The **HM-10-R** (often referred to in the context of CC2541/CC2540 chips) is a Bluetooth Low Energy (BLE) 4.0 module. The "R" variant usually denotes a specific hardware revision or a firmware version designed for remote control/peripheral applications. Below is an explanation of its core electronic components and specifications. --- ## 1. Core Electronic Components | Component | Description | Function | | :--- | :--- | :--- | | **SoC (System on Chip)** | TI CC2541 or CC2540 | The "brain" containing the 8051 MCU, RF transceiver, and BLE stack. | | **Crystal Oscillator** | 32MHz & 32.768kHz | Provides the clock signal for high-speed operation and low-power sleep modes. | | **Antenna** | PCB Trace Antenna | Integrated inverted-F antenna for 2.4GHz signal transmission. | | **Voltage Regulator** | LDO (Low Dropout) | Drops input voltage (typically 3.6V–6V on breakout boards) to 3.3V. | | **Logic Level Shifter** | Resistor Network/Transistors | Ensures the 3.3V module can communicate with 5V microcontrollers (like Arduino). | --- ## 2. Technical Specifications | Parameter | Specification | | :--- | :--- | | **Bluetooth Version** | Bluetooth V4.0 BLE | | **Working Frequency** | 2.4GHz ISM band | | **Modulation Method** | GFSK (Gaussian Frequency Shift Keying) | | **RF Power** | -23dbm, -6dbm, 0dbm, 6dbm (Adjustable) | | **Sensitivity** | ≤-84dBm at 0.1% BER | | **Supply Voltage** | 3.3V DC (Module) / 5V (Breakout board) | | **Power Consumption** | 0.5mA to 15mA (Active), 50uA to 400uA (Sleep) | --- ## 3. Pinout Definition (Standard 6-Pin Breakout) 1. **VCC**: Power supply (3.6V - 6V). 2. **GND**: Common Ground. 3. **TXD**: Serial Data Out (3.3V Logic). 4. **RXD**: Serial Data In (3.3V Logic). 5. **STATE**: Indicates connection status (Connected = High, Disconnected = Pulsing). 6. **BRK/EN**: Used to wake the module from sleep or reset AT command settings. --- ## 4. Key Features * **AT Commands**: Configured via a serial interface (UART). Common commands include `AT+NAME`, `AT+PASS`, and `AT+ROLE`. * **Master/Slave Support**: Can act as either a central device (connecting to others) or a peripheral (waiting for connections). * **Transparent Transmission**: Once connected, it acts as a wireless serial bridge; data sent to RX appears on the paired device’s screen. ---