Interacting w ith Smart Objects: Application Scenarios w ith the BTnode Platform Friedemann Mattern ETH Zurich Institute for Pervasive Computing ET ETH Eidgenössische Dagstuhl March 2004 Technische Hochschule Zürich
Friedemann Mattern Making Things Smart w ith Wireless Sensors � Smart-Its project (2001-2003) � part of the European „Disappearing Computer“ initiative � Goal: enable everyday objects as smart interconnected information artifacts � by attaching wireless sensors („Smart-Its“) to them � objects become self aware, context sensitive, cooperative � Integration into background computing environment F. Ma. 3
Friedemann Mattern The NCCR „Mobile Information and Communication Systems“ � N ational C enter of C ompetence in R esearch � First phase until 2005, planned total time: 10 years � Focus: decentralized, self-organizing mobile networks � Sub-project IP9 “Communicating Embedded Systems” � one out of 11 projects � Jan Beutel, Kay Römer, Roger Wattenhofer,… � BTnodes sensor node platform F. Ma. 4
Friedemann Mattern BTnode – An Experimental Hardw are Platform � CPU: 8 bit RISC, 8 MIPS � Generic sensor interfaces � Communication: Bluetooth � Lightweight event-driven OS � Unit cost @ 200 units: $110 F. Ma. 6
BTnode architecture Lightweight wireless communica Lightweight wireless communication and computing platform tion and computing platform based on a Bluetooth radio module and a mi based on a Bluetooth radio module and a microcontroller. crocontroller. Bluetooth has the advantage of Bluetooth has the advantage of – availability today for experimentation – compatibility to interface to consumer appliances – an abstract, standardized high level digital interface 8
BTnode – Some Hardware Details Memory Memory Integrated Communication Communication LEDs, 128 kB Flash, 244 kB PIFA antenna Bluetooth module Reset, Clocks SRAM, 4 kB EEPROM 40 mm 40 mm 61 m 61 mm CPU CPU Generic sensor UART and I2C Power Atmel ATmega 128L MCU interfaces data interfaces management 8-Bit RISC (max. 8 MHz ~8MIPS) 12 cm 3 , 2 mW (low power) – 150 mW 9
BTnode System Software Lightweight OS Lightweight OS –event-driven application model –cooperative multithreading –device drivers ( UART, RTC, ADC, ... ) –static memory allocation –minimum memory footprint Programming Programming –standard C language –high-level Bluetooth interface –system software available as library –emulation environment on Linux 10
Event driven OS/application integration Approach common to embedded systems Approach common to embedded systems Geared towards processing of external events Geared towards processing of external events – sensor values, data packets, state changes – only one handler active at a time One application per system at a time One application per system at a time – application resident in device – no dynamic process model – events triggered by OS/driver functions and applications No real-time OS know No real-time OS knowled ledge necessary e necessary for application design for application design 11
Rapid prototyping – Linux emulation Native compilation and execution on Linux Native compilation and execution on Linux – using adapted drivers to match the host system – with a serial Bluetooth device on a PC or iPAQ Bluetooth PC BTnode + use unlimited resources of host + deployment platform + bridging networks − slow upload necessary + comfortable application debugging ≈ 13
BTnode rev3 architecture Multiple radio frontend BTnode Multiple radio frontend BTnode – wake-up radio and low duty cycle power schemes Integrated modular extension port Integrated modular extension port Integrated power management Integrated power management – power supply (2x AA) or DC input – main power switch and reset – switchable supplies for subsystems – power consumption 0.5-50 mA @ 3.3V (projected) 14
Friedemann Mattern Attachable Sensor Module TeCO, University of Karlsruhe F. Ma. 17
Friedemann Mattern BTnode Backend Connectivity Internet � Easy access to background Long- range Bluetooth infrastructure via BT-gateway link gateway � GSM � SMS short text services � WLAN � Internet � ... � Easy to integrate with commodity devices Short-range � Simplifies development, links within WSN monitoring and debugging F. Ma. 18
Friedemann Mattern BTnode – Easy Integration w ith User Interface Devices PDA Camera Mobile phone BTnode PC peripherals BTnode F. Ma. 19
Friedemann Mattern Outsourcing of Computations as a System service � BTnodes have limited resources � Outsource computations on nearby more powerful devices � Mobile code is executed on remote device � PDA, mobile phone, laptop computer… F. Ma. 20
Friedemann Mattern An Early Application of BTnodes: Smart Products � Acceleration sensor � Temperature sensor � Standard Bluetooth profiles for SMS, object push and RFCOMM F. Ma. 21
Friedemann Mattern Smart Products Bluetooth SMS via GSM sensor event � The BTnodes act as “smart user control tags“ for valuable products � Alert via SMS of sensor events such as shock or heat � Interactive dialogue with the smart product F. Ma. 22
I nteracting with Smart Everyday Objects…
…Using Sensors (1)
Friedemann Mattern Interacting w ith Disappearing Computers? � Hold two artifacts (with attached Smart-Its) together – and shake! F. Ma. 25
Friedemann Mattern Interacting w ith Disappearing Computers? � Hold two artifacts (with attached Smart-Its) together – and shake! F. Ma. 26
Friedemann Mattern Shaking Tw o Objects Together Establishes a ”Friendship” � The shaking motion establishes a shared context (i.e., acceleration pattern) that no other devices will have image: TecO � After the shared context has been established, the two devices can open a direct communication link F. Ma. 27
Friedemann Mattern Crying When Lonely � If the two objects are too far apart (e.g., radio communication breaks down), the user is notified with an audible ”beep” Beep! Beep! image: TecO F. Ma. 28
Friedemann Mattern Application: Credit Card and Wrist Watch � Shake together before first use (establish friendship) � Credit card will only work when in proximity of watch F. Ma. 29
Friedemann Mattern Another Application: Poor Man’s Theft Alarm � Many mobile phones will be equipped with motions sensors � interaction feature for games � Shake sensor cube together with phone to activate the cube � no bottons etc. on the cube Sensor Cube � ”location limited channel” � feedback via phone � configuration via phone F. Ma. 30
Friedemann Mattern Poor Man’s Theft Alarm � Place cube on object to be protected � Receive alarm when cube is moved F. Ma. 31
Friedemann Mattern Poor Man’s Theft Alarm � Spontaneous networking with gateway station? � Raise alarm only when two or more sensor cubes report motion? � Deactivate when owner is nearby? F. Ma. 32
I nteracting with Smart Everyday Objects…
…Using RFI D (2)
Friedemann Mattern Making Things Smart w ith Electronic Labels (RFID) A paper label Identify objects with RFID inside from distance � small IC with RF-transponder Wireless energy supply � magnetic field (induction) An antenna, Read and write printed, etched a few 100 bits or stamped ... … and a chip „over the air “ attached to it � ~ 1 m … on a substrate e.g. a plastic foil F. Ma. 35
Friedemann Mattern Friedemann Mattern Smart Playing Cards � Playing cards have RFID labels � reader antenna is placed under the table � wireless transmission to player‘s PDA � Features: � count score � hints for beginners � determine winner � cheat alarm F. Ma. 36
Friedemann Mattern Simulating Smart Objects w ith “Virtual Counterparts” Identify objects here Implement all the smart behavior there F. Ma. 37
Friedemann Mattern Friedemann Mattern Virtual Counterparts of Playing Cards Hi, :...;;.;...,.:,.. :...;;.;...,.:,.. I‘m new here ;;.;.. :....,.:,.. ;;.;.. :....,.:,.. ;.. :.. ;;...,.:,.. ;.. :.. ;;...,.:,.. ;.. ...,:.. ;;.:,.. :...;;.;...,.:,.. ;.. ...,:.. ;;.:,.. ;;.;.. :....,.:,.. ;.. :.. ;;...,.:,.. ;.. ...,:.. ;;.:,.. F. Ma. 38
Friedemann Mattern Friedemann Mattern Cards as Personalities � Do playing cards have a memory? � What do they communicate? � How do they react to msgs? � How do playing cards interact with a backend system? � General infrastructure Alice in Wonderland F. Ma. 39
Friedemann Mattern Friedemann Mattern Softw are Infrastructure for Smart Objects? Hi, alert event I ‘m new here :...;;.;.... :...;;.;.... virtual ;;.;.. :..... ;;.;.. :..... ;.. :.. ;;...,. counterpart :...;;.;.... ;.. :.. ;;...,. ;.. ...,:.. ;;.;.. :..... ;.. ...,:.. :...;;.;.... ;.. :.. ;;...,. ;;.;.. :..... ;.. ...,:.. ;.. :.. ;;...,. ;.. ...,:.. F. Ma. 40
I nteracting with Smart Everyday Objects…
2D-Labels …Using (3)
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