Arduino project · Motors and movement · Hard
Three-Servo Arm: Base, Shoulder, Gripper
Three knobs control a robot arm: base turn, shoulder lift and gripper opening.
What you will learn
- How several servos can be controlled at once
- How to limit an angle range
- Why more servos need more power
How it works
Servo 1 can turn the full range. Servo 2 is limited to 30 to 150 degrees so the arm cannot hit the table. Servo 3 is the gripper (0 closed to 90 open).
Try this next
- Add presets with a keypad.
- Add a memory using variables.
- Add a camera on the arm.
The simulator program and explanation on this page are original. The idea follows a classic Arduino project that students have built for years.
Parts: sensors and actuators (tap to show or hide)
Try the inputs (virtual sensors)
Pins (you can change them)
| Part | Arduino pin (change it here) | How to wire it |
|---|
Every wire, one by one
Red rail = 5 V from the Arduino 5V pin. Black rail = GND. The coloured wires carry signals. Match the wire colours on the drawing to this list.
| # | Colour | From (part and leg) | To |
|---|
Steps run from top to bottom, then start again. While the simulation runs, the active step is highlighted in green.
Quantities come from the parts you added. The store links open a search for that item on Robu.in, Amazon.in and ThinkRobotics, so you always see what is in stock today. Check the model, voltage and price before you order.
| # | Item | Qty | Search term | Buy / compare |
|---|
The PDF has the circuit sketch, pin table, every wire, sequence, full code, the parts list with store links, do’s and don’ts for each part, and the safety notes. The project file lets you come back and keep editing.
In the real world
A robot arm with joints
Each servo is one joint of the arm. Move the knobs, keys or joystick and watch the real arm bend.
Tip: use the gold tab at the bottom of the circuit drawing to pull the real-world view up over the Arduino board. Your parts stay visible above it, so you can press a button and watch the real scene react.
- Servo 1, 2 and 3 = the arm joints from the base up