Arduino project · Motors and movement · Easy
Flex Sensor Controls a Servo
Bend the flex sensor and the servo follows, like a robot finger.
What you will learn
- How a flex sensor changes its resistance
- How to read it with a voltage divider
- How to turn bending into a servo angle
How it works
The flex sensor and a 10k resistor form a voltage divider. More bend gives a different voltage, which the Arduino reads as 0 to 100 %. The map step turns it into 0 to 180 degrees for the servo.
Try this next
- Glue the flex sensor on a glove.
- Control a second servo with another sensor.
- Add an LED for a bend limit.
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 servo arm
The servo turns an arm to the angle you set. The angle is shown under the arm.
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 = the motor that turns the arm