Design of a Versatile LowDesign of a Versatile Low-cost ... · PDF fileSource: Texas Instruments Inc. ... ZigBee - APS, ZDO - Profiles - Tree, Mesh ... 1 CCP File 220 Lines of Code

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Design of a Versatile Low-costDesign of a Versatile Low-cost IEEE 802.15.4 Module

for Long Term Battery Operationfor Long Term Battery Operation

Ale ander Klapproth Stefan Kna th and Rolf KistlerAlexander Klapproth, Stefan Knauth and Rolf KistlerHTA Luzern - Lucerne University of Applied Sciences

CEESAR - Centre of Excellence for Embedded Systems Applied Research

EuZDC 2007 Lucerne University of Applied Sciences / www.CEESAR.ch Slide 1

Contact: Prof. A. Klapproth [email protected] +41 41 349 3512

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CEESAR Research Center

Center of Excellence for Embedded Systems Applied ResearchLucerne University of applied Sciences

Building & Home Automation

Embedded Control and Realtime

Wireless

Indoor Localisation

Lowpower-Lowcost Solutions.

Strong background in research & development cooperations with industry partners

Researchproject funding possible depending on topic risks and goals


Researchproject funding possible depending on topic, risks and goals

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Overview

Zi B f th hfire & smoke

detector

ZigBee for the aware home

motion detector

i d t l

energy monitoring & control

heating / cooling

door controlwindow control

control

lighting control

remote control

Benefits:> more comfort> less energy consumption> enhanced security


Source: Texas Instruments Inc.

> enhanced security

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Contents

Design of a Versatile Low-cost IEEE 802.15.4 Modulefor Long Term Battery Operationfor Long Term Battery Operation

Introduction

Hardware Components

DesignDesign

Applications


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Requirements

Initial Vision: Autonomous Radio Device for Sensor Applications

Low-Power Durability >= 10 Years, Stand-aloneDurability 10 Years, Stand alone

SmallMinimal FootprintMinimal Footprint

OpenStandards based on PHY/MAC layers fullStandards based on PHY/MAC layers, full access to resources, freely programmable

Low CostLow-CostFor large quantities (>25’000 pieces/year)Production cost < 10 €


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Make or Buy?

M k (RF IC S C) if• Make (RF-IC, SoC) if– High quantities– Medium/long term project– High cost pressure– Sophisticated system requirements– Have access to required competence

and supportand support– Full application integration

B (M d l ) if• Buy (Module) if– Low quantities (typically <20k units)– Short time-to-market

L i i i l– Low initial costs– Basic system requirements– Lack of RF competence

>> Depends on the project, requirements and company >> Looking at the requirements: Make

EuZDC 2007 Lucerne University of Applied Sciences / www.CEESAR.ch Slide 6Source Criteria: Texas Instruments Inc., Cirronet

>> Looking at the requirements: Make

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Building Blocks

Interface Periperals, GPIOs…Antenna

RF-ICMCUPower Source Balun,

Match FeedFirmware MatchFirmware

CLK Source


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SoC, SIP, RF-IC, NwkProc?SoC

• SoC (System-on-Chip)– Usually results in smaller footprint– Close coupling of MCU and RF-IC Stack, Application

SoC

MCU, RF-IC

Close coupling of MCU and RF IC • less overhead• good performance/power consumption

Small number of external components

, pp

SIP

MCU RF-IC– Small number of external components– Simple system design – Low system bill-of-materials costs

Stack, Application

MCU RF IC

• MCU/RF-IC Tandem– Flexibility

• Use ”your processor” and environment

MCU/RF-IC

MCU RF-ICUse your processor and environment

• Choose the RF frontend you like– RF-IC may have better radio characteristics

H b id S t

Stack, Appl.

NwkProcessor• Hybrid Systems: – Network Processor -> ZigBee on ”RF-IC”– SIP -> MCU & RF-IC in one package Appl

MCU RF-IC

Stack


p gnot on same die Appl. Stack

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SoC/SIP: Selection Criteria (1)


There are a lot (of differences)

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SoC/SIP: Selection Criteria (2)Takking the speccific reqquirem

ents!


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Antenna: Types (1)

Chip Whip PCB

1. Size

2. Cost

3. Performance

Remarks - Assembly, fitting, mounting

Design crucial, orientation issues

Chip antennas have a reasonable performance compared to their size


performance compared to their size

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Antenna: Fractus Chip Antenna

• Performance Criterias– High, stable Bandwith– Good omnidirectional radiation patternGood omnidirectional radiation pattern– Reasonable Gain– High Efficiency

St bl I d– Stable Impedance

• Fractal Technologygy– Space-Filling, multiple-scale geometries– Performance optimisation of

multilayer antennasy– Standard materials and processes

• Other chip antanna provides• Other chip antanna provides– Antenova: http://www.antenova.com/– Rainsun: http://www.rainsun.com/


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Balun, Match & Feed Line

B l F d• Balun– Ballanced to Unballanced– General: Achieve compatibility between

Feed

p ytwo components or systems

– Here: Convert the differential SoC RF output to the single-ended antenna

Balun

• Match– ZSoC RF out= ZAntenna = 50 Ω

N ti t hi i it d d Balun– No active matching circuit needed• Feed Line

– ZSoC RF out= ZFeed = ZAntenna = 50 Ω

Match

Balun

ZSoC RF out ZFeed ZAntenna 50 Ω– Feedline must have 50 Ω

Can be realised with surface microstripspand/or as passive electric circuits (LC).

Trade off between number of components


pand footprint

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Feed Line

Calculate the dimensions of the microstrip


Freeware AppCAD from Agilent: http://www.hp.woodshot.com

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Energy Source

• Lithium Battery Cell– Standard Component

• Used in Photocameras

– High Energy DensitiySufficient Discharge Current– Sufficient Discharge Current

• Coin cells can‘t provide 27mA

– Low self discharging constantg g– No voltage regulation needed– Easy to fit (solder flags)

• Alternatives– Ambient energy harvesting– Accumulators, super capacitors– Inductive energy transmission


– …

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Layout

2 4 GH HF D i R l– Ground planes

• The bigger the planes the better

2.4 GHz HF Design…Rules

gg p• Solid ground plane below the chip

– Vias• Close to decoupling capacitorsp g p• Vias on the ground pad under the chip• Several vias to connect layer grounds

– Componentsp• Place two coils 90° to each other• Use exact same values

– Microstripp• Distance 2 times it‘s width from anything• Length min. Lambda / 4

– Antenna• Move away from circuitry• Antenna clearance zones

EuZDC 2007 Lucerne University of Applied Sciences / www.CEESAR.ch Slide 16Sources: Texas Instruments Inc., Fractus

Follow the reference designs!

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Verification

HF design needs to be verifiedHF design needs to be verified

Return Loss

Span 200 MHzSpan 500 MHz

Radiation Pattern

HorizontalVertical

Packet BurstRadiation

FrequencySpectrum


Span 500 MHz Vertical

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Software: ZigBee, IEEE or Proprietary?

Options Pros Cons

- NWK only - Multi-hop routing - Ressource usage

ZigBee- APS, ZDO- Profiles

- Tree, Mesh- Mgmt. Functions- Interoperability

- Execution time- Packet overhead-Licensingp y g

- Simple MACReduced MAC

- Node addressing PAN associateion

- Not ZigBeeNo NWK Layer

IEEE MAC

- Reduced MAC- Full MAC

- PAN associateion- Channel Access- Security

- No NWK Layer- Packet overhead

- Acknowledges- 802.15.4 compliant

From very i l t f ll

- Fits 100% the i t

- You cannot i t ith

IEEE PHYsimple to fully featured

requirements communicate with anyone else- Development time for high-level


gfeatures

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Software: Low Power

N l ith t t SW“

• Use SW controlled hardware features

„No low power without smart SW“

– Chose appropriate power mode– Stop CPU during RF RX/TX– Adapt the output power– Switch to internal RC oscillator

when radio is not used– Turn off analog radio part

Sh t d i h l– Shut down peripherals– Execute code from RAM

• Optimise data transmission protocol– Minimise RF TX/RX on time– Optimise packet length– Consider data patterns– Burst data if possible– Consider power availability if unevenly

distributedU MAC t l f t (b

EuZDC 2007 Lucerne University of Applied Sciences / www.CEESAR.ch Slide 19Source: TI/Chipcon Design Note DN103

– Use MAC protocol features (beacon, polling, short addresses, intra PAN bit…)

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Application: KISS Temperature Sensor

• Send a temperature value to a collector every 10 min.y

• Optimised for Low Power• Star Topology• Small number of nodes• Simple IEEE 802.15.4 frames

– No channel access– Random Sleeping time + RC osc.– One way transmission (no ACKs)One way transmission (no ACKs)– No transmission checks

• Internal temperature sensor• About 20 years lifetime

(not proved yet)


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Application: Power Point Page Flipper

• Flip the PowerPoint slidesusing WeBee 3W B 3 id• WeBee 3 side– KISS Temperature Application

PC Side

IEEE 802.15.4

• PC Side– USB dongle from

http://www.integration.com USBIA OEM DAUB1 2400– Access on IEEE 802.15.4 or

ZigBee level using WindowsPC

USB

USB Dongle Drv.g ee e e us g do sDLL

– Receive Message, find PowerPoint Window and

ZigBee DLL

Custom WindowsPowerPoint Window andsend Windows NotificationMessagePC: 1 CCP File 220 Lines of Code P P i t

Custom Windows Application

Windows MSG


– PC: 1 CCP File, 220 Lines of Code Power Point

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Thank you!

CEESAR @ Lucerne University of Applied Sciences

Embedded systems applied research Industry research partnerEmbedded systems applied researchUPnP Wireless / IEEE802.15.4 / ZigBeeLow resource platforms / Java on 8 Bit

Industry research partnerPartner for research consortia

www.ceesar.ch


Low resource platforms / Java on 8 BitLocalisation

www.ceesar.ch

Documents

Design of a Versatile LowDesign of a Versatile Low-cost ... · PDF fileSource: Texas Instruments Inc. ... ZigBee - APS, ZDO - Profiles - Tree, Mesh ... 1 CCP File 220 Lines of Code