Template: Capacitive Fingerprint Reader B Pi guide

For Development boards like the Raspberry Pi, Arduino, STM32, only the UART interface is supported.

Connection

Fingerprint Reader (B)	Raspberry Pi	Description
VCC	3.3V	Power input
GND	GND	Ground
TXD	RXD	UART data output
RXD	TXD	UART data input
RST	GPIO5	Reset pin (low active)

Enable the Serial port of Pi

• Open the terminal of the Raspberry Pi
• Type command sudo raspi-config
• Choose Interface Options -> Serial -> No -> Yes
• Disabled the login shell function and enable the hardware serial port.

Download the demo codes

Open the terminal of the Raspberry Pi and run the following commands.

cd
wget https://www.waveshare.com/w/upload/e/e3/Capacitive-Fingerprint-Reader-B-Code.zip
unzip Capacitive-Fingerprint-Reader-B-Code.zip
cd Capacitive-Fingerprint-Reader-B-Code/

Install Libraries

• Install wiringpi

sudo apt-get install wiringpi
# An upgrade may be required for raspberry PI 4B:
cd /tmp
wget https://project-downloads.drogon.net/wiringpi-latest.deb
sudo dpkg -i wiringpi-latest.deb
gpio -v
# Running gpio-v to check if the version is 2.52, If it is not, you need to check the installation again.

• BCM2835 library:

wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.60.tar.gz
sudo tar zxvf bcm2835-1.60.tar.gz
cd bcm2835-1.xx
sudo ./configure
make
sudo make check
sudo make install

Note: You can also go to http://www.airspayce.com/mikem/bcm2835/index.html for newest libraries.

• Install the python2 library

sudo apt-get update
sudo apt-get install python-pip
sudo pip install RPi.GPIO
sudo apt-get install python-serial

• Install the python3 library

sudo apt-get update
sudo apt-get install python3-pip
sudo pip3 install RPi.GPIO
sudo apt-get install python3-serial

Testing the example

Open the terminal of the Raspberry Pi and run the following commands.

C example

cd ~/Capacitive-Fingerprint-Reader-B-Code/RaspberryPi/c
sudo make
sudo ./test

python example

cd ~/Capacitive-Fingerprint-Reader-B-Code/RaspberryPi/Python
sudo python main.py

python3 example

cd ~/Capacitive-Fingerprint-Reader-B-Code/RaspberryPi/Python3
sudo python3 main.py

After running the example, the prompt printed in the terminal, you need to type the defined commands to enable the testing function:

• CMD0:

Check if the fingerprint is connected normally

• CMD1:

Check if a finger is detected

• CMD2:

Add a fingerprint

• CMD3:

Detect fingerprints

• CMD4:

Verify fingerprint (1:1)

• CMD5:

Verify fingerprints

• CMD6:

Check the ID which is not be used (minimum number)

• CMD7:

Check the number of fingerprinted added

• CMD8:

Upload a fingerprint image to the host from the Fingerprint Reader

• CMD9:

Download a fingerprint image to the Fingerprint Reader from the host