jNode: A Sensor Network Platform that SupportsDistributed Inertial Kinematic MonitoringP.M.Scholl, D.Gordon, M.Scholz, M.Berning, K.Laerhoven

14. Juni 2012 | ESS, TU Darmstadt, PCS, Karlsruhe IT | P. M. Scholl, D. Gordon, M. Scholz, M. Berning, K. Laerhoven

Motivation

I a Wireless Sensor Network Platform that:I has a large array of sensors onboardI supports reliable and quick experimentationI supports standardized wireless and wired interfacesI is small, power-efficient and extendible

I Example Applications:I embedded motion trackingI ambulatory monitoringI human (group) activity recognition

I Plug’n’Play solution for wireless kinematic monitoring needs

14. Juni 2012 | ESS, TU Darmstadt, PCS, Karlsruhe IT | P. M. Scholl, D. Gordon, M. Scholz, M. Berning, K. Laerhoven

Sensorsgeared towards kinematic sensing

I attitude and heading / 3d orientation:I accelerometerI gyroscopeI compass/magnetic heading

I relative/absolute height:I barometric pressure

I relative distance/reflective proximityI infrared pulsed distanceI received signal strengthI ambient light

I ball-switchI temperatureI 3x IR LED for optical estimation

14. Juni 2012 | ESS, TU Darmstadt, PCS, Karlsruhe IT | P. M. Scholl, D. Gordon, M. Scholz, M. Berning, K. Laerhoven

Processingtwo micro-controllers for maximum flexibility

NXP/Jennic JN5148:

I Ieee802.15.4 compliant radioI 32-bit OpenRisc ArchitectureI 96kB RAM @16MHzI runs Contiki OSI fully re-programmable via USB

Atmel ATMega32u4:I includes USB subsystemI 8-bit Risc ArchitectureI 2.5kB RAM @16MHzI runs LUFA (optionally Arduino)I fully re-programmable via USB

provides TCP/IP v6/4 communication via 6LoWPANprovides standard-compliant USB devices

14. Juni 2012 | ESS, TU Darmstadt, PCS, Karlsruhe IT | P. M. Scholl, D. Gordon, M. Scholz, M. Berning, K. Laerhoven

Hardware Architecture

OTAP

webserver

timesync

6lowpan tcp/ipv6

fat32

µSDcard

serial

rndis/cdc ethernet

mass storage

Contiki

JN5148

LUFA (usb)

ATmega32u4

thermometer

barometer

gyroscope

accelerometercompass

ir distance

ambient lightball switch

li-ion battery

14. Juni 2012 | ESS, TU Darmstadt, PCS, Karlsruhe IT | P. M. Scholl, D. Gordon, M. Scholz, M. Berning, K. Laerhoven

Radio and Storagefrom a data collection point of view during experimentation

Radio - Ieee802.15.4:I 6LoWPAN for transmitting IPv6 via Contiki (or IPv4)I RPL/ROLL for building multihop routing tablesI UDP for unreliable transport, TCP for reliable transportI time synchronizationI but only reliable to the point of your control of the environmentI and constrained bandwidth (up to 500Kbps)

Storage - µSD-cardI fast and reliableI fat32 filesystem (most ubiquitous on usb sticks)I supported through the Contiki filesystem API (and via USB mass-storage)

14. Juni 2012 | ESS, TU Darmstadt, PCS, Karlsruhe IT | P. M. Scholl, D. Gordon, M. Scholz, M. Berning, K. Laerhoven

Energy Consumption

component current

◦C MPL115 0.6mAkPa 0.7mAlx VCNL4000 1.3mA

cm(ir ) 1.0mAm/s2 LSM303 0.6mAgauss 0.5mA◦/s L3G4200D 6.2mArssi JN5148 17.5mA

CPU JN5148 5.5mAATmega32 10mA

RF tx/rx JN5148 16.3mAµSD - ~3.4mA

total RF+µSD 36.05mAtotal RF 32.65mAtotal µSD 20mA

I worst-case power consumption:I no radio duty-cyclingI no sleeping on µCoreI fastest sampling rates

36.05mA

I run-time example, 400mAh battery:

~11hI still a lot to gain

14. Juni 2012 | ESS, TU Darmstadt, PCS, Karlsruhe IT | P. M. Scholl, D. Gordon, M. Scholz, M. Berning, K. Laerhoven

Example ApplicationsHuman Activity Recognition and Embedded Motion Tracking

14. Juni 2012 | ESS, TU Darmstadt, PCS, Karlsruhe IT | P. M. Scholl, D. Gordon, M. Scholz, M. Berning, K. Laerhoven

Conclusion

I a wireless sensor network platformI with a large array of sensors (kinematic and remote estimation)I quick and robust experimentation and standard-complianceI open-source in software and hardware

https://github.com/teco-kit/Jennisense

Thanks for your attention

14. Juni 2012 | ESS, TU Darmstadt, PCS, Karlsruhe IT | P. M. Scholl, D. Gordon, M. Scholz, M. Berning, K. Laerhoven