Understanding Flex Sensors and How to Interface it with Arduino

Flex sensors are versatile components widely used in various applications due to their ability to measure the degree of bending. Essentially functioning as variable resistors, flex sensors have resistance that changes based on the amount of flex they experience, making them ideal for applications such as game controllers, data gloves, motion trackers, and biomedical devices.

Pinout of Flex Sensor:

A typical flex sensor has two pins, labeled P1 and P2, which serve as connection points for retrieving data from the sensor. Unlike some electronic components with specific polarity, such as LEDs, the pins of a flex sensor are interchangeable, allowing either P1 or P2 to be connected to positive or negative terminals without affecting functionality.

How does it work?

Flex sensors come in different sizes, typically 2.2 inches or 4.5 inches long. When in a straight position, the sensor's resistance is approximately 10 kilohms (KΩ), increasing as it bends, reaching a maximum of around 22 KΩ when bent at a 90-degree angle. Constructed with layers of conductive ink protected by a resin substance, bending the sensor causes stretching of the conductive layer, resulting in increased resistance.

Arduino Flex Sensor:

To interface a flex sensor with an Arduino microcontroller, a voltage divider circuit is commonly employed. This circuit consists of the flex sensor and a fixed resistor connected in series. As the flex sensor's resistance changes with bending, the voltage across it also changes. The Arduino's analog-to-digital converter (ADC) can then measure this voltage, allowing the microcontroller to interpret the degree of bending.

Step-by-step guide on interfacing a flex sensor with an Arduino:

• Connect the flex sensor and a fixed resistor in series to form a voltage divider circuit.
• Connect the output of the voltage divider circuit to one of the Arduino's analog input pins.
• Write code for the Arduino to read the analog input and respond accordingly, which may involve mapping the analog input values to specific actions or outputs.

Working of flex sensor module:

A flex sensor operates as a variable resistor that changes its resistance in response to bending. When straight, its resistance is lower, increasing as it bends. This change in resistance is proportional to the degree of bending. By measuring resistance changes, the sensor can detect and quantify flexion accurately. Flex sensors are commonly used in various applications, including game controllers, data gloves, and motion trackers, due to their ability to capture bending movements accurately.

Project ideas using a flex sensor:

• Servo Motor Control using a Flex Sensor
• Raspberry Pi Flex Sensor Interface

In summary, flex sensors offer a simple yet effective way to incorporate bend sensing into electronic projects, making them valuable components in the field of electronics.