Programmable Omni Direction Robotic Arm Vehicle

Programmable Omni Direction Robotic Arm Vehicle

How It Works

• Four Mecanum wheels, each independently driven, let the base translate forward/back, strafe sideways, and rotate in place — or combine all three for diagonal movement — purely by varying each wheel's speed and direction.
• An HC-05 Bluetooth module receives directional and joint-angle commands from a paired Android app, which the controller maps to motor driver signals (base movement) and servo positions (arm joints and gripper).
• In manual mode, the operator drives the base into position and jogs the arm/gripper directly from the app to pick up and place an object.
• In program mode, each manual step (a base move, a joint angle, a gripper open/close) is logged as a sequence in memory; on playback, the controller replays that exact sequence of moves automatically, repeating the same pick-and-place cycle without operator input.

Components

Arduino Mega (extra I/O for 4 wheel motors + 4 arm servos)
Bluetooth module (HC-05)
4x Mecanum wheels + DC gear motors
Dual motor driver modules (L298N or BTS7960) for 4-wheel independent drive
4x servo motors (arm base, shoulder, elbow, gripper)
Android app (App Inventor or custom BLE app) for control
Li-ion/LiPo battery pack
Chassis frame + arm linkage assembly

Applications

• Pick-and-place automation on conveyor lines
• Warehouse material handling and component transfer
• Educational robotics — teaching omnidirectional kinematics and servo control
• Prototype workstation-side part loading

Advantages

• Omnidirectional movement allows precise positioning without repeated turning
• Manual and programmed playback modes in one platform
• Reduces operator fatigue on repetitive transfer tasks once a sequence is recorded
• 4-DOF arm is enough for most small pick-and-place tasks while staying simple to control from a phone

Sample Code — Bluetooth Direction & Servo Command Parser

// Simplified Bluetooth command parser — Arduino
// Commands from Android app: 'F','B','L','R','S' (base) and 'J1:90' style for joints
#include 
Servo base, shoulder, elbow, gripper;

void setup() {
  Serial.begin(9600); // HC-05 on Serial
  base.attach(3); shoulder.attach(5); elbow.attach(6); gripper.attach(9);
}

void driveBase(char cmd) {
  switch (cmd) {
    case 'F': /* all 4 wheels forward */ break;
    case 'B': /* all 4 wheels reverse */ break;
    case 'L': /* strafe left - Mecanum mix */ break;
    case 'R': /* strafe right - Mecanum mix */ break;
    case 'S': /* stop all wheels */ break;
  }
}

void loop() {
  if (Serial.available()) {
    String cmd = Serial.readStringUntil('\n');
    if (cmd.startsWith("J1:")) base.write(cmd.substring(3).toInt());
    else if (cmd.startsWith("J2:")) shoulder.write(cmd.substring(3).toInt());
    else if (cmd.startsWith("J3:")) elbow.write(cmd.substring(3).toInt());
    else if (cmd.startsWith("G:")) gripper.write(cmd.substring(2).toInt());
    else if (cmd.length() == 1) driveBase(cmd[0]);
  }
}

Related Research

• Design and Implementation of Omnidirectional Mobile Robot for Materials Handling among Multiple Workstations in Manufacturing Factories — MDPI Electronics