The Low Power Energy Aware Processing (LEAP) Embedded Networked Sensor System

Dustin McIntire, Bernie Yip, Hing Kei Ho, Lawrence Au, Dustin McIntire, Bernie Yip, Hing Kei Ho, Lawrence Au, Timothy Chow, and William J. KaiserTimothy Chow, and William J. Kaiser

UCLA Electrical Engineering DepartmentUCLA Electrical Engineering Department

Power Dissipation vs. Energy Efficiency

• High performance components often offer high efficiency

• …requires new architecture, enables new design approach

Benchmark Platform Execution TimeEnergy Relative Speed Relative EfficiencyPXA255 24.8us 12.9uJ 207.7 28.4ARM7 330us 49.2uJ 15.6 7.5Atmega 5.15ms 367uJ 1 1PXA255 325us 166.9uJ 516.9 70.7ARM7 4.8ms 699uJ 35 17.6Atmega 168ms 11.8mJ 1 1PXA255 94.5us 45.8uJ 153.4 20.4ARM7 1.2ms 187uJ 12.1 5Atmega 14.5ms 934uJ 1 1

FFT

CRC-32

FIR

802.11g ZigbeeChipset Atheros 5006XS CC2420Output Power 16dbm 0dbmPath LossRx Sensitivity (BER 10-5) -74dbm@48Mbps -90dbm@250KbpsTx Power (Max Output) 1320mW 57mWRx Power 924mW 65mWTotal Power 2.24W 122mWEffective Throughput 24Mbps 125KbpsEfficiency (nJ/bit) 93 976

90bB

Computing: ~ 20 - 70x

Networking: ~ 10x

Similar analogies in storage and sensing

LEAP Hardware Architecture

SPM(Slauson Processor Module)

EMAP (Energy Management and Accounting Preprocessor)

SPII2C

Vsense

Shutdown

x5 + 1

+ -

x2

Current SensedSupply Outputs + SPM Power (2A Max)

Sensor Inputs

USB Host

Flash

USB Host Controller

SDRAMPCMCIA

Address/Data

Sensor Voltage

Ethernet

JTAGGPIO

SDCard/MMC

MOSFET

Driver1

80

Pin

In

terb

oa

rd C

on

ne

cto

r

SYST

EM_V

IN

5.0_V

REG

3.3_V

REG

LEAP Design Course Platforms

• LEAP Approach– Diverse sensor systems– Fine grained platform instrumentation– Highly configurable testbeds

• Courses Require– Usage methods that support many

disciplines at the undergrad level– Rapid implementation of complex

algorithms

• National Instruments LabVIEW interfaces for LEAP– New National Instruments program:

courseware for shared development– Drag-and-drop Actions and Events– Integration of signal processing, control

systems, embedded networked sensing

LEAP Imager Node

Field of ViewOf

Trigger Sensor

Event GeneratorServer

ViewingObstacle

LEAP Software Tool Development:

The New LEAP2 Platform

• Dedicated ASIC performs EMAP functions

• Extensive current sensing and power domain controls

• Extendable to future modules through stacking bus

Address/Data Buffers

LEAP2 Module Block Diagram

512MB NAND Flash

GPIO/Serial Busses

Ethernet

CF

GPS

USB Host

SODIMM 200 Connector

uWatt FPGA

mPCI WLAN

CMOS Imager

Current Sensors

Sensor Power Switching

CC2420

EMAP ASIC

LEAP2 Stacking Connector

Low Power Radio Module

LEAP2 Stacking Connector

MSP430

Current Sensors

Current Sensors

Pw

r C

on

tro

l

ADC IF

Mem

Bu

s

Low Power Radio Module (LRM)

Host Processing Module (HPM)

EMAP2

Mini PCI Module (MPM)

Sensor Interface Module (SIM)

CMOS Imager Module (CIM)

8MB SRAM

64MB SDRAM

32MBNOR Flash

LEAP Research and Deployments

• New design approach based upon a component’s energy efficiency for each sensing task

• Energy efficiency of system components is paramount for long lived systems

• Energy profiling is vital for efficient use of system resources

• Completed and Planned deployments– Education (75+ users in class project setting) USC and UCLA– Ecosystem (acoustic localization, microclimate, multiscale sensing)– Aquatic (distributed contaminant sensing)– Seismic (rapidly deployable arrays, GEONet)