0000000000644720
AUTHOR
Natale Galioto
DEMO: Unconventional WiFi-ZigBee communications without gateways
Nowadays, the overcrowding of ISM bands is becoming an evident limitation for the performance and widespread usage of 802.11 and 802.15.4 technologies. In this demo, we prove that it is possible to opportunistically exploit the inter-technology interference between 802.11 and 802.15.4 to build an unconventional low-rate communication channel and signalling protocol, devised to improve the performance of each contending technology. Differently from previous solutions, inter-technology communications do not require the deployment of a gateway with two network interfaces, but can be activated (when needed) directly between two heterogeneous nodes, e.g. a WiFi node and a ZigBee node. This capab…
Design and realization of a portable multichannel continuous wave fNIRS
A design and implementation of a portable functional Near InfraRed Spectroscopy embedded system prototype is described. In this theoretical and experimental work, we present an embedded system hosting 64 LED sources and 128 Silicon PhotoMultiplier detectors (SiPM). The elementary part of the structure is a flexible probe “leaf” consisting of 16 SiPMs, 4 couples of LEDs, each operating at two wavelengths, and a temperature sensor. The hardware system is based on an ARM main microcontroller that allows to perform both the switching time of LEDs and the acquisition of the SiPM outputs. The performed preliminary experimental tests achieved very promising results, thus demonstrating the effectiv…
Design and development of a fNIRS system prototype based on SiPM detectors
Functional Near Infrared Spectroscopy (fNIRS) uses near infrared sources and detectors to measure changes in absorption due to neurovascular dynamics in response to brain activation. The use of Silicon Photomultipliers (SiPMs) in a fNIRS system has been estimated potentially able to increase the spatial resolution. Dedicated SiPM sensors have been designed and fabricated by using an optimized process. Electrical and optical characterizations are presented. The design and implementation of a portable fNIRS embedded system, hosting up to 64 IR-LED sources and 128 SiPM sensors, has been carried out. The system has been based on a scalable architecture whose elementary leaf is a flexible board …
Design and implementation of a portable fNIRS embedded system
We report on the design, development and operation of a portable, low cost, battery-operated, multi-channel, functional Near Infrared Spectroscopy embedded system, hosting up to 64 optical sources and 128 Silicon PhotoMultiplier optical detectors. The system is realized as a scalable architecture, whose elementary leaf consists of a probe board provided with 16 SiPMs, 4 couples of bi-color LED, and a temperature sensor, built on a flexible stand. The hardware structure is very versatile because it is possible to handle both the switching time of the LED and the acquisition of the photodetectors, via an ARM based microcontroller.
Low cost electrical current sensors with automatic measurement range
We present a simple and low cost Smart Current Sensor with wide automatic measurement range. The logic core system of the sensor is the Atmel AT32UC3C2256C AVR 32-bit microcontroller, the wireless core is a Microchip MRF24J40MA IEEE 802.15.4 RF transceiver[3]. The MCU features 11 ADC multiplexed channels, with 12-bit resolution and sample rate up to 2Msps, two of which can be sampled in parallel. The sensing board consists of two hall-effect based current sensors, assembled on different PCBs in order to perform with different sensitivities. Custom primary conductor design allowed us to sense the current flowing in the conductor with two different sensitivities: the sensor mounted inside the…
Low Cost Electrical Current Sensors with Extremely Wide Measurement Range
A new electrical current measurement system is presented. It features the ability to dynamically and automatically change its measurement range to the sensed current amplitude without user action. It also exhibits galvanic isolation and near zero insertion loss characteristics.
Smart plugs: A low cost solution for programmable control of domestic loads
International audience; Balancing energy demand and production is becoming a more and more challenging task for energy utilities. This is due to a number of different reasons among which the larger penetration of renewable energies which are more difficult to predict and the meagre availability of financial resources to upgrade the existing power grid. While the traditional solution is to dynamically adapt energy production to follow the time-varying demand, a new trend is to drive the demand itself by means of Direct Load Control (DLC). In this paper we consider a scenario where DLC functionalities are deployed at a large set of small deferrable energy loads, like appliances of residential…
Cross-Technology WiFi/ZigBee Communications: Dealing With Channel Insertions and Deletions
In this letter, we show how cross-technology interference can be exploited to set up a low-rate bidirectional communication channel between heterogeneous WiFi and ZigBee networks. Because of the environment noise and receivers' implementation, the cross-technology channel can be severely affected by insertions and deletions of symbols, whose effects need to be taken into account by the coding scheme and communication protocol.
BusyBee: Low Rate WiFi-ZigBee Communications without Gateways
Nowadays, the overcrowding of ISM bands is becoming an evident limitation for the performance and widespread us- age of 802.11 and 802.15.4 technologies. In this demo, we prove that it is possible to opportunistically exploit the inter- technology interference between 802.11 and 802.15.4 to build an unconventional low-rate communication channel and sig- nalling protocol, devised to improve the performance of each contending technology. Differently from previous solutions, inter-technology communications do not require the deploy- ment of a gateway with two network interfaces, but can be activated (when needed) directly between two heterogeneous nodes, e.g. a WiFi node and a ZigBee node. Thi…
A Novel Wireless Sensor Network for Electric Power Metering
Wireless sensor network with lightweight and efficient communication infrastructures are today a great interest, both at research and industrial level, as they are the basis for reliable monitoring services. Mesh networks are ideal candidates in this scenario, as they can be very fault-tolerant. After introducing wireless network systems requirements, we show the design of a mesh network routing protocol based on AODV schemas. Its implementation runs on top of low-cost off-the-shelf components, and allowed us to build a custom power meter wireless sensor node.
Supporting Autonomous Navigation of Visually Impaired People for Experiencing Cultural Heritage
In this chapter, we present a system for indoor and outdoor localization and navigation to allow the low vision users in experiencing cultural heritage in autonomy. The system is based on the joint utilization of dead-reckoning and computer vision techniques on a smartphone-centric tracking system. The system is explicitly designed for visually impaired people, but it can be easily generalized to other users, and it is built under the assumption that special reference signals, such as colored tapes, painted lines, or tactile paving, are deployed in the environment for guiding visually impaired users along pre-defined paths. Differently from previous works on localization, which are focused …
Pathological voice analysis via digital signal processing
The interest in pathological voice analysis for specific neurological diseases is growing up aiming to offer more Health-care tele monitoring services since new high performing electronic devices are available for the end-user. In this article we show some parameters that can be digitally extracted and analyzed from pathological voices, in order to find a distinctive sign of the Parkinson disease. As a result, we will show a parameter that gives some information about the Parkinson disease characterization, particularly for male patients. We will also discuss about the needed computational cost related to parameters extraction and elaboration, aiming to target a possible tough yet portable …
Smart Plugs for smarter cities
Load control in modern power grids is becoming more and more important. Recently, energy monitoring and load control has gained interest from several actors such as energy utilities, and Demand Response mechanisms allow consumers to respond to signals from energy suppliers in order to reduce their energy consumption during critical periods, in exchange of discounts on electricity bills. Direct Load Control mechanisms allow energy suppliers, through the adoption of Smart Plugs, to automate load switch-o during such periods. These mechanisms have been traditionally applied to industrial customers only, leaving a major part of loads in the grid, e.g. household appliances, uncontrolled. Commerc…
A Novel Wireless Sensor Network for Electric Power Metering
Wireless sensor network with lightweight and efficient communication infrastructures are today a great interest, both at research and industrial level, as they are the basis for reliable monitoring services. Mesh networks are ideal candidates in this scenario, as they can be very fault-tolerant. After introducing wireless network systems requirements, we show the design of a mesh network routing protocol based on AODV schemas. Its implementation runs on top of low-cost off-the-shelf components, and allowed us to build a custom power meter wireless sensor node.