How to Use SoftPot Membrane Potentiometer - 50mm: Examples, Pinouts, and Specs

The SoftPot Membrane Potentiometer - 50mm is a versatile and flexible sensor that functions as a variable resistor or potentiometer. Unlike traditional potentiometers, which rely on a rotary or slide mechanism, the SoftPot is a touch-sensitive linear model that can detect position along its 50mm length. This component is ideal for applications requiring a thin and flexible form factor, such as audio mixers, MIDI controllers, robotic interfaces, and custom user interfaces.

• Resistance: 10 kΩ (nominal)
• Active Length: 50mm
• Tolerance: ±20%
• Actuation Force: 0.1 N to 1.0 N
• Life Cycle: >1 million actuations
• Operating Temperature: -40°C to +85°C
• Substrate: Polyester (flexible)
• Power Rating: 0.5 Watts (maximum)

To use the SoftPot Membrane Potentiometer in a circuit, connect pin 1 to a positive voltage source (up to the maximum voltage rating), pin 2 to an analog input on a microcontroller (such as an Arduino UNO), and pin 3 to the ground. The voltage at the wiper (pin 2) will vary linearly with the position of the touch along the active length of the SoftPot.

• Avoid sharp bends or kinks in the SoftPot to prevent damage.
• Ensure that the surface onto which the SoftPot is mounted is clean and smooth.
• Do not press with excessive force to avoid damaging the sensor.
• Use a soft-tipped stylus or finger to actuate the SoftPot.
• Implement software debouncing to account for any noise in the signal.

// Define the pin connected to the SoftPot
const int softPotPin = A0;

void setup() {
  // Initialize serial communication at 9600 baud rate
  Serial.begin(9600);
}

void loop() {
  // Read the analog value from the SoftPot
  int softPotValue = analogRead(softPotPin);
  
  // Map the analog value to a range of 0-100 (percentage of position)
  int position = map(softPotValue, 0, 1023, 0, 100);
  
  // Print the position value to the serial monitor
  Serial.print("Position: ");
  Serial.print(position);
  Serial.println("%");
  
  // Small delay to prevent flooding the serial monitor
  delay(100);
}

• Inconsistent Readings: Ensure that the SoftPot is mounted on a stable, flat surface and that the actuation force is within the specified range.
• No Output Signal: Check the connections to ensure that the SoftPot is properly wired to the voltage source, ground, and the analog input.
• Shortened Life Span: Avoid applying excessive force or sharp objects to the SoftPot surface.

• If you experience jitter in the readings, consider adding a small capacitor (e.g., 10nF) between the wiper (signal) pin and ground to filter out noise.
• For applications requiring more precision, calibrate the SoftPot by reading the maximum and minimum values and using these in the map function in the code.
• When not in use, store the SoftPot in a flat, unstrained position to maintain its longevity.

Q: Can the SoftPot be cut to a shorter length? A: No, cutting the SoftPot will damage the conductive tracks and render it inoperative.

Q: Is the SoftPot waterproof? A: The SoftPot is not waterproof and should be protected from moisture and liquids.

Q: How can I clean the SoftPot? A: Gently wipe the surface with a soft, dry cloth. Do not use harsh chemicals or solvents.

Q: Can I use the SoftPot with a microcontroller other than an Arduino UNO? A: Yes, the SoftPot can be used with any microcontroller that has an analog input. Adjust the code accordingly for the specific platform and programming environment.