Illustrative project: Bluetooth Smart Leica Disto
On building sites folding rulers have long given way to laser distance sensors. Now, thanks to a new device developed by Leica Geosystems AG, measured distances can be wirelessly transmitted to an iPhone or iPad and can then be incorporated into a photograph or drawing. The ZHAW School of Engineering’s Centre of Signal Processing and Communications Engineering (ZSN) played a key part in developing the technology used in this Bluetooth Smart solution.
Smartphones and tablets have become everyday working tools for many architects, planners and craftsmen – and that applies to building sites as much as any other place of work. For that reason, Leica Geosystems AG began incorporating a conventional Bluetooth interface into its DISTO laser distance sensor several years ago. This solution does, however, have a number of disadvantages, since it is relatively expensive, uses considerable amounts of power and takes some time to establish a connection.
A further disadvantage is that a special licence from Apple is needed to transmit the measurement data to an iPhone or iPad. In early 2012, Leica presented this problem to the Centre of Signal Processing and Communications Engineering (ZSN). It chose the ZSN as its university partner for this endeavour, because wireless communication is a field in which the Centre both teaches and carries out applied research and development work.
“Bluetooth Smart supports cost-effective communications solutions with low power consumption, modest memory and calculation requirements, efficient discovery and connection procedures and simple protocols and services.”
Professor Marcel Rupf, Director, Centre of Signal Processing and Communications Engineering
Since 2011, many tablets and smartphones now also have a Bluetooth Smart interface in addition to their conventional Bluetooth capability. Bluetooth Smart is designed for sensor-based wireless data transmission. “Bluetooth Smart supports cost-effective communications solutions with low power consumption, modest memory and calculation requirements, efficient discovery and connection procedures and simple protocols and services,” explains Marcel Rupf, the ZSN’s Director. “Bluetooth Smart is also supported by the iOS operating system.” As its first step in this one-year CTI project, the ZSN specified the Bluetooth Smart communications procedure between the distance sensor and the smartphone. “When we started the project we had no distance sensor with a wireless interface available to us, so we evaluated a Bluetooth Smart protocol using our own electronic solution with a wireless chip and a microprocessor,” explains Patrick Rennhard, who managed the project for the ZSN. It was this solution that Leica then incorporated into its DISTO distance sensor.
“During the software development phase, it was not always easy to reconcile the various proposed user features.”
Patrick Rennhardt, Research Associate, Centre of Signal Processing and Communications Engineering
In the second phase of the project, the ZSN developed an extended basic app in iOS. “During the software development phase, it was not always easy to reconcile the various proposed user features,” explains Patrick Rennhard. “The final result was however successful.” DISTO users can now use their tablet or smartphone to produce a photo or sketch of the object they are measuring, wirelessly upload the measurements they have made with the distance sensor and then drag and drop the figures onto their photo or sketch. The photos or sketches with their integrated measurement data can simply be sent by e-mail or MMS from the building site to the office, thus saving time and money.
By late February 2013, Leica had already launched its DISTO D510 with the new Bluetooth Smart interface. A matching iOS DISTO-Sketch app is available from the App Store and is meeting with enthusiastic customer approval.
At a glance
Participating institutes and centres:
Financing: financial support by Leica Geosystems AG
Project status: completed