Use 4 potentiometers (variable resistors) to control your robotic arm by varying the position of potentiometer knob.

What do you need?

• Servo robotic arm
• 4 Potentiometers (2k var)
• Breadboard
• Arduino UNO
• Jumper wires
• Power unit for Arduino

STEP 1: ARDUINO CODE

Upload the code to your arduino.

// Controlling 4 servo motors using 4 separate potentiometers (variable resistor)
// by Servo Robotic Arm <http://www.ServoRoboticArm.wordpress.com&gt;

#include <Servo.h>

Servo myservo; // create servo object to control a servo
Servo ser1;
Servo ser2;
Servo ser3;

int con1 = 0; // analog pin used to connect the potentiometer
int con2 = 1;
int con3 = 2;
int con4 = 3;
int val; // variable to read the value from the analog pin
int val1;
int val2;
int val3;

void setup()
{
myservo.attach(7); // attaches the servo on pin 9 to the servo object
ser1.attach(6);
ser2.attach(5);
ser3.attach(4);
}

void loop()
{
val = analogRead(con1); // reads the value of the potentiometer (value between 0 and 1023)
val = map(val, 0, 1023, 0, 179); // scale it to use it with the servo (value between 0 and 180)
val1 = analogRead(con2);
val1 = map(val1, 0, 1023, 0, 179);
val2 = analogRead(con3);
val2 = map(val2, 0, 1023, 0, 179);\
val3 = analogRead(con4);
val3 = map(val3, 0, 1023, 0, 179);

myservo.write(val); // sets the servo position according to the scaled value
ser1.write(val1);
ser2.write(val2);
ser3.write(val3);
delay(15); // waits for the servo to get there
}

STEP 2: CONNECTION

Connect 4 servo with Arduino and 4 potentiometer as shown in following connection diagram.

Connect:

• 1st terminal of all 4 potentiometers with +5v
• 3rd terminal of all 4 potentiometers with GND
• Middle terminal of potentiometer 1, 2, 3 and 4 with A0, A1, A2 and A3
• Red wire of all 4 servo with +5 v
• Black/Brown wire of all 4 servo with GND
• Yellow wire of gripper micro servo with pin 4
• White wire of right servo with pin 5
•  White wire of center servo with pin 6
• White wire of left servo with pin 7

STEP 3: POWER

Give proper supply to your arduino and control your robotic arm by varying the position of potentiometer knob.

Other method of control: Please note that the robotic arm uses 4 servo, so you can also use any other control method compatible for 4 servo motors.

Link for smartphone/bluetooth controlled servo arm

Link for multi servo control with smartphone

Link for basic introduction to Multiple Servo Control With Joystick

Link for code to control 4 servo with 2 Joystick

Link 2 for code of 4 servo control with 2 joystick

• Double layer robotic chassis
• BO motor (L shape) (2 pcs)
• Wheel (2 pcs)
• Motor driver (1 pcs)

• IR sensor module (2 pcs)
• 9v Battery (3 pcs)
• Battery connector with switch
• Nut-bolt, Screw, Spacer

• Caster (1 pcs)
• Clamp (2 pcs)
• Screw driver
• Foam tape
• 2 female-female jumper wire

Note: Remove brown protective layer form acrylic parts (If any).

STEP-1: Use 3 nut-bolt to fix caster with base acrylic chassis.

STEP-2: Use 2+2 screw to attach clamp with motors.

STEP-3: Mount Motor+Clamp with base acrylic chassis using 2+2 nut-bolt.

STEP-4: Mount upper acrylic plate with base acrylic chassis using 4 spacer and 4 long nut-bolt.

STEP-5: Fix the wheels with motor shaft using 2 small screw.

STEP-6: Stick 2 IR sensor in front side of base acrylic chassis and Motor driver on upper acrylic plate.

STEP-7: Connect motor wire with motor driver as shown in image and stick 3 batteries on upper acrylic plate.

STEP-8: Connect battery connector with 3 batteries. There are 3 Red/White jumper wire and 3 Black/Brown jumper wire at other side of switch, connect these jumper wires as-

Red/White jumper wire with +5v terminal of motor driver.

Black/Brown jumper wire with G terminal of motor driver.

Red/White jumper wire with VCC terminal of IR sensor-1.

Black/Brown jumper wire with GND terminal of IR sensor-1.

Red/White jumper wire with VCC terminal of IR sensor-2.

Black/Brown jumper wire with GND terminal of IR sensor-2.

Connect additional jumper wire with M1a terminal of motor driver and O/P terminal of left side IR sensor.

Connect another jumper wire with M2b terminal of motor driver and O/P terminal of right side IR sensor.

STEP-9: Make a black line (3-4.5 cm) using black tape, put your robot and turn ON the switch.

Troubleshooting:

If the right side wheel+motor rotates in reverse direction then remove the jumper wire from M2b terminal of motor driver and connect it with M2a terminal of motor driver.

Or, If the left side wheel+motor rotates in reverse direction then remove the jumper wire from M1a terminal of motor driver and connect it with M1b terminal of motor driver.

Note: Don’t perform this experiment in direct/partial sun light. Indoor experiment/inside a room is the perfect place for this experiment.

Buy this kit here

Step 1: What do you need

You will require the following items

1. My Arm kit (Acrylic Assembly with 4 DC geared BO motors)
2. 4 Motor-direction-control switch (3 Way, 6 terminal switch)
3. 9v Battery
4. 9v Battery connector
5. 8-core rainbow wire strip (2 mtr.)

MY Arm kit contains all above required items.

Step 2: Connect wire with 4 motors

Connect/solder the 8-core rainbow wire with 4 motors of MY Arm. Each motor have 2 terminals, hence 4 motors have 8 terminals so connect them with 8 wires of rainbow wire strip.

Please note that gripper motor will be little far away from other motors, so the wire you connect with this motor should be longer.

Step 3: Build the ‘My Arm’

Follow the simple instructions described in the assembly manual (provided with every MY Arm kit) to build your ‘MY Arm’.

Step 4: Connections

Connect MY Arm motors, Slide switches and battery as shown in the connection diagram.

Note: You can also use big DPDT switches with same connection diagram and you can also use different battery/power supply according to your project/use. You can use 3 to 9v DC supply/battery. Lower voltage (i.e. 3v DC) will result in slow movement of arm. 6v DC is the best suitable voltage for medium speed and smoother control of MY Arm.