Code

// Include Libraries
#include "Arduino.h"
#include "FSR.h"
// Pin Definitions
#define FSR_PIN_1	A3
// Global variables and defines
// object initialization
FSR fsr(FSR_PIN_1);
// define vars for testing menu
const int timeout = 10000;       //define timeout of 10 sec
char menuOption = 0;
long time0;
// Setup the essentials for your circuit to work. It runs first every time your circuit is powered with electricity.
void setup() 
{
    // Setup Serial which is useful for debugging
    // Use the Serial Monitor to view printed messages
    Serial.begin(9600);
    while (!Serial) ; // wait for serial port to connect. Needed for native USB
    Serial.println("start");
    menuOption = menu();
}
// Main logic of your circuit. It defines the interaction between the components you selected. After setup, it runs over and over again, in an eternal loop.
void loop() 
{
    if(menuOption == '1') {
    // Force Sensitive Resistor 0.5'' - Test Code
    // Read FSR resistance value. try also fsr.getResistance()
    // For more information see Sparkfun website - www.sparkfun.com/products/9375
    // Note, the default Vcc and external resistor values for FSR calculations are 5V ang 3300Okm, if you are not 
    //       using these default valuse in your circuit go to FSR.cpp and change default values in FSR constructor
    float fsrForce = fsr.getForce();
    Serial.print(F("Force: ")); Serial.print(fsrForce); Serial.println(F(" [g]"));
    }
    if (millis() - time0 > timeout)
    {
        menuOption = menu();
    }
}
// Menu function for selecting the components to be tested
// Follow serial monitor for instrcutions
char menu()
{
    Serial.println(F("\nWhich component would you like to test?"));
    Serial.println(F("(1) Force Sensitive Resistor 0.5''"));
    Serial.println(F("(menu) send anything else or press on board reset button\n"));
    while (!Serial.available());
    // Read data from serial monitor if received
    while (Serial.available()) 
    {
        char c = Serial.read();
        if (isAlphaNumeric(c)) 
        {              
            if(c == '1') 
    			Serial.println(F("Now Testing Force Sensitive Resistor 0.5''"));
            else
            {
                Serial.println(F("illegal input!"));
                return 0;
            }
            time0 = millis();
            return c;
        }
    }
}