More Project Examples and Tools
Battery-less Presenter (Piezo As Harvester)
This presenter developed by Algra, Microdul and ZHAW allows the user to control a presentation. The keys generate enough energy to send a wireless message to move one slide forward or backward. No need for batteries. Different wireless frames can be used (proprietary 2.4 GHz, BLE ADV frame, Sub-GHz …). The important issue is that they fit the energy budget.
Battery-less Joystick (Harvest from Temperature Differences)
Using the Seebeck effect, energy is converted from heat to electrical energy (here temperature differences between the surrounding and your body). That energy powers a demanding system that detects the movements of the arm and sends measurements wirelessly to a PC for the control of a game. Reaction and reliability in the communication are vital for the game to be played properly.
Security and Usability
It is important in some applications to secure the wireless communication and prevent unauthorized parties from having access to the information or tampering with the information. To accomplish this, more energy and processing is required, further complicating the energy optimization. We strive to research and develop low-energy and low-cost methods that enable the implementation of security in wireless nodes. Additionally, we also recognize the need of simplifying the interface between nodes and user.
For example, on a very small energy budget, we have implement:
- AES-128 encoded frames, with or without rolling code. The NV memory requires less than a couple of microjoules for updates. Millions of cycles are possible.
- 2-way communication systems to insure that the data has arrived.
- A challenge response wireless system that requires less than 25 microjoules, as documented in the energy profile below.
Example of a sensor node: nRF52 used as microcontroller and for communication (Bluetooth Smart), various sensors, NFC for near field bidirectional communication, optical interface for easy unidirectional communication (e.g. pattern coded as flickering of a smartphone display).
Appropriate tools are necessary in order to efficiently carry out our research and development tasks. When possible, we acquire tools that are on the market. In cases where nothing appropriate exists on the market, we develop our own tools.
BLE sniffer from Ellisys (used for multi-channel sniffing of Bluetooth Smart)
The Ellisys Bluetooth Explorer sniffer supports one-click concurrent and tightly synchronized capture of protocols like Classic Bluetooth, Bluetooth Low Energy and Wi-Fi as well as other protocols.
ZHAW multi-channel sniffer (In development)
A sniffer with 10 heads, capable of sniffing Bluetooth smart frames, 802.15.4 frames or other proprietary frames in the 2.4 GHz band. More heads can be added, more sniffers combined to cover all channels. The heads can also be used to add diversity features, act as “pattern generators”. A key aspect while using several sniffers is the synchronisation.
This device is built by us to meet the evolving demands of research and development. Some of the features are:
- Parallel and simultaneous monitoring of all Bluetooth Smart channels
- Parallel and simultaneous monitoring of all 802.15.4 channels (2.4 GHz)
- Synchronization of all connected sniffers at different locations (better than a microsecond), which is crucial in debugging mesh systems that cover a large surface. Synchronization is achieved in different ways.
- Results visualized using Wireshark (you can adapt the visualization)