The BL12-A3 is a Bluetooth audio receiver module frequently integrated into smart home accessories, most notably LED bathroom mirrors with built-in speakers. Core Functionality
The module acts as a wireless bridge between a smartphone or laptop and an external speaker system.
Pairing Name: When searching for devices on your mobile, the module typically appears as "BL12-A3".
Connection Feedback: Upon a successful connection, the module usually emits an audible chime or sound to confirm it is ready to play music. bl12a3 bluetooth full
Media Control: Once paired, users can play, pause, or skip tracks directly from their handheld device. Technical Specifications
While often part of a larger assembly, the general technical characteristics for systems using this module include: Power Supply: Typically requires a 12V DC input.
Audio Output: Commonly paired with dual active speakers (e.g., 3W or 5W each) providing a frequency range of approximately 100Hz–20kHz. The BL12-A3 is a Bluetooth audio receiver module
Transmission Range: Supports wireless streaming at distances up to 30 feet (approx. 10 meters) without obstacles.
Safety Rating: In bathroom mirror applications, the associated hardware often carries an IP44 rating for protection against splashes. Usage in Smart Mirrors
In products like those from Artforma, the module is activated via a touch sensor on the mirror face. Holding the sensor for about 3 seconds typically turns the power on, indicated by the button turning white. Bluetooth Speaker - Artforma Note: Always verify the specific revision with your vendor
Understanding the raw specifications is critical for hardware integration. Below is a typical datasheet summary for the BL12A3 (Bluetooth 2.1 variant):
| Parameter | Value | |-----------|-------| | Bluetooth Version | 2.0 + EDR or 2.1 + EDR (backward compatible with 1.2) | | Frequency Band | 2.4 GHz ISM (2402–2480 MHz) | | Modulation | GFSK (Gaussian Frequency Shift Keying) | | RF Power (Class 2) | -6 dBm to +4 dBm (typical 0 dBm) | | Receive Sensitivity | -80 dBm to -85 dBm (depending on vendor) | | Data Rate (UART) | 9600 bps to 1.3824 Mbps (default 9600, 8N1) | | Air Data Rate | Up to 2.1 Mbps (EDR) | | Operating Voltage | 3.0V – 3.6V (absolute max 3.9V, not 5V tolerant) | | Current Consumption | Tx: ~30 mA, Rx: ~25 mA, Standby: < 1 mA (Deep sleep: < 10 µA for BLE variant) | | Interface | UART (TX, RX, RTS, CTS optional), GPIO, State LED | | Antenna | On-board PCB trace antenna (gain ~1 dBi) | | Range (LOS) | 10 meters (typical indoor), up to 20 meters (open field) | | Form Factor | 27 mm x 13 mm x 2.5 mm (typical) | | Pin Pitch | 2.54 mm (compatible with breadboards and 0.1" headers) |
Note: Always verify the specific revision with your vendor. Some “BL12A3” modules sold online use a BLE-only chip (e.g., based on TI CC2541 or Telink), which will have different power and command set characteristics.
AT followed by \r\n. Verify KEY is >3.0V.With Bluetooth 5.3 and LE Audio on the rise, is an inexpensive 5.0 module still worth buying? Yes. Here is why:
The BL12A3 will likely remain a staple for hobbyists for another 3–5 years because it solves a simple problem efficiently: making dumb speakers smart.
