When you come across a Bluetooth module, whether you are a product manager, an engineer or an enthusiast, you can evaluate whether it is suitable for your project from the following core dimensions. This is like choosing a "wireless communication partner" for your device, which requires a comprehensive investigation.
You can categorize these parameters into three major types:
1. Basic performance category (which determines what it can do),
2. Hardware interface class (which determines how to connect it),
3. Development and production class (which determines how troublesome it is to use it).
I. Basic Performance Parameters (Determining Module Capability)
These are the "resumes" of the modules, which directly determine their communication capabilities.
1,Bluetooth version
What is it: such as 4.2, 5.0, 5.1, 5.2, 5.3, 5.4.
Why it matters: New versions usually mean lower power consumption, faster speed, longer distance and more features.
How to choose
BLE 5.0/5.1: Currently the mainstream choice for Internet of Things devices, with high cost performance.
BLE 5.2/5.3: Applications with higher requirements for connection stability, latency and security.
Bluetooth 5.4: The latest features, such as periodic broadcasting with response function, suitable for electronic price tags, item tracking, etc.
Dual-mode version: If it is necessary to support both traditional Bluetooth (such as audio transmission) and low-power Bluetooth simultaneously, a dual-mode module should be selected.
2,Protocols and Models
What is it: Low-power Bluetooth, Classic Bluetooth or dual-mode Bluetooth.
Why important: This determines the "working nature" of the module.
How to choose
Low-power Bluetooth: The choice of the vast majority of IoT devices, such as sensors and wearable devices, is characterized by extremely low power consumption.
Classic Bluetooth: Mainly used for audio streaming (speakers, headphones) and high-speed data transmission.
Dual-mode Bluetooth: It has comprehensive functions, but its cost and power consumption are relatively high.
3,Transmission distance
What is it: Usually measured in meters, such as 50 meters, 100 meters, 200 meters.
Why important: It determines the effective communication range between devices.
Note: This distance is usually the data in an ideal open environment. In actual use, obstacles such as walls and human bodies can significantly shorten the distance. Pay attention to its transmission power and receiving sensitivity. The higher these two values are, the greater the theoretical distance.,
4,Transmission rate
What is it: The unit is kbps or Mbps.
Why important: It determines how much data can be transmitted per second.
How to choose
Transmitting sensor data (such as temperature and humidity) : A few kbps is sufficient.
Transmitting audio streams: Requires several hundred kbps or more.
Transfer files or high-quality audio: Mbps level is required.
5,Power consumption
What is it: Usually, the current values under different working modes are given, such as sleep current (~1.5uA), broadcast current (~20uA), and continuous transmission current (~10mA).
Why important: For battery-powered devices (such as wristbands and remote controls), this is a decisive parameter that directly affects battery life.
How to view it: Focus on peak current and sleep current.
Ii. Hardware and Interface Parameters (Determining How to Integrate)
These parameters tell you how to "install" this module into your product.
1,Interface type
What is it: The physical way in which a module communicates with the main control chip (such as an MCU).
Why it matters: It determines the difficulty of your hardware design and the way you communicate.
Common types
UART: The most commonly used, simple and easy to use, it realizes "serial port transparent transmission", and developers do not need to have a deep understanding of the Bluetooth protocol stack.
USB: It is often used in Bluetooth adapters or devices that require high-speed data transfer.
SPI/I2C: It is relatively fast and is used for communication with sensors or other chips.
I2S: Specifically designed for transmitting audio data.
2,Antenna type
What is it: The "ears" for signal transmission and reception.
Why important: It affects signal strength, distance and product appearance.
Common types
PCB on-board antenna: Low cost, small size, but short distance.
Ceramic antennas: Small in size and superior in performance to on-board antennas.
External IPEX interface antenna: It has the best performance, the longest distance, and the antenna position can be flexibly arranged through wires. It is the first choice for high-end products.
3,Working voltage and IO port level
What is it: such as 3.3V, 1.8V to 3.6V.
Why important: It must match the voltage of your main control MCU; otherwise, a level conversion circuit is required, increasing complexity and cost.
4,Size and Packaging
What is it: The physical size of the module and the pin soldering method.
Why it matters: It determines how much space it takes up on your PCB board and the production process.
Common types: Surface mount type (SMD, the most mainstream), stamp hole type (for more secure soldering), pin type (often used in development boards).
Iii. Development, Certification and Production Parameters (Determining Usability and Compliance)
These parameters are related to the difficulty, cycle of your product development and whether it can be legally sold.
1,Software development support
What is it: Software resources provided by suppliers.
Why important: It directly determines the development efficiency and difficulty.
Attention to
SDK: Software Development Kit. Is it complete and easy to understand?
AT instruction set: If AT instructions are used, is it clear and straightforward?
Technical support: Can the supplier provide timely technical support?
2,Certification
What is it: Official or industry mandatory certification.
Why important: It is the "pass" for the product to be launched and sold on the market.
Core Certification
BQB Certification: A mandatory certification by the Bluetooth Special Interest Group, it is the cornerstone for ensuring Bluetooth compatibility. Using modules that have passed the BQB certification, your terminal product certification will be much simpler.
Radio type approval certification: such as FCC in the United States, CE in the European Union, and SRRC in China. If the module has passed these certifications, it can greatly simplify the market entry process of your product.
3,Operating temperature range
What is it: such as -40℃ to +85℃.
Why important: If your product needs to be used in harsh environments such as industry, vehicles or outdoors, you must pay attention to this parameter. Consumer-grade products typically operate at temperatures ranging from -20℃ to +70℃.
