DC 12V 8-Channel Bluetooth Relay Module for Smart Home Control
DC 12V 8-Channel Bluetooth Relay Module for Smart Home Control
DC 12V 8-Channel Bluetooth Relay Module — Wireless Smart Home Control
Take full command of your smart home setup with the BT21A08 DC 12V 8-Channel Bluetooth Relay Module. Designed for seamless wireless integration, this relay controller lets you switch lights, LED strips, appliances, and more directly from your Android smartphone — no complicated wiring or hub required. Made in Mainland China.
Key Features
- 8 Independent Relay Channels — control up to 8 separate circuits from one compact module
- Bluetooth 2.1 Wireless Control — operate via the included Bluetooth app or integrate with your own custom app using simple serial commands
- Wide Control Voltage Range — supports AC 85–265V / 10A and DC 1–110V / 10A, making it compatible with most home electrical systems
- Flexible Relay Modes — supports momentary (point), self-locking, and interlock modes; each relay features normally-open (NO) and normally-closed (NC) contacts
- Customizable Bluetooth Settings — rename the Bluetooth device and change the connection password via AT commands for added security
- Compact & Lightweight — measures just 96 × 68 × 19 mm and weighs approximately 117 g, ideal for panel mounting or enclosure integration
- Wireless Range — reliable communication up to 6–10 meters depending on environment
Technical Specifications
| Model | BT21A08 |
| Working Voltage | DC 12V |
| Standby Current (all relays off) | 15 mA |
| Current per relay "ON" | ~28 mA per additional relay channel |
| Max current (all 8 relays ON) | 229 mA |
| Communication Mode | Bluetooth 2.1 |
| Communication Distance | 6–10 meters |
| Control Voltage | AC 85–265V / 10A; DC 1–110V / 10A |
| Default Bluetooth Password | 1234 |
| Dimensions | 96 × 68 × 19 mm |
| Weight | ~117 g |
What's in the Box
- 1× BT21A08 8-Channel Bluetooth Relay Module
Important Notes
- Due to monitor and lighting differences, the actual item color may vary slightly from product images.
- Please allow a tolerance of 1–3 cm due to manual measurement.
- This module operates at low voltage (DC 12V input); however, relay output terminals may carry high-voltage loads — always follow proper electrical safety practices during installation.
For general electrical safety guidelines, visit the U.S. Consumer Product Safety Commission — Electrical Safety.
Frequently Asked Questions
Q: Is the BT21A08 Bluetooth relay module compatible with iOS devices?
A: The BT21A08 uses Bluetooth 2.1 (Classic Bluetooth) and is primarily designed for Android smartphones. Most iOS devices require Bluetooth Low Energy (BLE) for third-party app connectivity, so iOS compatibility is limited. For best results, use an Android device with the provided app.
Q: Can I control the 8-channel relay module with my own custom Android app?
A: Yes! The module accepts simple serial commands over Bluetooth, so you can integrate it into your own custom Android application. The provided app is a great starting point, but developers can send their own command strings to control each relay channel independently.
Q: What types of devices can I control with this relay module?
A: This module is ideal for controlling LED lighting strips, standard light fixtures, small appliances, fans, and other loads within its rated capacity (AC 85–265V / 10A or DC 1–110V / 10A per channel). It's a popular choice for DIY smart home automation projects.
Q: How do I change the Bluetooth device name or password?
A: You can modify the Bluetooth name and connection password using AT commands sent through a serial terminal or your app's serial interface. Detailed instructions are included in the Bluetooth Parameter Modification guide that accompanies the module.