Hardware Overview
Let's take a closer look at the FPC2534 sensor and other hardware on this Qwiic breakout.
FPC2534 Fingerprint Sensor
The FPC2534 fingerprint sensor is a compact fingerprint sensor capable of enrolling and storing up to 45 fingerprint templates and also has a four-way navigation feature. The FPC2534 has a low-profile design that includes a hidden bezel tied to four ground pins. It communicates over UART, I2C, SPI and USB. It runs best powered with 3.3V with a max current draw of ~21mA during active mode. For complete information on the FPC2534, refer to the datasheet.
The sensor automatically creates and stores fingerprint templates as they are added in the device's flash memory. The FPC2534 also supports encrypted communication with a host device though this feature must be enabled by sending an AES key from the host to the FPC2534. For more information on enabling this feature, refer to the Supplemental Information document.
Connectors and Pinout
USB-C
The board has a USB-C connector to use the FPC2534 over its USB interface. The 5V supply voltage from USB is regulated down to 3.3V to safely power the FPC2534 over USB.
Qwiic
The pair of Qwiic connectors on the board . Note, communicating with the FPC2534 over I2C requires connecting the Interrupt Request (IRQ) pin to the host microcontroller.
PTHs and Bezel Mounts
The board has a pair of 0.1"-spaced plated through-hole (PTH) headers that break out a majority of the FPC2534's pins.
We've also plated all four mounting holes and connected them to the board's ground bezel for optimal performance.
LEDs
This board has a pair of LEDs labeled PWR and Scan. The red PWR LED indicates whenever the board has power. The green Scan LED is software controlled and tied to GPIO1 on the FPC2534.
Solder Jumpers
There are five solder jumpers on this board labeled: CFG1, CFG2, I2C, LED and BZL. The list below outlines their functionality, default states and any notes on their use.
- I2C - Pulls the FPC2534's I2C lines (SDA/SCL) to 3.3V through a pair of 2.2kΩ resistors. This jumper is CLOSED by default. Open it to disable pullups on these lines.
- LED - This jumper completes the Power LED circuit and is CLOSED by default. Open the jumper to disable the power LED.
- BZL - This jumper ties the FPC2534's bezel ground plane to the sensor's main ground and is CLOSED by default. Open this jumper to isolate the bezel ground from the main ground plane.
- CFG1 & CFG2 - These two jumpers control the interface selection for the FPC2534. The table below outlines the interface options and their corresponding jumper states:
| Interface | CFG1 | CFG2 |
|---|---|---|
| I2C (Default) | CLOSED | CLOSED |
| USB | OPEN | CLOSED |
| UART | CLOSED | OPEN |
| SPI | OPEN | OPEN |
Board Dimensions
The SparkFun Fingerprint Sensor - FC2534 (Qwiic) matches the 1"x1" (25.4mm x 25.4mm) and has four mounting holes that fit a 4-40 screw. Note, all four of the mounting holes are plated to allow users to ground the board to their mount through these holes.
