 void loop()                     // run over and over again
 {
   Serial.println("Type in the ID # you want to save this finger as...");
-  uint8_t id = 0;
+  int id = 0;
   while (true) {
     while (! Serial.available());
     char c = Serial.read();

#include <Adafruit_Fingerprint.h>
#include <SoftwareSerial.h>

uint8_t getFingerprintEnroll(uint8_t id);


// pin #2 is IN from sensor (GREEN wire)

  while (!  getFingerprintEnroll(id) );
}

uint8_t getFingerprintEnroll(int id) {
  int p = -1;
  Serial.println("Waiting for valid finger to enroll");
  while (p != FINGERPRINT_OK) {
    p = finger.getImage();
