Easy Arduino Robot – Modellismo e robotica amatoriale

ArduinoFan, un utente del sito Let’s Make Robots ha postato un progetto per realizzare un semplice quanto divertente robot utilizzando la scheda Arduino.  Si può vedere come il telaio del robot si basa su una basetta breadboard su cui sono attaccati i servi, l’Arduino e le altre parti tramite edel nastro biadesivo spesso (con supporto in schiuma acrilica) e delle fascette autobloccanti di plastica. OK, no nsarà come Wall-e ma ci sembra un ottimo progetto per i modellistici che vogliono avvicinarsi alla robotica e all’utilizzo di Arduino.

Puoi trovare le informazioni per il montaggio qui.

Materiali utilizzati:
(1) Arduino
(2) Continuous Rotation Servos
(1) Standard Servo
(1) Box per 4 batterie AA
(4) AA Batterie
(1) 1-1/4″ Caster Wheel
(2) Servo Mountable Wheels
(1) Sharp IR Sensor
(1) IR Sensor Servo Mount
(1) Breadboard da 840 contatti
Filo elettrico
Fascette autobloccanti
Nastro biadesivo

Ecco il coide da caricare su Arduino per gestire i servi.

Shawn – http://www.ArduinoFun.com
Arduino Sketch:
/*
* Brian Bailey *
* Drives servo robot and avoids obsticles using Sharp IR range finder
* http://bunedoggle.com/robots.php
*/

#define CENTER 1400
#define CENTER_R CENTER
#define CENTER_L CENTER+1

#define LEFT CENTER-650
#define RIGHT CENTER+650

#define R_FULL_FORWARD R_STOP+300
#define L_FULL_FORWARD L_STOP-300
#define L_FULL_REVERSE R_FULL_FORWARD
#define R_FULL_REVERSE L_FULL_FORWARD
#define R_STOP 1450
#define L_STOP 1450

#define LEFT_TURN 0
#define RIGHT_TURN 1
#define QUARTER_TURN_DELAY 800 // in milliseconds

#define DIST_ERR 50

#define RSPEED R_STOP + 100
#define LSPEED L_STOP – 110

#define DEBUG 0

#define BUMP_DELAY 125

int leftDist = 0; // the average
int rightDist = 0;
int forDist = 0;
int vision = 5;
boolean goingLeft = true;
boolean turnNow = false;

int curDist = 0;
int objDist = 0;
int objDir = 0;

#include .h>

// create servo objects to control servos
ServoTimer2 leftWheel;
ServoTimer2 rightWheel;
ServoTimer2 head;

int leftSpeed = LSPEED; // variable to store the servo position
int rightSpeed = RSPEED;
int headPos=CENTER;

void setup()
{
leftWheel.attach(10); // attaches the servo on pin 9 to the servo object
rightWheel.attach(11);
head.attach(9);

rightWheel.write(rightSpeed); // Stop Wheels
leftWheel.write(leftSpeed); // Stop Wheels
head.write(headPos);

Serial.begin(9600); // initialize serial communication with computer
}

/*******************************************************
* turn – Executes an in-place turn for miliseconds
* QUARTER_TURN_DELAY gets you about 90 deg
********************************************************/
void turn(int dir, int duration){
// Store previous speeds
//rightSpeed = rightWheel.read();
//leftSpeed = leftWheel.read();

if(dir == LEFT_TURN){
rightWheel.write(R_FULL_REVERSE);
leftWheel.write(L_FULL_FORWARD);
}
else {
rightWheel.write(R_FULL_FORWARD);
leftWheel.write(L_FULL_REVERSE);
}
delay(duration);

// restore previous speeds
rightWheel.write(rightSpeed);
leftWheel.write(leftSpeed);
}

void go(){
rightWheel.write(RSPEED);
leftWheel.write(LSPEED);
}

void stop(){
rightWheel.write(R_STOP);
leftWheel.write(L_STOP);
}

/***************************************************
* scan – This function is called every cycle
* it turns the head a click and records a distance and
* heading. It only saves the closest object info.
* objDist and objDir hold the closest object data
****************************************************/
void scan(){

if(goingLeft){
head.write(head.read()-10);
}
else{
head.write(head.read()+10);
}

if(head.read() <= LEFT){
goingLeft = false;
forDist = 0;
objDist = 0;
turnNow = true;
}

if(head.read() >= RIGHT){
goingLeft = true;
forDist = 0;
objDist = 0;
turnNow = true;
}

curDist = analogRead(vision);
if(curDist > objDist){
objDist = curDist;
objDir = head.read();
if(DEBUG){
Serial.print(”New close obj at Dist: “);
Serial.print(objDist);
Serial.print(” heading: “);
Serial.println(objDir);
}
}

delay(10);

}

/**********************************************************
* bump
* Executes a nudge to a given side
* Pass in LEFT_TURN or RIGHT_TURN
***********************************************************/
void bump(int dir){
#define BUMP 100
if(dir == LEFT_TURN){
rightWheel.write(rightWheel.read()-BUMP);
delay(BUMP_DELAY);
rightWheel.write(rightWheel.read()+BUMP);
}
else {
leftWheel.write(leftWheel.read()+BUMP);
delay(BUMP_DELAY);
leftWheel.write(leftWheel.read()-BUMP);
}
}

/**********************************************************
* bumpSteer
* Nudges us back on coarse if we see something off to the
* side. Relies on objDist and objDir to be updated by scan()
*
***********************************************************/
void bumpSteer(){
// One bump per scan
if(!turnNow || objDist < 470)
return;

if(objDir > CENTER){
bump(RIGHT_TURN);
}
else if(objDir <= CENTER){
bump(LEFT_TURN);
}
// No turn till next scan
turnNow = false;
}

void lookAround(){
head.write(LEFT);
delay(400);
leftDist = analogRead(vision);
head.write(CENTER);
delay(400);
forDist = analogRead(vision);
head.write(RIGHT);
delay(400);
rightDist = analogRead(vision);
head.write(CENTER);
delay(200);
}

int cornerNav(){
if(objDist > 600 && objDir > CENTER – 350 && objDir < CENTER + 200){

if( DEBUG ){
Serial.println(“Check:”);
Serial.println(objDist);
Serial.println(objDir);
}

stop();
lookAround();
if(leftDist > rightDist + DIST_ERR){
turn(LEFT_TURN, QUARTER_TURN_DELAY);
}
else {
turn(RIGHT_TURN, QUARTER_TURN_DELAY);
}
go();
objDist = 0;
return 1;
}
return 0;
}

void loop()
{

scan();
if(!cornerNav()){
bumpSteer();
}

}