Accelerating IoT Designs with Bluetooth Low Energy Modules

For developers of IoT devices, Bluetooth Low Energy (BLE, also known as Bluetooth Smart) has many advantages. As the name suggests, low power consumption is inherent, and a complete low-power Bluetooth module can basically provide plug-and-play wireless connectivity. Maximizing the benefits of a Bluetooth Low Energy module is to take advantage of the advantages of Bluetooth Low Energy.

By now, most developers have at least heard of Bluetooth. This is a wireless protocol that originally appeared in wireless audio streaming applications. The low-power Bluetooth version is shipped with Bluetooth v4.0 and adapts to low-power applications by reducing the transmit power and data speed compared to the core specification (the latest version of Bluetooth is v4.2). Unlike the full core specification, Bluetooth Low Energy has a range limit of 50 meters and a speed limit of 0.27Mbps.

Developers new to the Bluetooth Low Energy standard should consider these performance degradations as key points when setting system expectations. Just because the Bluetooth Low Energy protocol is used in a design doesn't mean low power consumption. Designed operational coverage and data speeds play an important role in establishing energy consumption requirements, as does the system's overall communications strategy. Developers need to carefully consider these factors to achieve guaranteed low power consumption.

There are many other factors to consider when designing Bluetooth Low Energy IoT devices. The user interface (UI) designed may be related to the same built-in buttons and displays as traditional embedded systems. Or the design can provide the user interface using an app running on a smartphone. Likewise, devices can utilize mobile phones or fixed gateway devices for Internet connectivity.

Developers can also choose to pair a Bluetooth low energy device with a host device to establish two-way communication, or work in advertising mode to enable unverified one-way transmission of small amounts of data (approximately 30 bytes). Bluetooth low energy devices (such as sensors) operating in advertising mode can periodically send data to listening devices without consuming energy to establish and maintain a complete two-way link. However, the use of advertising intervals and advertising modes (such as scan requests, which allow listening devices to request additional data from a Bluetooth Low Energy device) can significantly impact the energy consumption values of a Bluetooth Low Energy design.