I'm looking to teach basic Arduino stuff to middle/high school students outside of the United States, preferably in countries that need a little greater assistance in teaching such a topic. Does anyone have any pointers? Thanks!

Ah, okay that makes sense. I was actually using analogWrite initially for the logic pins and digitalWrite for the enablePin in order to slow the motor down, since it was going so fast.

Here's a little video from the other day. More documentation to come in a bit.  Might've been my soldering or something, but it kept breaking down during the show.  I kept having to restart the programs. Additionally, something happened with the midway feature again.

https://www.youtube.com/watch?v=JXkHI_2WEGQ&feature=youtu.be

Art show for it is later today. I'll probably put up some nice HQ videos later.

Yeah, I learned a ridiculous amount working on this project. Thanks for all the help, seriously.

Awesome! So my phone died and you can't really see anything on my webcam but pressing the three states on the iPad now works for 0, 512, and 1023. It jitters in the middle now for maybe a second and then it stops. Thank ya! Thank ya! Thank ya! I touched it up a bit to suit my needs.

Code:

//=====INITIALIZE PINS========

const int PinA1 = 6;    // H-bridge leg 1 (pin 2, 1A) PWM
const int PinA2 = 5;    // H-bridge leg 2 (pin 7, 2A) PWM
const int enablePin = 9;    // H-bridge enable pin

//For proper lineTrack readings, insert 2 to A5, 3 to 5V, 1 to GND
int lineTrack = A5;    //line track for position reading

int inByte = 0;   // for incoming serial data

int pos;
int potVal;
int posRead;
//=============================

void setup(){

  Serial.begin(57600);   

  // set the line track as input
  pinMode(lineTrack, INPUT);

  //set the motor logic pins and enable pin as outputs
  pinMode(PinA1, OUTPUT);
  pinMode(PinA2, OUTPUT);
  pinMode(enablePin, OUTPUT);
}

void loop() {

  potVal = analogRead(lineTrack);
  posRead = analogRead(lineTrack);

  // if we get a valid byte, read analog ins:
  if (Serial.available() > 0) {

    // get incoming byte:
    inByte = Serial.read();

    switch (inByte) {
    case 'a':   
      motorMoveA(0);
      break;
    case 'b':   
      motorMoveA(1023);
      break;
    case 'c':   
      motorMoveA(512);
      break;
    default:
      motorStop();
      break;
    }
  }
}

void motorMoveA(int target)
{
  pos;
  potVal = analogRead(lineTrack);
  posRead = analogRead(lineTrack);

  //Move backwards if potValue less than or equal target
  if ( potVal > target)
  { 
    do
    {
      posRead = analogRead(lineTrack);
      int Speed=map (pos,posRead, target, 255,0);
      analogWrite (enablePin,Speed);
      analogWrite (PinA1, 180);       
      analogWrite (PinA2, 30);
      potVal = analogRead(lineTrack);
      pos = potVal;
    }
    while (pos > target);
  }


  //Move forward if potValue less than target
  if (potVal < target)     
  {
    do
    {
      posRead = analogRead(lineTrack);
      int Speed=map (pos,posRead, target,255,0);
      analogWrite (enablePin,Speed);
      analogWrite (PinA1, 30);       
      analogWrite (PinA2, 180);
      potVal = analogRead(lineTrack);
      pos = potVal;
    }
    while
      (pos < target);
  }

  if (potVal == target){
    digitalWrite (enablePin,HIGH);
    digitalWrite (PinA1,HIGH);
    digitalWrite (PinA2,HIGH);
    return;
  }
}

void motorStop()
{
  digitalWrite (enablePin,HIGH);
  digitalWrite (PinA1,HIGH);
  digitalWrite (PinA2,HIGH);
  return;
}

Not sure if I submitted a working code, this one's more efficient.

Code:

//=====INITIALIZE PINS========

int PinA1 = 6;    // H-bridge leg 1 (pin 2, 1A) PWM
int PinA2 = 5;    // H-bridge leg 2 (pin 7, 2A) PWM
int enablePin = 9;    // H-bridge enable pin

//For proper lineTrack readings, insert 2 to A5, 3 to 5V, 1 to GND
int lineTrack = A5;    //line track for position reading
int potVal;

int inByte = 0;   // for incoming serial data

// These variables will change:
int sensorMin = 1023;  // minimum sensor value
int sensorMax = 0;     // maximum sensor value
int sensorValue = 0;         // the sensor value
//=============================

void setup(){

  Serial.begin(57600);   

  // set the line track as input
  pinMode(lineTrack, INPUT);

  //set the motor logic pins and enable pin as outputs
  pinMode(PinA1, OUTPUT);
  pinMode(PinA2, OUTPUT);
  pinMode(enablePin, OUTPUT);
}

void loop() {

  potVal = analogRead(lineTrack);

  // if we get a valid byte, read analog ins:
  if (Serial.available() > 0) {

    // get incoming byte:
    inByte = Serial.read();

    if (inByte == 97) {
      moveToTarget1(0);
    }


    if (inByte == 98) {
      moveToTarget1(100);
    }


    if (inByte == 99) {
      moveToTarget1(50);
    }
  }
}

void calibrate() {
   
  // read the sensor
  potVal = analogRead(lineTrack);

  // record the maximum sensor value
  if (sensorValue > sensorMax) {
    sensorMax = sensorValue;
  }

  // record the minimum sensor value
  if (sensorValue < sensorMin) {
    sensorMin = sensorValue;
  }
}

void moveToTarget1(int target)
{

  int pos;
  calibrate();
  potVal = analogRead(lineTrack);
  // apply the calibration to the sensor reading
  potVal = map(potVal, sensorMin, sensorMax, 0, 110);
  // in case the sensor value is outside the range seen during calibration
  potVal = constrain(potVal, 0, 110);


  if (potVal != target || potVal != target+1 || potVal != target-1){
    //Move backwards if potValue less than or equal target
    if ( potVal > target)
    { 
      digitalWrite(enablePin, HIGH);
      analogWrite (PinA1, 150);  //Move backwards
      analogWrite (PinA2, 30);
      potVal = analogRead(lineTrack);
      pos = potVal;
    }
    //Move forward if potValue less than target
    if ( potVal < target )     
    {
      digitalWrite(enablePin, HIGH);
      analogWrite (PinA1, 30);        //Move forward
      analogWrite (PinA2, 150);
      potVal = analogRead(lineTrack);
      pos = potVal;
    }
  }
}

Very very very very close!

So I've gotten it to stop in the middle, except it shakes fervently back and forth in the middle.

I think it has to do with conflicting messages in the motor move function.

Code:

//=====INITIALIZE PINS========

int PinA1 = 6;    // H-bridge leg 1 (pin 2, 1A) PWM
int PinA2 = 5;    // H-bridge leg 2 (pin 7, 2A) PWM
int enablePin = 9;    // H-bridge enable pin

//For proper lineTrack readings, insert 2 to A5, 3 to 5V, 1 to GND
int lineTrack = A5;    //line track for position reading
int potVal;

int inByte = 0;   // for incoming serial data
//=============================

void setup(){

  Serial.begin(57600);   

  // set the line track as input
  pinMode(lineTrack, INPUT);

  //set the motor logic pins and enable pin as outputs
  pinMode(PinA1, OUTPUT);
  pinMode(PinA2, OUTPUT);
  pinMode(enablePin, OUTPUT);
}

void loop() {

  // set enablePin high so that motor can turn on:
  potVal = analogRead(lineTrack);

  // if we get a valid byte, read analog ins:
  if (Serial.available() > 0) {
    // get incoming byte:
    inByte = Serial.read();
    Serial.println(inByte);

    if (inByte == 97) {
      moveToTarget1(0);
    }

    if (inByte == 98) {
      moveToTarget1(1023);
    }

    if (inByte == 99) {
      moveToTarget1(512);
    }
  }
}

void moveToTarget1(int target)
{
  int pos;
  potVal = analogRead(lineTrack);

  if ( potVal > (target) )
  {
    digitalWrite(enablePin, HIGH);
    analogWrite (PinA1, 150);  //Move backwards
    analogWrite (PinA2, 30);
    potVal = analogRead(lineTrack);
    pos = potVal;
  }


  if ( potVal < (target) )
  {
    digitalWrite(enablePin, HIGH);
    analogWrite (PinA1, 30);        //Move forward
    analogWrite (PinA2, 150);
    potVal = analogRead(lineTrack);
    pos = potVal;
  }

  if ( potVal < target+3 && potVal >target-3)
  {
    digitalWrite(enablePin, LOW);  //Stop
    digitalWrite (PinA1, HIGH);
    digitalWrite (PinA2, HIGH);
    potVal = analogRead(lineTrack);
    pos = potVal;
  }
}

Are you sure about case 0? This example was built into Arduino:

Code:

/*
  Switch statement
 
 Demonstrates the use of a switch statement.  The switch
 statement allows you to choose from among a set of discrete values
 of a variable.  It's like a series of if statements.
 
 To see this sketch in action, but the board and sensor in a well-lit
 room, open the serial monitor, and and move your hand gradually
 down over the sensor.
 
 The circuit:
 * photoresistor from analog in 0 to +5V
 * 10K resistor from analog in 0 to ground
 
 created 1 Jul 2009
 modified 9 Apr 2012
 by Tom Igoe
 
 This example code is in the public domain.
 
 http://www.arduino.cc/en/Tutorial/SwitchCase
 */

// these constants won't change. They are the
// lowest and highest readings you get from your sensor:
const int sensorMin = 0;      // sensor minimum, discovered through experiment
const int sensorMax = 600;    // sensor maximum, discovered through experiment

void setup() {
  // initialize serial communication:
  Serial.begin(9600); 
}

void loop() {
  // read the sensor:
  int sensorReading = analogRead(A0);
  // map the sensor range to a range of four options:
  int range = map(sensorReading, sensorMin, sensorMax, 0, 3);

  // do something different depending on the
  // range value:
  switch (range) {
  case 0:    // your hand is on the sensor
    Serial.println("dark");
    break;
  case 1:    // your hand is close to the sensor
    Serial.println("dim");
    break;
  case 2:    // your hand is a few inches from the sensor
    Serial.println("medium");
    break;
  case 3:    // your hand is nowhere near the sensor
    Serial.println("bright");
    break;
  }
  delay(1);        // delay in between reads for stability
}

[and only when I add high output to the enable pin right at the start of void loop()]

I've got it on its way. I made the cases into 0, 1, 2 instead of a, b, c, and am sending those numbers from Processing. Only case 2 (move motor halfway) works, but it shoots all the way forward, and only when I add high output to the enable pin right at the start of void loop(), but when I tried moving it back with my finger it's unable to go past midpoint (b/c I've tried out all the cases on the iPad via TouchOSC). So it's getting the messages but something's up with the enable pin.

Code:

const int Pot     = A5;  //Set the Linear Pot middle pin to Arduino A5 port
const int Enable =  9;  //Set the Motor controller pin on pin 9 Arduino  
const int  pin1A      =  6;  //Set the Motor Controller pin A1 to port 6;
const int pin2A      =  5;  //Set the Motor Controller pin A2 to port 5;
int Target        =  0;  //Target is the position we want the motor to move to
int Speed         =  0;  //Speed Control for motor
void setup()
{
  pinMode (Pot,INPUT);          //Set Pot as Input  
  pinMode (Enable,OUTPUT);  //Set Enable as Output
  pinMode (6,OUTPUT);       //Set A1 as Output
  pinMode (5,OUTPUT);       //Set A2 as Output
  Serial.begin(57600);             //Initialize Serial Communication at 9600 baud rate
}

void loop() {
 
  analogWrite(Enable, 255);

  if (Serial.available() > 0)
  {
    int inByte = Serial.read();
    switch (inByte)
    {
    case 0:
      MoveMotor(0);
      break;
    case 1:    
      MoveMotor(512);
      break;    
    case 2:    
      MoveMotor(1023);
      break;

//    default:
//      MotorStop();
//      break;
    }
  }
}

void MoveMotor(int Target)
{
  int PotVal =analogRead (Pot);
  if (PotVal > Target)
  {
    Speed = map (PotVal,Target,PotVal,0,255);
    analogWrite (Enable, Speed);
    digitalWrite (pin1A, HIGH);
    digitalWrite (pin2A, LOW);
  }
  if (PotVal < Target)
  {
    Speed = map (PotVal,PotVal,Target,0,255);
    analogWrite (Enable, Speed);
    digitalWrite (pin1A, LOW);
    digitalWrite (pin2A,HIGH);
  }
  else
  {
    digitalWrite (Enable,HIGH);
    digitalWrite (pin1A, LOW);
    digitalWrite (pin2A, LOW);
    return;
  }
}
void MotorStop()
{
  digitalWrite (Enable,HIGH);
  digitalWrite (pin1A, LOW);
  digitalWrite (pin2A, LOW);
  return;
}

So, for my code in the first post in this thread, once I open Processing and run the program (thus sending serial info) I instantly hear the motor, it's quite noisy when it's on (you can hear it in the video: https://www.youtube.com/watch?v=R4vXC0ugHZA&feature=plcp). All the subsequent codes that I've worked on since, the motor won't even turn on...which is usually the first sign of good news.

Hrmm, no luck :/

Yeah, they should open just fine.

Here's the code. I've split them up in tabs to keep it a bit organized (thus the zip).

So, I figure it might be best to give you context so you're not confused. I have two puppets, Obama and Romney, with this motor as a Pinocchio nose that moves forward or backwards based on the truthfulness of a selected statement. The statements are selected via TouchOSC on an iPad.

I've attached my processing code below this one.

Code:

//=====INITIALIZE PINS========

int switchPin = 7;    // switch input
int motor1APin = 6;    // H-bridge leg 1 (pin 2, 1A) PWM
int motor2APin = 5;    // H-bridge leg 2 (pin 7, 2A) PWM
int enablePin = 9;    // H-bridge enable pin

//For proper lineTrack readings, insert 2 to A5, 3 to 5V, 1 to GND
int lineTrack = 5;    //line track for position reading
int potVal;
int prevState; 

int incomingByte;   // for incoming serial data
//=============================

void setup(){

  Serial.begin(57600);   

  // set the switch pin and line track as inputs:
  pinMode(switchPin, INPUT);
  pinMode(lineTrack, INPUT);

  //set the motor logic pins and enable pin as outputs
  pinMode(motor1APin, OUTPUT);
  pinMode(motor2APin, OUTPUT);
  pinMode(enablePin, OUTPUT);

}

void loop() {

  // set enablePin high so that motor can turn on:
  digitalWrite(enablePin, HIGH);

  readSerial();

  //Cases are named by previous state, followed by new state
  lieTruth();
  truthLie();
  truthHalf();
  lieHalf();
  halfTruth();
  halfLie();
}


//If previous state was lie and new state is a truth, move backwards all the way
void lieTruth (){
  if (prevState == 2 && incomingByte == 65){
    //    //Obtain position reading
    //    int potVal = analogRead(lineTrack);  //read the line positioning
    //    int Speed = map (potVal,potVal,0,255,0);  //Map from 1023-0, HIGH-LOW
    do
    {
      //      analogWrite (enablePin, Speed);
      motorBackward();
      potVal = analogRead(lineTrack);
    }
    while (analogRead(lineTrack) >= 0);
    if (potVal == 0){
      motorStop();
    }
  }
}


//If previous state was truth and new state is a lie, move forward all the way
void truthLie(){
  if (prevState == 1 && incomingByte == 66){
    //Obtain position reading
    //    int potVal = analogRead(lineTrack);  //read the line positioning
    //    int Speed = map (potVal,potVal,1023,255,0);    //Map from 0-1023, HIGH-LOW
    do
    {
      //      analogWrite (enablePin, Speed);
      motorForward();
      potVal = analogRead(lineTrack);
    }
    while (analogRead(lineTrack) <= 1023);
    if (potVal == 1023){
      motorStop();
    }
  }
}

//If prevState was truth and new state half truth. Go forwards halfway
void truthHalf(){
  if (prevState == 1 && incomingByte == 67){
    //Obtain position reading
    //    int potVal = analogRead(lineTrack);  //read the line positioning
    //    int Speed = map (potVal,potVal,512,255,0);  //Map from 0-512, HIGH-LOW
    do
    {
      //      analogWrite (enablePin, Speed);
      motorForward();
      analogRead(lineTrack);
    }
    while (analogRead(lineTrack) >= 513);
    if (potVal == 512){
      motorStop();
    }
  }
}

//If prevState was lie and new state half truth. Go backwards halfway
void lieHalf(){
  if (prevState == 2 && incomingByte == 67){
    //Obtain position reading
    //    int potVal = analogRead(lineTrack);  //read the line positioning
    //    int Speed = map (potVal,potVal,512,255,0);  //Map from 1023-512 to HIGH-LOW
    do
    {
      //      analogWrite (enablePin, Speed);
      motorBackward();
      analogRead(lineTrack);
    }
    while (analogRead(lineTrack) >= 511);
    if (potVal == 512){
      motorStop();
    }
  }
}

//If prevState was half-truth and new state truth. Go backwards halfway
void halfTruth(){
  if (prevState == 3 && incomingByte == 65){
    //Obtain position reading
    //    int potVal = analogRead(lineTrack);  //read the line positioning
    //    int Speed = map (potVal,potVal,0,255,0);    //Map from 512-0, HIGH-LOW
    do
    {
      //      analogWrite (enablePin, Speed);
      motorBackward();
      analogRead(lineTrack);
    }
    while (analogRead(lineTrack) <= 513);
    if (potVal == 0){
      motorStop();
    }
  }
}


//If prevState was half-truth and new state lie. Go forwards halfway
void halfLie(){
  if (prevState == 3 && incomingByte == 66){
    //Obtain position reading
    //    int potVal = analogRead(lineTrack);  //read the line positioning
    //    int Speed = map (potVal,potVal,1023,255,0);    //Map from 512-1023, HIGH-LOW
    do
    {
      //      analogWrite (enablePin, Speed);
      motorForward();
      analogRead(lineTrack);
    }
    while (analogRead(lineTrack) >= 511);
    if (potVal == 1023){
      motorStop();
    }
  }
}

void motorForward(){     
  analogWrite(motor1APin, 30);   
  analogWrite(motor2APin, 160);
}

void motorBackward(){
  analogWrite(motor1APin, 160); 
  analogWrite(motor2APin, 30); 
}


void motorStop(){
   analogWrite(motor1APin, 255); 
   analogWrite(motor2APin, 255);
  }

void readSerial(){

  int prevState; 
  //Allow previous states to be stored here in prevState
  // 1 = truth
  // 2 = lie
  // 3 = half-truth

  // read the incoming byte data from Processing:
  if (Serial.available() > 0) {
    incomingByte = Serial.read();
  }

  //Store data as previous states
  if (incomingByte == 65) {   //Truth
    prevState = 1;
  }
  else if(incomingByte == 66) {  //Lie
    prevState = 2;
  }
  else if(incomingByte == 67) {  //Half-truth
    prevState = 3;
  }

}

Processing code:

Code:

//libraries needed for arduino communication
import processing.serial.*;

//libraries needed for osc
import oscP5.*;
import netP5.*;

Serial arduinoPort;        //  Set arduinoPort as serial connection

OscP5 oscP5;
NetAddress myRemoteLocation;

//set/change port numbers here
int incomingPort = 8000;
int outgoingPort = 9000;

//set/change the IP address that the OSC data is being sent to
//127.0.0.1 is the local address (for sending osc to an application on the same computer)
String ipAddress = "127.0.0.1";

int truthVal;  //truthValue

void setup()
{
  size(100, 100);
  background(0);
  frameRate(25);

  /* start oscP5, listening for incoming messages at port 8000 */
  //for INCOMING osc messages (e.g. from Max/MSP)
  oscP5 = new OscP5(this, incomingPort); //port number set above

  arduinoPort = new Serial(this, Serial.list()[4], 57600);  //port 4 is Arduino to USB
}

// Incoming osc message are forwarded to the following oscEvent method. Write to the arduino here--------
// This method is called for each OSC message recieved
void oscEvent(OscMessage theOscMessage)
{

  println("### received an osc message.");
  println("addrpattern: "+theOscMessage.addrPattern());

  //Convert the OSC address pattern to a string
  String addr = theOscMessage.addrPattern();

  if (addr.equals("/o/truth") == true) //if the osc message reads obama truth
  {
    truthVal = 0;    //Set truthVal to 0
  }

  else if (addr.equals("/o/lie") == true) //if the osc message reads obama lie
  { 
    truthVal = 1;  //Set truthVal to 1
  }
  else if (addr.equals("/o/halfTruth") == true)
  {
    truthVal = 2;
  }
}


void draw()
{
  //write serial data to for the Arduino to read
  if (truthVal == 0) //if the osc message reads obama truth
  { 
    arduinoPort.write(65); 
    println("Obama Truth");
  }
  else if (truthVal == 1) //if the osc message reads obama truth
  { 
    arduinoPort.write(66);
    println("Obama Lie");
  }
  else if (truthVal == 2) //if the osc message reads obama truth
  { 
    arduinoPort.write(67);
    println("Obama Half-Truth");
  }
}

Any luck getting them open? I'll see what's up.

I'm using Arduino...though I have had Processing and Arduino sketches open in each other's platform. Have you checked default program that opens it?

Hrrrmm, something's gone awry. See attached zip file.

I have a feeling it has to do with the position of enablePin, where I analogRead the potVal in the do function or how I'm calling previous & new states.