An increasing number of sensors communicate wirelessly to for example a training clock, a smartphone or a computer. Often it is desired that the sensor unit takes up little space, has a low cost per unit and works without external power supply with a long life without battery change. A sensor unit can also be part of a larger network of sensors that wirelessly send information from several measurement sites to a collecting gateway. Collected data is sent via mobile networks or the Internet to a cloud platform that processes, stores and visualizes the information.
At RISE, we have experience in designing and building wireless sensor systems based on the needs of the customer. We can help with the entire chain from idea to a pilot system through:
Active wireless sensors have internal batteries to supply energy sensors, readout electronics and radio unit. Active sensors can measure and transmit data continuously, but to save energy it is more common for the sensors to measure at a given time interval and to sleep between measurements. Measured data is sent to a recipient that saves data locally or sends data on via mobile networks/internet to a cloud database. Depending on the requirements of the application, the battery life of a wireless sensor unit can vary from days up to several years.
There are many standards for wireless sensor communication and the technology is rapidly evolving. Usually, small amounts of data need to be transferred after each measurement. Examples of standards for wireless sensor communication that RISE have experience working with are Bluetooth Low Energy (BLE), ANT Wireless, LoRaWAN and NB-IoT.
Passive sensors have no internal energy source to perform the measurements and data transmission. Passive sensors are usually simpler, cheaper and take up less space than active sensors. The passive sensor is supplied with energy from an external reader, which means that the sensors cannot log data and only measure while reading.
Below are a few examples of passive wireless sensors that RISE has experience working with: