Create FPS_Serial_Passthrough.ino

-Adding serial passthrough example code to use with SDK demo software.

Author: bboyho

FPS_GT511C3/Examples/FPS_Serial_Passthrough/FPS_Serial_Passthrough.ino

@@ -0,0 +1,93 @@
+/*****************************************************************
+ * FPS_Serial_Passthrough.ino
+ *
+ *  By: Ho Yun "Bobby" Chan @ SparkFun Electronics
+ *  Date: April 3rd, 2017
+ *  Description: This is a basic serial passthrough code that sets
+ *  up a software serial port to pass data between the Fingerprint Scanner
+ *  and the SDK Demo Software (SDK_Demo.exe) provided by ADH-Tech. This
+ *  code should work with the any model of ADH-Tech's FPS as long as
+ *  you are within the minimum logic level threshold for the FPS serial UART.
+ *  This code has been tested with these models:
+ *
+ *            GT-511C3  [ https://www.sparkfun.com/products/11792 ]
+ *            GT-511C1R [ https://www.sparkfun.com/products/13007 ]
+ *
+ *  A WORD OF CAUTION: It is recommended to use a 3.3V FTDI basic breakout
+ *  board [ https://www.sparkfun.com/products/9873 ] and mini-b USB cable
+ *  [ https://www.sparkfun.com/products/11301 ]. There is a higher
+ *  probability of having problems when using an Arduino as an intermediate device
+ *  between the FPS and your computer. Using the FTDI as the USB-to-serial
+ *  converter is more realiable and easier to get started. Once you have
+ *  enrolled the fingerprints, Hawley's "FPS_IDFinger.ino" code should recognize
+ *  the fingerprint templates saved in memory.
+
+-------------------- HARDWARE HOOKUP with 5V Arduino --------------------
+
+1.) Dedicated Bi-Directional Logic Level Converter (LLC)
+
+It is recommended to use a dedicated bi-direcitonal LLC
+[ https://www.sparkfun.com/products/12009 ] for a reliable connection if you
+are using a 5V Arduino microcontroller:
+
+   Fingerprint Scanner (Pin #) <-> Logic Level Converter <-> 5V Arduino w/ Atmega328P
+     UART_TX (3.3V TTL)(Pin 1) <->     LV4 <-> HV4       <->  RX (pin 4)
+     UART_RX (3.3V TTL)(Pin 2) <->     LV1 <-> HV1       <->  TX (pin 5)
+           GND         (Pin 3) <->     GND <-> GND       <->     GND
+      Vin (3.3V~6V)    (Pin 4) <->        HV             <->      5V
+                                          LV             <->     3.3V
+
+2.) Voltage Division w/ 3x 10kOhm Resistors
+
+Otherwise, you could use 3x 10kOhm resistors [ https://www.sparkfun.com/products/11508 ]
+to divide the voltage from a 5V Arduino down to 3.3V FPS similar to the
+"Uni-Directional" application circuit on our old logic level converter
+[ https://cdn.sparkfun.com/assets/b/0/e/1/0/522637c6757b7f2b228b4568.png ]:
+
+    Voltage Divider         <-> Fingerprint Scanner(Pin #) <-> Voltage Divider <-> 5V Arduino w/ Atmega328P
+                            <-> UART_TX (3.3V TTL) (Pin 1) <->                 <->       RX (pin 4)
+  GND <-> 10kOhm <-> 10kOhm <-> UART_RX (3.3V TTL) (Pin 2) <->      10kOhm     <->       TX (pin 5)
+          GND               <->        GND         (Pin 3) <->       GND       <->        GND
+                            <->    Vin (3.3V~6V)   (Pin 4) <->                 <->        5V
+
+Note: You can add the two 10kOhm resistors in series for 20kOhms. =)
+
+--------------------------------------------------------------------------------
+*****************************************************************/
+
+// We'll use SoftwareSerial to communicate with the FPS:
+#include <SoftwareSerial.h>
+
+// set up software serial pins for Arduino's w/ Atmega328P's
+// FPS (TX) is connected to pin 4 (Arduino's Software RX)
+// FPS (RX) is connected through a converter to pin 5 (Arduino's Software TX)
+SoftwareSerial fps(4, 5); // (Arduino SS_RX = pin 4, Arduino SS_TX = pin 5)
+
+/*If using another Arduino microcontroller, try commenting out line 64 and
+uncommenting line 73 due to the limitations listed in the
+library's note => https://www.arduino.cc/en/Reference/softwareSerial . Do
+not forget to rewire the connection to the Arduino.*/
+
+// FPS (TX) is connected to pin 10 (Arduino's Software RX)
+// FPS (RX) is connected through a converter to pin 11 (Arduino's Software TX)
+//SoftwareSerial fps(10, 11); // (Arduino SS_RX = pin 10, Arduino SS_TX = pin 11)
+
+void setup()
+{
+  // Set up both ports at 9600 baud since that is the FPS's default baud.
+  // Make sure the baud rate matches the config setting of SDK demo software.
+  Serial.begin(9600); //set up Arduino's hardware serial UART
+  fps.begin(9600);    //set up software serial UART for FPS
+}
+
+void loop()
+{
+  if (Serial.available())
+  { // If data comes in from serial monitor, send it out to FPS
+    fps.write(Serial.read());
+  }
+  if (fps.available())
+  { // If data comes in from FPS, send it out to serial monitor
+    Serial.write(fps.read());
+  }
+}