirements, but I am looking for some help/advice on my project. 

 

I am creating an autopilot for a trolling motor on a boat.  I am proceeding in several phases.

 

 

Phase one – Integrate the hardware controls to manipulate the motor, and create an Arduino script that allows me to control it from a wired remote.  ***Complete – See notes below***

 

Phase two – Integrate a 3-axis magnetometer (an possibly 3-axis gyro and 3-axis accelerometer to steady the readings) to allow the Arduino to control the direction and maintain a heading.

 

Phase three – integrate a gps unit and create trolling modes (i.e. zigzag, figure 8, or loop)

 

Phase four – integrate NMEA output from external GPS (i.e. garmin) into Arduino project to allow the Arduino to follow waypoints.

 

Phase five – Create wireless control.

 

 

My progress thus far incorporates a potentiometer and servo to control the throttle (attached to the carb linkage), and a pair of relays powering a hydraulic pump and cylinder to control the steering.  I would like to use a linear actuator rather than hydraulics.  I am currently using an Arduino Uno, and I know I will likely need a mega to handle the needed I/O ports.

 

For the wired control, I am using an (on)/off/(on) toggle for the steering switch, an on/off/(on) switch for the run/idle and mft (momentary full throttle), an off/(on) switch for the start and stop buttons, and a 10k potentiometer for the throttle control.  This requires a large project box for the wired control, I would like to slim this down by making a custom PCB based keypad, but I would need to waterproof it, I would appreciate any suggestions on creating a DIY rubber keypad.

 

Here is my script:

 

// Trolling Motor Throttle Control //

// by Adam Rogowicz a.rogowicz@gmail.com //

 

#include <Servo.h>

 

// hardware libraries:

Servo myservo;  // create servo object to control a servo

const int buttonPin_idle = 7;  // set the pin number of the run/idle button ** on/off button **

const int buttonPin_mft = 6;  // set the pin number of the mft button ** off/(on) button **

const int buttonPin_left = 5;  // set the pin number of the left control button ** off/(on) button **

const int buttonPin_right = 4;  // set the pin number of the right control button ** off/(on) button **

// !!not in use yet!! // const int buttonPin_heading = 8;  // set the pin number of the set heading button

const int relayPin_left =  3;  // set the pin number of the left control relay ** NO relay **

const int relayPin_right =  2;  // set the pin number of the right control relay ** NO relay **

const int relayPin_start =  11;  // set the pin number of the start control relay ** NO relay **

const int relayPin_stop =  10;  // set the pin number of the stop/kill engine control relay ** NC relay **

const int buttonPin_start =  13;  // set the pin number of the start button

const int buttonPin_stop =  12;  // set the pin number of the stop/kill engine button

 

// variables:

int buttonState_idle = 0;  // variable for reading the run/idle button status

int buttonState_mft = 0;  // variable for reading the mft button status

int buttonState_left = 0;  // variable for reading the left control button status

int buttonState_right = 0;  // variable for reading the right control button status

// !!not in use yet!! // int buttonState_heading = 0;   // variable for reading the set heading button status

int relayState_left = 0;  // variable for reading the left control relay status

int relayState_right = 0;  // variable for reading the right control relay status

int relayState_start = 0;  // variable for reading the start relay status

int relayState_stop = 0;  // variable for reading the stop/kill relay status

int buttonState_start = 0;  // variable for reading the start button status

int buttonState_stop = 0;  // variable for reading the stop/kill button status

int potpin = 0;  // analog pin used to connect the potentiometer ** 10K pot **

int val;  // variable to read the value from the analog pot pin

 

void setup() {

  myservo.attach(9);  // attaches the servo on pin 9 to the servo object

  // initialize the pins as an input or output:

  pinMode(buttonPin_idle, INPUT);

  pinMode(buttonPin_mft, INPUT);

  pinMode(buttonPin_left, INPUT);

  pinMode(buttonPin_right, INPUT);

  pinMode(buttonPin_heading, INPUT); 

  pinMode(relayPin_left, OUTPUT);

  pinMode(relayPin_right, OUTPUT);

  pinMode(relayPin_start, OUTPUT);

  pinMode(relayPin_stop, OUTPUT);

  pinMode(buttonPin_start, INPUT);

  pinMode(buttonPin_stop, INPUT);

}

 

void loop() {  // Start of loop

 

  buttonState_idle = digitalRead(buttonPin_idle); // read the state of the rin/idle button value

  buttonState_mft = digitalRead(buttonPin_mft); // read the state of the rin/idle button value

  buttonState_left = digitalRead(buttonPin_left); // read the state of the left control button value

  buttonState_right = digitalRead(buttonPin_right); // read the state of the right control button value

  buttonState_heading = digitalRead(buttonPin_heading); // read the state of the set heading button value

  // !!not in use yet!! // relayState_left = digitalRead(relayPin_left); // read the state of the left control relay value

  // !!not in use yet!! // relayState_right = digitalRead(relayPin_right); // read the state of the right control relay value

  buttonState_start = digitalRead(buttonPin_start); // read the state of the start button value

  buttonState_stop = digitalRead(buttonPin_stop); // read the state of the stop/kill button value

  // !!not in use yet!! // relayState_start = digitalRead(relayPin_start); // read the state of the start relay value

  // !!not in use yet!! // relayState_stop = digitalRead(relayPin_stop); // read the state of the stop/kill relay value

 

 

  if (buttonState_start == HIGH && buttonState_stop == LOW) {  // Start engine statement

    delay(15);

    digitalWrite(relayPin_stop, LOW);

    delay(15);

    digitalWrite(relayPin_start, HIGH);

    delay(15);  }

  else if (buttonState_stop == HIGH && buttonState_start == LOW) {  // Stop/Kill engine statement

    delay(15);

    digitalWrite(relayPin_start, LOW);

    delay(15);

    digitalWrite(relayPin_stop, HIGH);

    delay(15);  }

  else {

    digitalWrite(relayPin_start, LOW);

    digitalWrite(relayPin_stop, LOW);  }

 

 

  if (buttonState_idle == HIGH) {   // run/idle button statement

    myservo.write(15); }  // if run/idle button engaged, servo to 0 position

  else if (buttonState_mft == HIGH) {   // mft button statement

    myservo.write(164); }  // if mft button engaged, servo to 17 position

  else {

    val = analogRead(potpin);  // reads the value of the potentiometer (value between 0 and 1023)

    val = map(val, 0, 1023, 15, 164);  // scale it to use it with the servo (value between 0 and 180)

    myservo.write(val);  // sets the servo position according to the scaled value

    delay(15); }  // waits for the servo to get there

 

 

  if (buttonState_left == HIGH && buttonState_right == LOW) {  // left control statement

    delay(15);

    digitalWrite(relayPin_right, LOW);

    delay(15);

    digitalWrite(relayPin_left, HIGH);

    delay(15); }

  else if (buttonState_right == HIGH && buttonState_left == LOW) {  // right control statement

    delay(15);

    digitalWrite(relayPin_left, LOW);

    delay(15);

    digitalWrite(relayPin_right, HIGH); 

    delay(15); }

  else {

    digitalWrite(relayPin_left, LOW);

    digitalWrite(relayPin_right, LOW); }

 

}  // End of loop

 

At this point, I need to know if I need a 3-axis gyro and 3-axis accelerometer to accomplish my goal.  I assume it will help, but I don’t want to overcomplicate my project if it is unnecessary.

 

I would appreciate any advice on hardware, and I need a starting point for the software for phases two, three, and four, and any advice on hardware for phase five, wireless controller.

 

I would also love to integrate a means to put the Arduino into sleep mode (low power) when the motor is off.  I am not sure how this would work since the start button would need to be operative while in sleep mode.  I would also like to incorporate a small LCD in the wired control, a way to determine the engine RPMs (tachometer), and display RPMs, Mode, water temp and???  Another thing I would like to incorporate if possible is a way to read depth from a sonar transducer, and have the autopilot follow a bottom depth.