Added code used for FlexiForce mass estimation using the linear interpolation.

Interpolation_FlexiForce_Estimation/Interpolation_FlexiForce_Estimation.ino

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+/**
+ * @file    Interpolation_FlexiForce_Estimation.ino
+ * @author  Charles STELANDRE
+ * @version V0.1
+ * @date    2025/05/11
+ * @brief   Description: this code estimates the mass from a FlexiForce A201 sensor.
+ *          First, you must record the signal within a range of [0-5]V, and the mass put on the sensor
+ *          Second, you must report this data in the calibrationData. You must do so in an ascending order.
+ *          Test the full range. Masses outside of the range you tested may not give the required result.
+ *          
+ *
+ * Function List:
+ * 1. double getVoltage(int rawValue)
+ * 2. double getMass(double voltage)
+ * 3. void setup()
+ * 4. void loop()
+ */
+ 
+#include <Servo.h>
+
+Servo myServo;  // Create a servo object
+const int sensorPin = A0; // Analog pin for the weight sensor
+const int servoPin = 9;  // Digital pin for the servo
+
+// Calibration data: {voltage_in_V, mass_in_grams}
+//Enter your calibration data here.
+double calibrationData[][2] = {
+  {1.776, 500},
+  {3.288, 200},
+  {4.076, 100},
+  {4.530, 50},
+  {4.824, 20},
+  {4.924, 10},
+  {4.92, 0},
+};
+const int calibrationDataSize = sizeof(calibrationData) / sizeof(calibrationData[0]);
+
+// Function to convert raw analog reading (0-1023) to voltage (0-5V)
+double getVoltage(int rawValue) {
+  return (rawValue * 5.0) / 1023.0;
+}
+
+// Function to map the sensor voltage to mass in grams using linear interpolation
+double getMass(double voltage) {
+  if (voltage <= calibrationData[0][0]) {
+    return calibrationData[0][1];
+  }
+  if (voltage >= calibrationData[calibrationDataSize - 1][0]) {
+    return calibrationData[calibrationDataSize - 1][1];
+  }
+
+  for (int i = 0; i < calibrationDataSize - 1; i++) {
+    if (voltage >= calibrationData[i][0] && voltage < calibrationData[i + 1][0]) {
+      return calibrationData[i][1] + (voltage - calibrationData[i][0]) *
+             (calibrationData[i + 1][1] - calibrationData[i][1]) /
+             (calibrationData[i + 1][0] - calibrationData[i][0]);
+    }
+  }
+  return -1; // Should not happen if data is sorted
+}
+
+// Function to map the mass (0-500g initially, scaling to 5kg later) to servo angle (0-180 degrees)
+int massToAngle(double mass) {
+  // Assuming the servo has a 180-degree range (can increase to show when out of range).
+  // We'll map the current tested range (0-500g) to the full servo range.
+  // Once you have data up to 5kg, you might need to adjust this mapping.
+  return map(mass, 0, 500, 0, 180); // Change 0 and 500 to your calibration points' limits if needed
+}
+
+void setup() {
+  Serial.begin(9600);
+  myServo.attach(servoPin); // Attaches the servo on pin 9 to the servo object
+  Serial.println("Weight Sensor Test Sketch (Voltage Input)");
+}
+
+void loop() {
+  int rawValue = analogRead(sensorPin);
+  double currentVoltage = getVoltage(rawValue);
+  double currentMass = getMass(currentVoltage);
+
+  Serial.print("Raw Sensor Value: ");
+  Serial.print(rawValue);
+  Serial.print(" | Voltage: ");
+  Serial.print(currentVoltage);
+  Serial.print(" V | Estimated Mass: ");
+  Serial.print(currentMass);
+  Serial.println(" g");
+
+  if (currentMass != -1) {
+    int servoAngle = massToAngle(currentMass);
+    servoAngle = constrain(servoAngle, 0, 180); // Ensure the angle is within the servo's limits
+    myServo.write(servoAngle);
+    Serial.print("Servo Angle: ");
+    Serial.println(servoAngle);
+  } else {
+    Serial.println("Error: Sensor voltage out of calibration range.");
+  }
+
+  delay(100); // Adjust delay as needed
+}