Overview of Flex Sensor
Flex sensors are a type of variable resistor that changes its resistance when bent or flexed. This makes them ideal for use in Arduino projects, as they can be used to measure physical movement and changes in the environment. The resistance range of a flex sensor varies depending on the size and type, but typically ranges from 10 to 100 kilo ohms.
Connecting the Flex Sensor to the Arduino
The Arduino is unable to measure resistance directly; instead, it can measure a changing voltage. To measure the resistance change of the flex sensor, a voltage divider circuit must be built. This involves connecting the flex sensor in series with another resistor. The exact value of the resistor will depend on the resistance range of the flex sensor, but should be in the 10 to 100 kilo ohm range.
Using a Multimeter to Measure Resistance
A multimeter can be used to measure the resistance of the flex sensor. To do this, the multimeter should be set to measure resistance in the 200 kilo ohm range. When the flex sensor is straight, the resistance should be around 26 or 27 kilo ohms. When the flex sensor is bent 180 degrees, the resistance should increase to over 100 kilo ohms.
Using Tinkercad Circuits to Simulate the Arduino
Tinkercad Circuits is a free online Arduino simulator that allows users to see the circuit and code side by side. This is a useful tool for testing the flex sensor and voltage divider circuit before connecting it to the Arduino. There is a separate tutorial video about Tinkercad Circuits available in the description of this video in the Arduino playlist.
Flex Sensor and Arduino
The flex sensor is a device that is used to measure the bending of an object. It is composed of a resistive element that changes its resistance when bent. This change in resistance is then measured by an Arduino to determine the degree of bending.
Voltage Divider Circuit
In order to measure the resistance of the flex sensor, a voltage divider circuit must be created. This circuit consists of the flex sensor and a resistor connected in series between the 5V pin of the Arduino and ground. The output of the voltage divider is connected to one of the Arduino’s analog inputs. As the flex sensor bends, the resistance of the flex sensor changes, which in turn changes the voltage at the output of the voltage divider.
Reading the Voltage
The Arduino can then read the voltage at the output of the voltage divider using the analogRead() command. This command takes an analog input pin as an argument and returns the voltage at that pin as an integer between 0 and 1023. The voltage can then be used to calculate the degree of bending of the flex sensor.
LEDs
In addition to reading the voltage from the flex sensor, the Arduino can also be used to control LEDs. This can be done by connecting the LEDs to digital output pins of the Arduino and using the digitalWrite() command to set the pins to either HIGH or LOW. This will turn the LEDs on or off depending on the value of the digital output pin.
Declaring Variables
When using a flex sensor with an Arduino, the first step is to declare the necessary variables. This includes a variable for the sensor pin, and another for the sensor reading. Additionally, variables need to be declared for all of the LED pins.
Setup Function
In the setup function, the LED pins are configured as outputs using the pin mode command. Serial communication is also initialized, allowing the sensor readings to be viewed in the serial monitor.
Loop Function
The loop function reads the sensor value using the analog, read command and prints the variable to the serial monitor. This is useful for calibrating the sensor and determining the appropriate thresholds for activating certain functions.
Example
As an example, this tutorial will demonstrate how to control a series of five LEDs. When the sensor is bent far enough, all five LEDs will be turned on. As the value gets lower, fewer LEDs will be activated. This is achieved through a series of if statements with different threshold levels.
Sciencebuddies.org
Understanding Flex Sensors
Flex sensors are a type of resistive sensor that changes its resistance when bent. They are commonly used in robotics and other engineering projects to detect motion or position. The resistance of the flex sensor increases when it is bent in one direction and decreases when bent in the opposite direction. This makes it ideal for detecting movement or position in a variety of applications.
Using Flex Sensors with an Arduino
Using a flex sensor with an Arduino is relatively straightforward. The Arduino can not read resistance changes directly, so a voltage divider circuit must be set up. This involves connecting a large value external resistor in series with the flex sensor and then reading the middle pin of the voltage divider on one of the Arduino’s analog input pins. The analog read function can then be used to read the voltage on the pin and determine the resistance of the flex sensor.
Controlling LEDs with a Flex Sensor
Once the Arduino is able to read the resistance of the flex sensor, it can be used to control LEDs. This involves setting up a series of if statements that turn on the LEDs when the flex sensor reaches certain thresholds. For example, if the value is below 300, then none of the LEDs are on. If the value is between 300 and 500, then one LED is on. If the value is between 500 and 700, then two LEDs are on, and so on. Some trial and error with bending the sensor and looking at the output in the serial monitor is necessary to determine the thresholds for the if statements.
Flex sensors are a type of variable resistor that can be used in Arduino projects to measure physical movement and changes in the environment. To measure the resistance change of the flex sensor, a voltage divider circuit must be built by connecting the flex sensor in series with another resistor. A multimeter can be used to measure the resistance of the flex sensor, and Tinkercad Circuits can be used to simulate the Arduino before connecting the flex sensor.
Using a flex sensor with an Arduino is a simple and effective way to measure the degree of bending of an object. By connecting the flex sensor to a voltage divider circuit and reading the voltage at the output of the voltage divider, the Arduino can measure the degree of bending. Additionally, the Arduino can be used to control LEDs based on the degree of bending.
Using a flex sensor with an Arduino is a relatively simple process. By declaring the necessary variables, configuring the LED pins as outputs, and utilizing if statements with different threshold levels, users can control a series of LEDs or other functions.
Flex sensors are a useful tool for detecting motion or position in robotics and other engineering projects. They can be used with an Arduino by setting up a voltage divider circuit and using the analog read function to read the voltage on the pin. The Arduino can then be used to control LEDs by setting up a series of if statements that turn on the LEDs when the flex sensor reaches certain thresholds.
