SMART DUST K. Pister, J. Kahn, B. Boser (UCB) S. Morris (MLB) MEMSMTO DARPA

SMART DUST Goals Autonomous sensor node (mote) in 1 mm 3 MAV delivery Thousands of motes Many interrogators Demonstrate useful/complex integration in 1 mm 3

SMART DUST COTS Dust GOALS: Create a network of sensors Explore system design issues Provide a platform to test Dust components Use off the shelf components

SMART DUST COTS Dust - RF Motes Atmel Microprocessor RF Monolithics transceiver 916MHz, ~20m range, 4800 bps 1 week fully active, 2 N S EW 2 Axis Magnetic Sensor 2 Axis Accelerometer Light Intensity Sensor Humidity Sensor Pressure Sensor Temperature Sensor

SMART DUST COTS Dust - Network Simulation Cheap platforms --> Lots of nodes --> Network challenges!

SMART DUST Message Diffusion (McLurkin) Each mote checks all it’s received transmissions for the one with the maximum value The mote then rebroadcasts it with a lower value The result is a gradient pointing towards the signal source. Number Of Motes=200 Communications Range=.5

SMART DUST Edge Detection using Min/Max 1. Ask each or your neighbors how many motes they can see. 2. Find the minimum and maximum of these numbers 3. Share these minimum and maximum numbers with all your neighbors. 4. When all your neighbors have the same min.max info as you, compare your local neighbor count to this info. 5. Turn red if you are lonely Number Of Motes=500 Communications Range=.5

SMART DUST Gradient Directed Communication These gradients can be used to direct transmissions towards a single source Messenger Agents (the light blue dots) transmit themselves to motes with higher message levels This provides the minimum number of hops to get to a central destination Number Of Motes=150 Communications Range=1

SMART DUST Centroid Location Find edges Diffuse pheromone from the edges inward Find the lowest concentration using Min/Max sharing If you have the lowest concentration, turn yellow Number Of Motes=500 Communications Range=.8

SMART DUST Mote Position Estimation Give GPS receivers to some motes and callthem “BasisMotes”. Ask them to turn gray. Each BasisMote diffuses it’s own pheromone throughout the group The position of any other mote can be estimated from the levels of basis pheromones present.

SMART DUST Network Growing Since diffusion directed communication already minimizes number of hops, whatever are we going to optimize? We can use division of labor to optimize power (time) Certain motes are responsible for communications to the hub and others are responsible for sensing Number Of Motes=128 Communications Range=1

SMART DUST COTS Dust - Optical Motes Laser mote 650nm laser pointer 2 day life full duty CCR mote 4 corner cubes 40% hemisphere

SMART DUST CCR Interogator

SMART DUST Video Semaphore Decoding Diverged 300m Shadow or full sunlight Diverged 5.2 km In shadow in evening sun

SMART DUST Video Semaphore Decoding Diverged 300m Shadow or full sunlight Diverged 5.2 km In shadow in evening sun

SMART DUST 1 Mbps CMOS imaging receiver

SMART DUST Optical Communication (vs. RF) Pro: low power small aperture spatial division multiplexing high data rates LPI/LPD baseband coding Con: line of sight atmospheric turbulence

SMART DUST Turbulent Channel

SMART DUST Micro Mote - First Attempt

SMART DUST 2D beam scanning laser lens CMOS ASIC Steering Mirror AR coated dome

SMART DUST 6-bit DAC Driving Scanning Mirror Open loop control Insensitive to disturbance Potentially low power

SMART DUST Power and Energy Sources Solar cells Thermopiles Storage Batteries ~1 J/mm 3 Capacitors ~1  J/mm 3 Usage Digital control: nW Analog circuitry: nJ/sample Communication: nJ/bit

SMART DUST ’01 Goal

SMART DUST MAV Delivery 60 mph 18 min 1 mi comm Built by MLB Co.

SMART DUST Dust Delivery Floaters Autorotators solar cells Rockets thermopiles MAVs MOTE

SMART DUST Micro Flying Insect ONR MURI/ DARPA funded year 1 of 5 year project Dickinson, Fearing (PI), Liepmann, Majumdar, Pister, Sands, Sastry Heavily leveraged on Smart Dust

SMART DUST Applications DoD Battlefield sensor networks Sensor mine-fields, burrs and fleas Traffic mapping Captured terrain surveillance Bunker mapping... Civilian High speed/low power IRDA Interactive virtual ballet...

SMART DUST The (somewhat) Virtual Keyboard

SMART DUST Data from ACC-glove

SMART DUST Conclusion Cubic inch motes off-the-shelf, ~$100 Dec ’99: 100 node network in Soda/Cory Desperately need intelligent software Millimeter-scale motes Dec ’00: first working prototypes Don’t have a clue what we need in software