ID A16C: Outfitting Embedded Devices with Low Power Wireless Communications

Design considerations for adding wireless communications to low power embedded devices

Shimon Gersten

CTO

Talon Communications

www.taloncom.com

14 October 2010Version: 1.0

2

Renesas Technology and Solution Portfolio

Microcontrollers& Microprocessors

#1 Market shareworldwide *

Analog andPower Devices#1 Market share

in low-voltageMOSFET**

Solutionsfor

Innovation

Solutionsfor

InnovationASIC, ASSP& Memory

Advanced and proven technologies

* MCU: 31% revenue basis from Gartner "Semiconductor Applications Worldwide Annual Market Share: Database" 25 March 2010

** Power MOSFET: 17.1% on unit basis from Marketing Eye 2009 (17.1% on unit basis).

33

Renesas Technology and Solution Portfolio

Microcontrollers& Microprocessors

#1 Market shareworldwide *

Analog andPower Devices#1 Market share

in low-voltageMOSFET**

ASIC, ASSP& Memory

Advanced and proven technologies

* MCU: 31% revenue basis from Gartner "Semiconductor Applications Worldwide Annual Market Share: Database" 25 March 2010

** Power MOSFET: 17.1% on unit basis from Marketing Eye 2009 (17.1% on unit basis).

Solutionsfor

Innovation

Solutionsfor

Innovation

44

Microcontroller and Microprocessor Line-up

Superscalar, MMU, Multimedia Up to 1200 DMIPS, 45, 65 & 90nm process Video and audio processing on Linux Server, Industrial & Automotive

Up to 500 DMIPS, 150 & 90nm process 600uA/MHz, 1.5 uA standby Medical, Automotive & Industrial

Legacy Cores Next-generation migration to RX

High Performance CPU, FPU, DSC

Embedded Security

Up to 10 DMIPS, 130nm process350 uA/MHz, 1uA standbyCapacitive touch

Up to 25 DMIPS, 150nm process190 uA/MHz, 0.3uA standbyApplication-specific integration

Up to 25 DMIPS, 180, 90nm process 1mA/MHz, 100uA standby Crypto engine, Hardware security

Up to 165 DMIPS, 90nm process 500uA/MHz, 2.5 uA standby Ethernet, CAN, USB, Motor Control, TFT Display

High Performance CPU, Low Power

Ultra Low PowerGeneral Purpose

55

Definitions

ISM – Instrumentation, Scientific & Medical bands. The 2.4GHz band is international.

LPW – Low Power Wireless. The ISM transmitted power allowed by various countries.

MAC – Media Access Control

RF – Radio Frequency

RTOS – Real Time Operating System

66

Sections

Components of LPW devices

Wireless protocols

Wireless demand on software

Wireless demands on power

Major selection criteria

Q & A

77

Components of LPW Battery Powered Devices – Typical

Antenna RF matching Radio MAC HW MCU Power control Battery

Typical LPW device

Antenna

RF matching& filtering

IC: Transciever+ MAC

Xtal

System Processor

Power control User IFLED, LCD, keys

Battery

88

Printed Antenna External Antennas

Components of LPW Devices

99

Embedded antennas Rechargeable battery

Components of LPW Battery Powered Devices

1010

RF module with Radio IF

Custom device

RF and MAC discrete

Antenna

RF matching& filtering

Discrete LNADiscrete Power

amplifier

Discrete Switch

Transceiver

MAC

Xtal

System Processor

Components of LPW Devices

1111

Network Processor RF module

Complete RF solution

API IF to MCU

Custom device

Network Processor

Antenna

RF matching& filtering

LNA Power amplifier

Switch

Transciever

MAC

MCU

Xtal

Xtal

System Processor

Components of LPW Devices

1212

RF module with integrated ICs for radio, Power amp and LNA, and matching.

Radio IF to MCU

Custom device

RF and MAC integrated

Antenna

RF matching& filtering

IC: Power amplifier+ LNA

IC: Transceiver+ MAC

Xtal

System Processor

Components of LPW Devices

1313

Antennas

Internal Wire Printed Chip

External Omni directional Directional

Components of LPW Devices

1414

Wireless Protocols – ISM bands

IEEE 802.11 – WiFi

Bluetooth – new LE

Zigbee – new SE 2.0 (6lowPAN)

802.15.4

ANT

Proprietary

1515

Wireless Protocols – Decision Making

Performance

Interoperability

Network Topology

Energy consumption

Time to market

Cost

1616

Wireless Protocols – Decision Making

Performance

Throughput – amount of payload per time

Latency – time it takes for a specific data item to arrive.

Reliability – odds of all data arriving up corrupted

1717

Interoperability

Wifi – MAC [.11a, .11b, .11g, .11n]Ethernet IEEE 802.3

Bluetooth – profiles [headset, printer, HID …]

BLE – profiles [healthcare, sports]

ZigBee – profiles [HA, Smart Energy, health …]

ANT+ - profiles [heartbeat, bicycle, scale …]

Proprietary – No Interop

Wireless Protocols – Decision Making

1818

Wireless Protocols – Decision Making

Network Topology

Point to point

Star – Hub point to many points

Peer to peer – Communicating pairs

Mesh - Any point, of many, to any- Networks nodes serve as routers

1919

Wireless Demand on Software

Sleep modes

Run-time efficiency

Co-existence with MAC

Share common resources

Power management

2020

Wireless Demand on Software

Share common resources

RTOS

Interrupts

Timers

RAM

Code space

Peripherals

2121

Wireless Demand on Power

Receiver ON time

Transmitter power

Bit rate

Error rate

Overhead

Wakeup time

2222

Major Selection Criteria

Wireless protocol

Level of RF integration

Power source

Enclosure

2323

Wireless protocol

This is usually the first criteria to apply. The selection of wireless protocol may affect:

Processor class [32,16 or 8 bit]RAM sizeCode size InteroperabilityPower requirementsDevice costTime to market

Major Selection Criteria

2424

Major Selection Criteria

Level of RF integration

This is both business and engineering criteria. The selection of fully integrated module vs. custom implementation depends on:

Performance requirementsPower limitationProjected volumeProduct maturityAvailable expertiseTime to marketProduce life and support

2525

RF Module Risk

2626

Level of RF integration – radio selection example:

  TI TI Atmel Nordic

 CC2400 CC2500

ATR2406

nRF24L01

         

cost @ 10K [$]3.60 @ 100

2.00 @ 100

3.00 @ 3K

2.00

max rate [Mbps] 1 0.5 1.152 2

max channels 84 168 95 126

RX at rate current [mA] 24 17 57 12.3

TX @ 0 dBm current [mA] 19 21.6 42 11.3

sleep current [microA] 1.5 0.4 1 0.9

standby current [microA]     22

RX sensitivity @ max rate [-dBm]

87 83 93 82

Modulation   MSK GFSK GFSK

sleep to up [mS]     0.25 1.5

standby to up [mS]       0.13

SPI max rate [Mbps]   6.5 10 8

carrier detection yes yes   yes

RSSI yes yes yes  

auto ACK       yes

auto retry   no yes

crystal [+/-PPM], [MHz]20,16 40,26

10,13.824

60,16

Major Selection Criteria

2727

Major Selection Criteria

Power source

This is both usability and engineering criteria. The selection of power source depends on:

Power requirements [mains, battery, harvested …]

Use case [no user access, available charger …]

Device dimensions [4 x 30 x 40mm]

Device weight [10 grams]

28 © 2010 Renesas Electronics America Inc. All rights reserved.

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Q & A

29 © 2010 Renesas Electronics America Inc. All rights reserved.

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Thank You!

www.taloncom.com