arduino robot

Here's my robot based on the arduino diecimila. It's built from two servos modified for continuous rotation, one standard servo and a sharp ir range finder. The body of the robot is a rechargable battery from black and decker called "pocket power". The wheels and "caster" are parts from capcella. The whole thing is assembled with hot glue.

basic function

The robot sweeps the ir range finder 130 degrees and records the closest object. Objects closer than 10 inches will cause the robot to take action. If this object is more than 45 degrees to the right or left it makes a small correction away from the object. If the object is within the center 90 degrees, it stops, looks left and right, finds the clearest direction and turns about 90 degrees to that direction.

Here's a parts list:

item	qty	price
continuous rotation servo	2	13
standard servo	1	10
sharp ir range finder (#)	1	15
black&decker pocket power	1	7.50
misc parts from capsela		0
arduino diecimila	1	38
	total	83.50

The code requires the ServoTimer2 library available here:

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1204020386/74#74

and

http://www.vodkadoctors.at/captFuture/Arduino_balancer/ServoTimer2/

Here is my code for anyone interested:

/* * Micromouse * Brian Bailey * * Drives servo robot and avoids obsticles using Sharp IR range finder * http://bunedoggle.com/robots.php * brian@bunedoggle.com */ #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 <ServoTimer2.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 <duration> 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(); } }

 

rubberband defender arduino robot

Here's my second robot based on the arduino diecimila. Similar to the previous robot it's built on a black&decker pocket power. This time legos have been glued to the battery to allow me to use legos in the construction. A rather crude rubberband gun is attached to the top. The rubber bands are loaded onto the tines of a servo modified for continuous rotation. Each 1/4 turn makes a rubber band fire. Aiming is done with the sharp ir range finder. the robot fires at everything "in range" which I have set to about 15 inches.

And of course the code for those interested. As before this code requires the ServoTimer2 library (links are listed above.)

/* * Rubberband Defender * Brian Bailey * * http://bunedoggle.com/robots.php * brian@bunedoggle.com */ #define STOP 1450 #define LEFT STOP-100 #define RIGHT STOP+100 #define DISTANCE 5 // Analog pin attached to range finder #include <ServoTimer2.h> #undef int #undef abs #undef double #undef float #undef round // create servo objects to control servos ServoTimer2 wheel; ServoTimer2 cannon; ServoTimer2 servo3; void setup() { wheel.attach(9); cannon.attach(10); servo3.attach(11); wheel.write(RIGHT); // Stop Wheels cannon.write(STOP); // Stop Wheels servo3.write(STOP); Serial.begin(9600); // initialize serial communication with computer } void loop() { wheel.write(RIGHT); Serial.print("Dist: "); Serial.println(analogRead(DISTANCE)); if(analogRead(DISTANCE)>=450){ wheel.write(STOP); cannon.write(RIGHT); delay(200); cannon.write(STOP); delay(1500); wheel.write(RIGHT); } }