As a professional semiconductor Bluetooth module development company, we understand that selecting the right Bluetooth module for an IoT project is a critical step toward product success. An unsuitable module can lead to development delays, cost overruns, and even product failure. This guide will systematically walk you through the selection process.
Step 1: Define Your Core Requirements
1. Analyze the Application Scenario
Data Rate Requirements:
Low-speed sensors (temperature, humidity, switch status): A few kbps; BLE is perfectly sufficient.
Audio transmission: Requires ≥1 Mbps; choose Bluetooth Classic or BLE Audio (LC3).
Firmware Upgrade (OTA): Consider a medium data rate to reduce upgrade time.
Transmission Distance:
Personal Area (1-10 meters): Standard BLE modules.
Full Indoor Coverage (10-50 meters): Choose high-power modules or modules supporting long-range features (Bluetooth 5.0+).
Outdoor/Industrial Environments (>100 meters): Require specifically optimized long-range modules with external antennas.
Number of Nodes:
One-to-One Connection: Standard point-to-point modules.
Star Network (one central device to multiple peripherals): Ensure the module supports multiple connections.
Large-scale Network (e.g., lighting, sensor networks): Consider Bluetooth Mesh or future Bluetooth 5.4 features like PAwR.
2. Power Consumption Constraints
Power Supply Method is Decisive:
Battery-powered (Button Cell): Average current must be <10 µA; choose BLE modules with deep sleep current <1 µA.
Rechargeable Battery: Can accept average current in the mA range.
Wired Power Supply: Fewer power restrictions; priority can be given to performance and cost.
Step 2: Compare Technical Specifications
Bluetooth Version & Feature Matrix
| Bluetooth Version | Key Features | Suitable Scenarios |
|---|---|---|
| Bluetooth 4.2 | Basic BLE, IP Support | Simple sensors, cost-sensitive projects |
| Bluetooth 5.0 | 2x Speed, 4x Range, 8x Broadcasting Capacity | The "sweet spot" for most IoT applications |
| Bluetooth 5.1 | Direction Finding (AoA/AoD) | Indoor positioning, asset tracking |
| Bluetooth 5.2 | LE Audio (LC3 Codec), Enhanced ATT | Audio products, multi-device synchronization |
| Bluetooth 5.3/5.4 | Periodic Advertising, Faster Connection Response | Large-scale sensor networks, real-time control |
Core Parameter Checklist
RF Power Output: +20 dBm offers longer range but higher consumption; 0 dBm balances power and distance.
Receiver Sensitivity: ≤-97 dBm is good, ≤-102 dBm is excellent (longer range).
Interface Options:
UART (AT Commands): Simplest integration, suitable for projects with limited MCU capability.
SPI/I2C: Higher data rates.
USB: Suitable for PC peripherals.
GPIO: For controlling external devices.
Antenna Options:
PCB Antenna: Lowest cost, but limited range and directionality.
Ceramic Antenna: Preferred for miniaturized devices.
IPEX External Antenna: Best performance, flexible placement.
Memory Resources:
8-64 KB RAM: Basic applications.
128 KB+ RAM: Complex applications, OTA upgrade buffer.
Step 3: Consider Ecosystem & Development
1. Evaluate Development Support
SDK Maturity: Are there rich examples and clear documentation?
Development Toolchain: Does it support mainstream IDEs (Keil, IAR, Eclipse)?
Protocol Stack Flexibility: Is it a closed AT command set or open for secondary development?
Community & Forums: Is there an active user community for support?
2. Production & Procurement Factors
Certification Status:
BQB (Mandatory): Prerequisite for any Bluetooth product launch.
FCC/CE/RoHS: Target market access requirements.
Industry-specific Certifications: e.g., Medical (FDA), Automotive (AEC-Q100).
Supply Stability:
Does the module's lifecycle match your product cycle (typically 3-5 years)?
Are there second-source or pin-to-pin compatible options?
Cost Structure:
Look beyond unit price; also consider:
Development Cost: Learning curve, development time.
BOM Cost: Need for external Flash, crystals, etc.
Certification Cost: Pre-certified modules can save tens of thousands of dollars.
Step 4: Recommendations for Common IoT Scenarios
Scenario 1: Smart Home Sensors (Door/Window, Temp/Humidity)
Recommended Choice: Bluetooth 5.0/5.1 BLE Module
Key Features:
Ultra-low power (average current <5 µA)
Support for advertising (data reporting without pairing)
Small form factor (e.g., 10×10 mm)
Integrated temperature and voltage sensors
Example: Our BMS100 Series, with 0.8 µA deep sleep current, pre-certified FCC/CE/BQB.
Scenario 2: Wearable Devices/Health Monitoring
Recommended Choice: Bluetooth 5.2/5.3 BLE Module
Key Features:
Balanced power and performance.
Support for secure encryption (protects health data).
Stable connection performance (resistant to motion interference).
Optional audio support.
Example: Our WDR200 Series, optimized for wearables, passes medical-grade EMC tests.
Scenario 3: Industrial IoT Gateway
Recommended Choice: Bluetooth 5.0+ Dual-mode (BLE + Classic) or Bluetooth Mesh Module
Key Features:
High receiver sensitivity (≤-102 dBm)
Support for multiple connections (at least 20 slave devices)
Industrial temperature range (-40°C to +85°C)
Optional industrial interfaces (RS485, Ethernet)
Example: Our IGW500 Series, supports 50+ simultaneous connections, operating temp -40°C to +105°C.
Scenario 4: Audio Products (Wireless Speakers, Headsets)
Recommended Choice: Bluetooth 5.2+ Dual-mode Module with LE Audio support
Key Features:
Support for high-quality audio codecs (SBC, AAC, aptX, LC3)
Low audio latency (<50 ms)
Stable A2DP/HFP/HSP protocol stack
Example: Our ADU300 Series, integrates DSP, supports multi-point connection and LE Audio.
Step 5: Pitfall Avoidance Guide
Common Selection Mistakes
Over-engineering: Choosing a high-end audio module for a simple sensor, increasing cost 3-5x.
Ignoring Certifications: Choosing uncertified modules, preventing product launch or causing recalls.
Underestimating Power Consumption: Selecting a high-power module for a button cell device, resulting in weeks instead of years of battery life.
Overlooking Firmware Space: Not reserving enough Flash for future OTA upgrades.
Poor Antenna Design: Choosing a PCB antenna without sufficient keep-out area, halving the range.
Suggested Next Steps
After preliminary screening of a few candidate modules, we recommend:
Request a Development Kit: Test performance on actual hardware.
Conduct RF Testing: Validate real-world range within your product enclosure.
Verify Power Consumption: Measure current draw in real usage scenarios.
Small-Batch Trial Production: Verify supply chain and manufacturing process.
Pro Tip: As a Bluetooth module supplier, we offer complimentary Selection Consulting Services. If you can provide the following information, our engineers can give targeted recommendations within 24 hours:
Device power supply method and expected battery life.
Data transmission frequency and packet size.
Target retail price range.
Estimated annual production volume.
Mandatory certification requirements.
Choosing the right Bluetooth module is both a technical and a business decision. A well-considered choice will lay a solid foundation for your IoT product's success.
[Contact our technical team now for personalized selection advice →]
