Wireless Data Acquisition
Real-time data acquisition is commonly required in a diversity of areas such as power grid, healthcare, industrial production, water conservancy, meteorology and agriculture. In practice, there must be numbers of acquisition spots scattered throughout large areas that are mostly enduring harsh environment. The use of phone lines or cables in these areas for data transfer would get half the result with twice the effort. While wireless networks could cover all the data acquisition points with much lower cost and less effort for installation and maintenance than wired networks.
A complete wireless data acquisition system is basically made up of sensors, analog front-end, a MCU, wireless transceivers, and a remote host. The sensors collect analog information in the natural world and convert it into electronic signals. Then the analog front-end implements sampling, amplifying, filtering and A/D conversion on the output signals from those sensors. The MCU is responsible for processing the digital signals from the front-end and transferring to the wireless transceivers, as well as controlling other function units of the system. The wireless transceiver transmits the acquired data to the remote host and also receives instructions from the host. Currently most transceivers work on ISM band, but other bands used for ZigBee, Wi-Fi, and GPRS/GSM/CDMA can also be found in some wireless data acquisition systems. The selection of wireless bands in practice should be determined by the required data transfer rate, distance and power consumption.
As the wireless communication and RF technologies keep evolving, wireless data acquisition systems present remarkable advantages in terms of easy and fast installation with low cost, and are gradually taking the place of the traditional wired systems.