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.
28
Q & A
29 © 2010 Renesas Electronics America Inc. All rights reserved.
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Thank You!
www.taloncom.com