Description
HM-10 Bluetooth Low Energy 4.0 Module
The HM-10 is a Bluetooth Low Energy (BLE) module with a UART interface for wireless communication between a microcontroller and compatible iOS/iPadOS or Android devices. It can be configured in central/master or peripheral/slave roles, depending on the module firmware and AT-command support.
🔧 Listed specifications
- Bluetooth version stated by the listing: Bluetooth 4.0 Low Energy (BLE)
- Radio band: 2.4 GHz ISM
- Modulation: GFSK (Gaussian Frequency Shift Keying)
- Breakout-board input listed: 3.6–6 V; verify the exact board markings before applying power
- UART signal logic: 3.3 V; do not assume every breakout board has level conversion on every signal
- Listed RF output: up to 4 dBm (Class 2)
- Listed receiver sensitivity: up to −84 dBm at 0.1% BER
- Listed range: up to 60 m; this is a seller-stated maximum, not a guaranteed indoor or application range
- Flash memory stated by the listing: 256 Kb
- Current stated by the listing: 0.5 mA in standby and 8.5 mA active; actual consumption depends on board, firmware and radio activity
- Temperature range stated by the listing: −5 to +65 °C
📶 BLE data rate and compatibility
The listing also quotes 2.1 Mbps asynchronous and 1 Mbps synchronous rates. These figures should not be treated as guaranteed application throughput: Bluetooth LE 4.0 uses a 1 Mbps radio PHY, while usable UART/application throughput is lower and depends on firmware, packet size and connection settings. Confirm the specific module revision and firmware.
BLE is not the same as Bluetooth Classic SPP used by modules such as the HC-05. A phone or application must support BLE and the service/characteristics implemented by the module firmware; a generic Bluetooth serial-terminal app may not work with every HM-10 configuration.
⚙️ Power, wiring and setup
Use only the input voltage accepted by the exact breakout board. The underlying HM-10 radio logic uses 3.3 V levels. When connecting a 5 V microcontroller TX output to the module RX input, use a suitable level shifter or divider unless the board documentation confirms that input is protected. Connect grounds together and cross UART TX/RX.
Configure baud rate, role, advertising and BLE service settings using the commands supported by the supplied firmware. Clone modules may use different chips, firmware, AT commands or pin arrangements even when sold as “HM-10.” Test the required pairing and data exchange with the intended phone or controller before integrating it into a project.
The listing mentions authentication/encryption and automatic sleep. Availability and behavior depend on the actual firmware and configuration; verify security and power-saving behavior rather than assuming they are enabled.
💡 Typical uses
- BLE sensor-data prototypes
- Wireless UART-style communication with a BLE-capable app
- Microcontroller projects using a phone or tablet interface
- Low-power Bluetooth experiments with compatible devices
