The **FPM3252H-R010CFR** is a high-performance, optical fingerprint recognition module. It belongs to the FPM series, typically utilized for biometric security applications such as door locks, safes, and attendance systems. --- ### ## Technical Specifications Overview Below are the core electronic characteristics of the module: | Parameter | Specification | | :--- | :--- | | **Sensor Type** | Optical CMOS Sensor | | **Resolution** | 508 DPI | | **Supply Voltage (VDD)** | 3.3V to 5.0V DC | | **Operating Current** | < 100mA (Peak) | | **Interface** | UART (TTL) / USB 1.1/2.0 | | **Matching Mode** | 1:1 and 1:N | | **Baud Rate** | 9600 to 115200 bps (Default 57600) | | **Storage Capacity** | Typically 500 to 1000 templates | --- ### ### Key Electronic Components The module functions as a "System on a Chip" (SoC) integration, consisting of three primary electronic layers: 1. **Optical Imaging System:** * **Light Source:** Integrated high-efficiency LEDs (usually blue or green) that illuminate the fingerprint ridges. * **Prism/Lens:** Directs the reflected light from the finger onto the CMOS image sensor. 2. **CMOS Image Sensor:** * Converts the optical image of the fingerprint into a digital signal (grayscale map). 3. **Digital Signal Processor (DSP):** * The "brain" of the module. It runs the onboard algorithm to perform feature extraction, template generation, and matching. * It handles the communication protocols (UART/USB) to talk to external microcontrollers (like Arduino or STM32). --- ### ### Pinout Configuration The module usually features a 6-pin connector (1.25mm pitch). The typical wiring is as follows: | Pin | Name | Description | | :--- | :--- | :--- | | 1 | **VCC** | Power Input (3.3V - 5V) | | 2 | **GND** | Ground | | 3 | **TXD** | Data Output (Connect to MCU RX) | | 4 | **RXD** | Data Input (Connect to MCU TX) | | 5 | **IRQ** | Interrupt pin (High when finger is detected) | | 6 | **V-Touch** | Touch sensing power (Optional) | --- ### ### Logic Level & Interfacing ```cpp // Typical Arduino Connection Example // FPM3252H TX -> Arduino Pin 2 (SoftwareSerial RX) // FPM3252H RX -> Arduino Pin 3 (SoftwareSerial TX) // VCC -> 5V // GND -> GND #include SoftwareSerial mySerial(2, 3); // RX, TX void setup() { Serial.begin(9600); mySerial.begin(57600); // Default baud for FPM series Serial.println("Fingerprint module testing..."); } ``` --- ### ### Safety and Operational Considerations * **ESD Protection:** The sensor surface is sensitive to static electricity. Ensure proper grounding during installation. * **Voltage Logic:** While the VCC may accept 5V, the UART logic is often 3.3V. Use a logic level shifter if connecting to a 5V MCU to prevent long-term degradation. * **Power Consumption:** The module consumes significant current during the "scanning" phase; ensure your power supply can handle 100mA+ spikes.