r307 Fingerprint Sensor Module on ESP32

The Following Code is a Library for interfacing r307 Fingerprint Module with ESP32 on Embedded C Language

GPIO Functions:

ESP32 Devkit v1	r307 Fingerprint Sensor
VIN pin	Pin 1
GND pin	Pin 2
GPIO 16	Pin 3
GPIO 17	Pin 4

• Pin 5 and Pin 6 of the sensor can be opened ( No Connection )

Connection Diagram:

Understanding the Flow:

• This code is developed for ESP32 on Embedded C Language.
• There are 2 files you need to import which are going to be the library for interfacing ESP32 with R307 Sensor Module.
• R307 Fingerprint Sensor by default runs on UART Baud : 57600, with 8 data bits, 1 stop bit and no partiy.
• Once "r307_init()" is called, that shall initialize UART ESP32 with the set parameters.
• Further there are 3 sections for the following library :
  • check_sum()
  • r307_reponse()
  • r307_response_parser()
• The check_sum() performs checksum modulo 256 on Package Identifier, Package Length, Instruction Code and ( if used ) Packet Data like new address, new password, etc.
• r307_reponse() function is responsible to receive package responses sent via the sensor module to ESP32.
• Lastly, r307_response_parser() function has the prime role of parsing every response received from the fingerprint sensor.
• There are several functions involved, total 22 for this library currently, that perform various tasks like setting new module address & new module password, reading system parameters, capturing or verifying or storing finger, etc.
• All these functions are written as per their names given in the user manual for r307 fingerprint module.
• Last but not the least, this repo is a library and doesn't have any example codes yet although every component you need to build a program for yourself can be easily done as comments and briefing is done for every code of line used.
• Please note, everytime you use any function to perform a task, you will have to provide the 32-bits Module address ( Default Address : 0xFF, 0xFF, 0xFF, 0xFF & Default Password : 0x00, 0x00, 0x00, 0x00 )
• Also note that any extra packet data if being used has to be declared in an char array with hex values as the data.

Conclusion:

• Interfacing ESP32 with r307 Fingerprint Sensor wasn't the easiest or the most difficult but I did encountered lot of odds to develop the library on C as whole of the internet happens to use Arduino IDE.
• Examples codes are not yet available, but if I work on them in future then will surely commit the same.
• There are two functions missing : "WriteNotepad" & "ReadNotepad". I tried but couldn't crack them, so will commit the same whenever possible in future.
• Do share with others and I hope you all like it :-D

Reference Material:

• https://www.openhacks.com/uploadsproductos/r307_fingerprint_module_user_manual.pdf