Libelium designed a new Bluetooth wireless module for its Waspmote wireless sensor network platform. Bluetooth wireless module enables wireless sensor networks to be directly linked to portable devices such as smart phones, PDA mobile phones, tablet PC, and laptop computers. This capability is particularly useful for medical applications and for industrial diagnostics. Additionally, when combined with its Meshlium multi-protocol wireless sensor network router, it supports the deployment of hybrid ZigBee- and Bluetooth-based wireless sensor networks.

Bluetooth Wireless Sensor Network SystemThe new Bluetooth module extends the Waspmote wireless sensor network platform by offering a new choice for radio communication. The platform is extremely modular allowing the use of a wide range of modules for both wireless communication and sensors. Now wireless sensor network users can choose between a Bluetooth module and a range of ZigBee modules covering the main frequency bands (2.4GHz, 868MHz, 900MHz).

Libelium CTO David Gascón says, “This module will be particularly useful for medical applications requiring the integration of biometric sensors and for sending sensor information to Bluetooth-equipped industrial systems”. He adds, “Users with existing Bluetooth-based infrastructure will be able to extend it to include Waspmote and its range of sensors”.

The new Bluetooth module is able to send sensor data frames to smart phones that support Serial Port Profile (SPP). Security mode is implemented with PIN validation which can be preconfigured such as a “Network Key” and it allows the management of a Trusted Nodes list in order to create secured networks.

With both Bluetooth and ZigBee using the 2.4GHz industrial, scientific and medical (ISM) radio band there is the possibility of interference. For this reason Waspmote enables Bluetooth and ZigBee communication to work in the same environment by using Adaptive Frequency Hopping (AFH) which enables the Bluetooth radio to dynamically identify channels already in use and to avoid them. In the figure below we can see how AFH avoids transmitting in frequency bands which are being used by DSSS technologies such as ZigBee and Wifi networks, allowing a complete coexistence between all them.