Hardware Reference
In-Depth Information
Preparing the fingerprint sensor
The fingerprint sensor must be trained to recognize your fingerprint through a process
called
enrollment
. There are several methods to enroll your fingerprint. The SparkFun
website has instructions on how to use the ADH-Tech provided Windows-based software to
program the sensor. However, you'll need an extra component, that is, the FTDI Basic
Breakout board to convert USB from your computer to serial for the scanner. You could
also use an Arduino directly, but you must also use logic level converters if you are using a
5V Arduino. Since the CryptoCape has an Arduino compatible processor, we will show
you how to do this with your BBB and CryptoCape. The repository that contains the AT-
mega firmware can be cloned on your BBB with the following command:
git clone https://github.com/jbdatko/
Fingerprint_Scanner-TTL.git
In this repository, the
FPS_Enroll.ino
file will enroll, or add, a fingerprint to the
sensor's database. As previously mentioned, you'll need to compile this file out of band. Al-
ternatively, you can use the pre-compiled version in the repository above.
Upload the enroll script:
sudo ./upload.sh FPS_Enroll.cpp.hex
You should see text scroll by that looks like this:
Reading | ##################################################
| 100% 0.00s
avrdude: Device signature = 0x1e950f
avrdude: safemode: lfuse reads as 0
avrdude: safemode: hfuse reads as 0
avrdude: safemode: efuse reads as 0
avrdude: NOTE: FLASH memory has been specified, an erase
cycle will be performed
To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "FPS_Enroll.cpp.hex"
avrdude: input file FPS_Enroll.cpp.hex auto detected as
Intel Hex
