Do you want to learn how to make your own robot? There are many different types of robots, which you can build yourself. Most people want to see a robot do the easy job of moving from point A to B. You can build a robot completely from analog components or buy a starter kit. Making your own robot is a great way to learn electronics and computer programming.
Step
Part 1 of 5: Assembling the Robot
Step 1. Assemble your components
To build a basic robot, you'll need a few simple components. You can find most or all of these components at your local electronics hobby store, or at some online retailers. Some kits include all of these components. This robot does not require any soldering:
- Arduino Uno (or other microcontroller)
- 2 servos 360 degree
- 2 wheels matching servo
- 1 free wheel
- 1 test board (breadboard or project board) that has not been soldered (look for a test board that has two positive and negative rows on each side)
- 1 proximity sensor (with four pin connector cable)
- 1 push button switch
- 1 resistor 10kΩ
- 1 USB A to B cable
- 1 set of breakable headers
- 1 6 x AA battery holder with 9V DC. power socket
- 1 pack of 22. jumper cables or single cable
- Insulation back and forth (double tape) or glue gun
Step 2. Turn the battery compartment so that its flat back is facing up
You will build the robot body using the battery compartment as the base.
Step 3. Arrange two servos facing the same direction at the end of the battery bay
This end is the end where the cable comes out of the battery. The servos should touch the bottom, and the rotation mechanism of each servo should be facing out from the sides of the battery compartment. It is important that these servos are arranged correctly so that the wheels are straight. The cables for the servo must come out of the back of the battery compartment.
Step 4. Glue the servos with your insulation or glue
Make sure that the servo is firmly attached to the battery compartment. The back of the servo must be aligned with the back of the battery compartment.
Now, the servos should take up half the space in the back of the battery bay
Step 5. Adhere the test board perpendicular to the remaining space in the battery compartment
This test board will hang slightly over the front of the battery compartment, and will extend to both sides. Make sure that the test board is tight before proceeding. The “A” row should be closest to the servo.
Step 6. Attach the Arduino microcontroller to the top of the servo
If you attach the servo correctly, there should be a flat part of the two servos touching each other. Adhere the Arduino board to this flat spot so that the USB and Arduino power connectors are facing down (away from the test board). The front of the Arduino will overlap with the test board.
Step 7. Install the wheels on the servos
Firmly press the wheels onto the rotating servo mechanism. This may require considerable force as the wheels are designed to have holes that exactly match the shape of the servo tip.
Step 8. Install the free wheel on the bottom of the test board
If you turn the robot upside down, you'll see a little test board hanging from the battery compartment. Attach the free wheel to this hanging part. Use a wedge if needed. The free wheel serves as the front wheel which allows the robot to turn in any direction with ease.
If you purchased a kit, the free wheel may have some wedges you can use to ensure that the wheel is free to touch the ground
Part 2 of 5: Wiring the Robot
Step 1. Cut two 3-pin headers
You will use this to connect the servo to the test board. Push the pins down through the headers, so they come out an equal distance on both sides.
Step 2. Insert the two headers into pins 1-3 and 6-8 in row E on the test board
Make sure they are inserted firmly or firmly.
Step 3. Connect the servo wires with the header, with the black wire on the left side (pins 1 and 6)
This will connect the servo with the test board. Make sure the left servo is connected to the left header, and the right servo is connected to the right header.
Step 4. Connect the red jumper wire from pins C2 and C7 to the red rail pin (positive)
Make sure you use the red rail on the back of the test board (closer to the rest of the robot body).
Step 5. Connect the black jumper wire from pins B1 and B6 to the blue rail pin (ground)
Make sure you use the blue rail on the back of the test board. Do not attach the cable to the red rail pin.
Step 6. Connect the white jumper wires from pins 12 and 13 on the Arduino to A3 and A8
This will allow the Arduino to control the servo and turn the wheel.
Step 7. Attach the sensor to the front of the test board
The sensor is not mounted to the external power rail on the test board, but to the first two rows of pins lettered (J). Make sure you place it right in the middle with an equal number of empty pins on each side.
Step 8. Connect the black jumper wire from pin I14 to the first blue rail pin on the left of the sensor
This will ground the sensor.
Step 9. Connect the red jumper wire from pin I17 to the first red rail pin on the right of the sensor
This will provide power to the sensor.
Step 10. Connect the white jumper wires from pin I15 to pin 9 on Arduino, and from I16 to pin 8
This will provide information from the sensor to the microcontroller.
Part 3 of 5: Installing the Power Cable
Step 1. Turn the robot over so you can see the battery compartment inside
Arrange the battery compartment so that the cable exits through the bottom left.
Step 2. Connect the red wire with the second spring from the left at the bottom
Make sure that the battery compartment is aligned correctly or is facing the correct direction.
Step 3. Connect the black wire with the last spring on the bottom right
These two wires will help provide proper voltage to the Arduino.
Step 4. Connect the red and black wires to the red and blue pins that are on the right side on the back of the test board
The black wire should go to the blue rail pin on pin 30. The red wire should go to the red rail pin on pin 30.
Step 5. Connect the black wire from the GND pin on the Arduino to the back of the blue rail
Connect the wire to pin 28 on the blue rail.
Step 6. Connect the black wire from the back of the blue rail to the front of the blue rail on pin 29 for both rails
Do not connect the red rail as you may damage the Arduino.
Step 7. Connect the red wire from the front of the red rail on pin 30 to the 5V pin on Arduino
This will provide power to the Arduino.
Step 8. Insert the pushbutton switch in the space between pins 24-26
This switch will allow you to turn off the robot without having to turn off the power.
Step 9. Connect the red wire from H24 to the red rail on the next empty pin to the right of the sensor
This will provide power to the button.
Step 10. Use a resistor to connect H26 to the blue rail
Connect it to the pin directly next to the black wire you just connected in the previous steps.
Step 11. Connect the white wire from G26 to pin 2 on Arduino
This will allow Arduino to detect pushbuttons.
Part 4 of 5: Installing the Arduino Software
Step 1. Download and extract Arduino IDE
This is where Arduino is developed and allows you to program instructions which you can then upload to your Arduino microcontroller. You can download it for free from arduino.cc/en/main/software. Unzip the downloaded file by double-clicking on the file and moving the folder it contains to an easy-to-access location. You won't actually install the program, instead you'll just run it from the folder that was extracted by double-clicking on arduino.exe.
Step 2. Connect the battery compartment to the Arduino
Insert the back socket of the battery into the connector on the Arduino to power it.
Step 3. Insert Arduino into your computer via USB
Chances are, Windows won't recognize the device.
Step 4. Press
Win+R and type devmgmt.msc.
This command will open the Device Manager.
Step 5. Right-click on Unknown device under Other devices and select Update Driver Software
If you don't see this option, click Properties, select the Driver tab, and then click Update Driver.
Step 6. Select Browse my computer for driver software
This will allow you to select the built-in drivers that came with the Arduino IDE.
Step 7. Click Browse, then open the folder you extracted earlier
You will find the drivers folder in it.
Step 8. Select the drivers folder and click OK
Confirm that you want to continue if you are warned about unknown software.
Part 5 of 5: Programming Robots
Step 1. Open ARDUINO IDE by double-clicking on the arduino.exe file in the IDE folder
You will be greeted with a blank project.
Step 2. Paste or paste the following code to make your robot advanced
The code below will keep your Arduino going.
#include // this adds the “Servo” library to the program // the following command creates two servo objects Servo leftMotor; Servo rightMotor; void setup() { leftMotor.attach(12); // if you accidentally swapped the pin numbers for your servo, you can swap the numbers here rightMotor.attach(13); } void loop() { leftMotor.write(180); // with 360 degree rotation (continuous rotation), the number 180 instructs the servo to move “forward” at full speed. rightMotor.write(0); // if both values are 180, the robot will rotate in a circle because the servo is reversed. “0” tells the robot to move “backwards” at full speed. }
Step 3. Create and upload the program
Click the right arrow button in the top left corner to create and upload a program to the connected Arduino.
You may want to lift the robot off the surface as the robot will continue to walk forward after the program is uploaded
Step 4. Add a stop switch function (kill switch)
Add the following code to the "void loop()" section of your code to add a stop switch function on top of the "write()" function.
if(digitalRead(2) == HIGH) // this command runs when the button is pressed on pin 2 Arduino { while(1) { leftMotor.write(90); // "90" is the neutral position for the servo, which tells the servo to stop turning rightMotor.write(90); } }
Step 5. Upload and check your code
With the stop switch code already added, you can upload the code and test the robot. The robot should continue forward until you press the stop switch button which will cause the robot to stop. The full code will look like this:
#include // the following command creates two Servo leftMotor servo objects; Servo rightMotor; void setup() { leftMotor.attach(12); rightMotor.attach(13); } void loop() { if(digitalRead(2) == HIGH) { while(1) { leftMotor.write(90); rightMotor.write(90); } } leftMotor.write(180); rightMotor.write(0); }
Example
The following code will use sensors installed on the robot to make it turn left whenever the robot encounters an obstacle. Look at the comments in the code for details on how to use each part. The code below is the whole program.
#include Servo leftMotor; Servo rightMotor; const int serialPeriod = 250; // this code gives the console output time lag to be every 1/4 second (250 ms) unsigned long timeSerialDelay = 0; const int loopPeriod = 20; // this code sets the sensor reading frequency to 20 ms, which is 50 Hz unsigned long timeLoopDelay = 0; // this code assigns the TRIG and ECHO functions to the pins on the Arduino. Adjust the numbers here if you connect them in a different way const int ultrasonic2TrigPin = 8; const int ultrasonic2EchoPin = 9; int ultrasonic2Distance; int ultrasonic2Duration; // this code defines two possible robot states: continue forward or turn left #define DRIVE_FORWARD 0 #define TURN_LEFT 1 int state = DRIVE_FORWARD; // 0 = continue forward (DEFAULT), 1 = turn left void setup() { Serial.begin(9600); // this sensor determines the pin configuration pinMode(ultrasonic2TrigPin, OUTPUT); pinMode(ultrasonic2EchoPin, INPUT); // this assigns the motor to the Arduino pins leftMotor.attach(12); rightMotor.attach(13); } void loop() { if(digitalRead(2) == HIGH) // this code detects a ''stop'' { while(1) { leftMotor.write(90); rightMotor.write(90); } } debugOutput(); // this code prints debug messages to serial console if(millis() - timeLoopDelay >= loopPeriod) { readUltrasonicSensors(); // this code instructs the sensor to read and store data about the measured distance stateMachine(); timeLoopDelay = millis(); } } void stateMachine() { if(state == DRIVE_FORWARD) // if no obstacle is detected { if(ultrasonic2Distance > 6 || ultrasonic2Distance < 0) // if nothing is in front of the robot. ultrasonicDistance will be negative for some ultrasonics if there are no obstacles { // drive forward rightMotor.write(180); leftMotor.write(0); } else // if there is an object in front of us { state = TURN_LEFT; } } else if(state == TURN_LEFT) // if an obstacle is detected, turn left { unsigned long timeToTurnLeft = 500; // takes about 0.5 seconds to turn 90 degrees. You may need to adjust this value if your wheels differ in size from the size in the example unsigned long turnStartTime = millis(); // save the state when the robot starts to turn while((millis()-turnStartTime) < timeToTurnLeft) // keep this cycle until timeToTurnLeft (500) has passed { // turn left, remember that when both are "180", the robot will turn. rightMotor.write(180); leftMotor.write(180); } state = DRIVE_FORWARD; } } void readUltrasonicSensors() { // this is for ultrasonic 2. You may need to change this command if you are using a different sensor. digitalWrite(ultrasonic2TrigPin, HIGH); delayMicroseconds(10); // pull the TRIG pin high for at least 10 microseconds digitalWrite(ultrasonic2TrigPin, LOW); ultrasonic2Duration = pulseIn(ultrasonic2EchoPin, HIGH); ultrasonic2Distance = (ultrasonic2Duration/2)/29; } // the following is for debugging errors in the console. void debugOutput() { if((millis() - timeSerialDelay) > serialPeriod) { Serial.print("ultrasonic2Distance: "); Serial.print(ultrasonic2Distance); Serial.print("cm"); Serial.println(); timeSerialDelay = millis(); } }
