1 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Smart Sensor Architecture
Smart Sensor System Architecture in Mimosa project
Iiro Jantunen / Nokia Research Center
Tutorial Ambient Intelligence,
Toulouse, March 10, 2006
2 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Contents
•What is a smart sensor system?
• Transducer, analog electronics, ADC , digital electronics
•Open architecture for smart sensors• BluLite
• Public S S I protocol
• nanoUDP/nanoIP networking
• O pen API:s for developing applications for using smart sensors
•Mimosa architecture for smart sensors• Wired & wireless BluLite or R FID connection
• Many sensors in many devices over many radio technologies
3 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
From sensors to smart sensors
S ensor
Active sensor (S T 3-axis accelerometer)Wireless smart sensor
Passive sensor (photodiode)
4 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Smart Sensor Systems
• C ombine functions of sensors and interfaces
• S ensing
• Amplification
• S ignal conditioning
• AD conversion
• Bus interfacing
• Include higher level functions
• S elf-testing
• Auto-calibration
• Data processing and evaluation
• C ontext awareness
• C ommunications
• Modularity and/or integration
• Transducer• physical reality → electrical
measurable
• Amplifier & filtering• sensor impedance, signal strength
and quality
• Analog-digital conversion
• Microcontroller / DS P / AS IC• Digital signal processing
• C ommunications to outside world
• Networking• S erial interface (US B, S PI, MMC )
• R adio interface (optional)
5 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Transducer
• C onverts between physical properties
• The resulting property can be
• E lectrical capacitance
• C urrent
• Voltage
• Optical power
• E lectrical measurand needs an amplifier/filtering circuit to provide electrical power, impedance etc.
• O ptical measurand needs a optoelectrical transducer with the same properties
R eluctance, optoelectronic, ultrasonic, radar
Displacement, position, proximity
Tuned laser & optoelectronic
G as concentration
OptoelectronicR adiation
C apacitiveS ound, pressure
C lock signalTime
G PSLocation
R esistive, capacitiveHumidity
PiezoresistiveForce
Pressure differenceF low
Piezoelectric, capacitiveAcceleration
Typical/common
techniques
Measurement
6 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Non-ideal behavior of sensors
S tore value and correctTemp. dependence of sensitivity
S tore value and correctTemperature dependence of offset
F ilterModifyUnsuitable frequency response
R educe power useIncrease coolingS elf-heating
BufferUnsuitable output impedance
AmplifyIncreaseLow sensibility
AmplifyIncreaseLow resolution
PredictableHysteresis
S tore value and correctC alibrateC ross-sensitivity to temp and strain
R educeNonrepeatability
Auto-rangeTime dependence of sensitivity
Auto-zeroMinimizeTime dependence of offset
C alibrate/reduceC alibrateOffset
C ompensateMinimizeDrift
R educeC onsistentNonlinearity
MC U/DS PS ensor InterfaceS ensor DesignC haracteristic
From R . F rank: Understanding Smart S ensors , 2n ed.,
7 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Amplifying and analog filtering of sensor output
Issues:
• S ignal conditioning
• S ignal transmission
• Data display
• O perating life
• C alibration
• Impedance of sensor and system
• S upply voltage
• Frequency response
• F iltering
• Amplifier provides signal strength and sensor impedance
• F iltering needed to suppress noise
• If needed, quite complex functions can be done with analog electronics, but many functions are better done in digital electronics
• easier
• cheaper
• need less room
8 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Analog-digital conversion (ADC)
• The measurement must usually be changed to digital form for
• further processing and calculations
• storing to memory
• sending the data
• or just an economical reason
• ADC often included in MC U:s, e.g. MS P430F1xx
• Is the resolution (8 or 12-bit) enough?
Issues:
• S ample rate
• R esolution (8, 12, 16-bit)
• Accuracy
• Power consumption
• Price
9 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Digital signal processing
• More complex signal processing
• summing many sensors (e.g. 3-axis accelerometers)
• pattern recognition, e.g. step counters, speech recognition
• C an be done in
• AS IC , for cheap mass-production
• DS P, for high-speed number crunching
• MC U (microcontroller), medium level calculations, control software
Issues:
• F ixed-point vs. floating-point DS P
• Data precision
• S peed
• Power usage
• Price
• Internal ADC
• Need for flexible programming: MC U vs. DS P
• Programming languages: Assembly vs. C /C ++ or J ava
10 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Microcontroller
• S oftware controlling a smart sensor system, e.g.
• measurements• communications• data memory• real time clock
• Usually includes • ADC (DAC )• timers• serial ports (S PI, I2C , UAR T)• flash memory
• Power-efficient, cheap, flexible• Also called MC U or µC
MS P430F169 by Texas Instruments
• Low supply-voltage 1.8 - 3.6 V • Ultra-low power consumption:
• Active: 330 µA at 1 MHz, 2.2 V• S tandby: 1.1 µA• Off (R AM retention): 0.2 µA
• Wake-up from standby in less than 6 µs • 16-Bit R IS C , 125-ns instruction cycle• Program memory 60 kB (flash), R AM 2048 B• 8-channel 12-Bit ADC with internal reference,
sample-and-hold and autoscan• Dual channel 12-Bit DAC with synchronization • 16-Bit Timer_ A & Timer_ B with 3/7 C C R• On-chip comparator • 2 serial interfaces: UAR T or S PI or I2C ™• S upply voltage supervisor/monitor• Brownout detector • Bootstrap loader • S erial onboard programming
11 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Networking sensors over radio
GPRS/3Gnetwork
Internet
C ellular
GPRS/3GnetworkGPRS/3Gnetwork
InternetInternet
C ellular
RFIDRFID
UWB
Bluetooth
Low E ndWLAN
12 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
BluLite (or Bluetooth Low End Extension)
• Low E nd E xtension for Bluetooth is designed• to complement Bluetooth by creating a wireless solution that• allows small devices that are limited in battery power, size, weight and cost to have a wireless
connection with mobile terminals• without adding yet another radio to mobile terminals (as Z igBee)
• Optimized for irregular data exchange between Bluetooth enabled mobile terminals and button cell batter powered small devices
• C oncept assumes two device classes• Dual-mode (Bluetooth 1.2 with Low E nd mode) for terminals• S tand-alone (Low E nd mode alone) for sensors and enhancements
CommonHost
IF
Dual-mode device (i.e. terminal) Stand-alone device(e.g. 3D accelometer node)
BluetoothBB/MAC
LEE MAC/(BB)Common
RFSensorASIC
LEEASIC
Stand-alone device(e.g. fitness gadget)
SensorASIC
LEEASIC
13 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
BluLite radio
2400 2401 2402 2403 2481 2482 24832480
Bluetooth channelsChannels of theproposed system
IEEE 802.11b channelin North America and Europe
2403 2406 2433 2436 248124782463 2466
One default initialization channel, non-overlapping with Bluetooth
Two secondary initialization channels, for jamming resistance
24 Unicast channels for user data
MHz
MHz
Low End Extension channels
14 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
BluLite radio parameters with 1 Mbps
•Physical bit rate 1 Mbps
•Frequency band 2.4 G Hz (IS M band)
•Duplex TDD
•C o-existence of multiple devices• C onnection setup channel C S MA
• Data delivery F DMA
•J amming avoidance FDMA
•PDU payload• Byte aligned, variable length, max 255 bytes
•Bit rate excluding PHY and MAC overheads
• Uni-directional with AR Q , max 890 kbps
• Bi-directional with AR Q , max 2 x 471 kbps
15 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Basic functions of BluLite radio
1. ADVE RTIS E : Makes the local device visible and connectable to all remote devices within reach. Low-power protocols optimized for this state. A possibility for an application dependent trade-off between connection set-up delay and the power consumption.
2. S C AN: R eturns the addresses and short description of the advertising remote devises within reach.
3. C ONNE C T: E stablishes a point-to-point connection with an advertising remote device. 4. C ONNE C TE D: Provides point-to-point bi-directional data delivery with error detection,
AR Q, segmentation, role switch and a low-activity mode. An evolution path to point-to-multipoint, requiring additions only in master capable devices.
OFF IDLE
CONNECT
SCAN
ADVERTISE
CONNECTED
16 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Symbian
POP
1. Host (N6630)
M-API
Applicationspace
SSI (Client)
SSI (virtualServer)
CommunicationLayer (U-ULIF)
RFID (front end)
Sensors
Digital sensormanagement
(memory map)
RFID Sensor
2. SEMBO
CART
SPI
SSI server
UART SPI/IIC DA
3. Sensor-HW
MSP430
FPGA
5. RF-module
Radio BBs
Device drivers
MCU
ADC DAC
SPI
4. LOCOS
1.
SSI server
UART SPI/IIC DA
2. Sensor-HW
MSP430
M-SPI
FPGA
BT LEE
4. LEE ASIC
Radio sensor node
1.3.
ULIFDevice drivers
M-SPI
nanoIP
Symbian
POP
1. Host (N6630)
M-API
Applicationspace
SSI (Client)SSI (Client)
SSI (virtualServer)
SSI (virtualServer)
CommunicationLayer (U-ULIF)
RFID (front end)
Sensors
Digital sensormanagement
(memory map)
RFID Sensor
2. SEMBO
CART
SPI
SSI server
UART SPI/IIC DA
3. Sensor-HW
MSP430
FPGA
5. RF-module
Radio BBs
Device drivers
MCU
ADC DAC
SPI
4. LOCOS
1.
SSI server
UART SPI/IIC DA
2. Sensor-HW
MSP430
M-SPI
FPGA
BT LEE
4. LEE ASIC
Radio sensor node
1.3.
ULIFDevice drivers
M-SPI
nanoIP
SSI server
UART SPI/IIC DA
2. Sensor-HW
MSP430
M-SPI
FPGA
BT LEE
4. LEE ASIC4. LEE ASIC
Radio sensor node
1.3.
ULIFDevice drivers
M-SPI
nanoIP
Mimosa Architecture
Internet
Back-end server
UMTSG PR S
17 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Simple Sensor Interface (SSI) protocol
• A simple protocol for reading smart sensors over, e.g., BT LE E
• Also provided for R FID sensor tags • Memory map of sensor data on
• C ompatible with IS O 18000-4
• S upport for multiple sensors on multiple devices
• S upport for data polling or streaming
• Developed in co-operation withS uunto, Vaisala, Mermit, C E A-LE TI, O ulu University and Ionific
• Development of the specification keeps backward compatibility (v0.4-)
• For specifications, source code and discussion forum, visit http://ssi-protocol.net
• C lient-server architecture
• Terminal has client software
• S ensor unit has server software
• C lient can
• poll sensors
• ask the server (Observer) to stream data to client (Listener)
• read and modify the configuration of the server
• C ommands have two forms
• C apital letter (“N”), no checksum
• Low case (“n”), the payload has a C R C checksum
18 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
SSI v1.0 command base
Free data
E rror
S treaming data
Read data
C onfiguration
S ensor discovery
F ree data for custom purposes⇮0x46 / 0x66F / f
E rror messages⇮0x45 / 0x65E / e
S ensor listener created→0x4A / 0x6AJ / j
R equest sensor listener←0x4C / 0x6CL / l
Delete sensor observer→0x4B / 0x6BK / k
S ensor observer created←0x59 / 0x79Y / y
C reate sensor observer→0x4F / 0x6FO / o
S ensor data response with one byte status field←0x44 / 0x64D / d
S ensor data response←0x56 / 0x76V / v
R equest sensor data→0x52 / 0x72R / r
S et configuration data for a sensor→0x53 / 0x73S / s
C onfiguration data response←0x58 / 0x78X / x
G et configuration data for a sensor→0x47 / 0x67G / g
R eset S S I device→0x5A / 0x7AZ / z
Discovery reply←0x4E / 0x6EN / n
Discover sensors→0x43 / 0x63C / c
Query reply←0x41 / 0x61A / a
Query→0x51 / 0x71Q / q
DescriptionDir.C ommand
19 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Example SSI command: Discovery reply
• S ensor device answers to Discovery command sent by a mobile terminal
• Discovery R eply message contains information about one or more sensors.
• The device answers with its address, command name (N or n) and sensor data
• E ach sensor is identified with• S ensor Id – 2bytes
• Description – 16 byte AS C II
• Unit – 8 byte AS C II
• Type – 1 byte
• S caler - signed 1 byte
• Min – minimum sensor reading value
• Max – maximum sensor reading value
• The reply can carry either one sensor per N command or many depending on buffer size
• UAR T or nanoIP frame provides the information about the length of a single message
Client Server
C
. . .
Terminal Sensor unit
N (sensor info )
N (sensor info )
Addr N/n
1 1
Sensor Id 1
2
Sensor desc.
16
Unit
8
Type Scaler
1 1
. . .MIn Max
44
20 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
nanoIP networking
• An open-source networking architecture
• Minimal overheads
• Wireless networking
• Local addressing
• NanoIP makes use of the MAC address of underlying network technology rather than IP addresses
• Used with nanoUDP (User Datagram Protocol) or nanoTC P (Transmission C ontrol Protocol)
• nanoUDP does not provide reliability or ordering
• nanoTC P provides retransmissions and flow control
• Mimosa uses nanoUDP
• http://www.cwc.oulu.fi/nanoip/
ULIF (BluLiteMAC )
nanoIP
nanoUDP
S S I
21 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Open source SSI/nanoIP implementation
• S S I v0.4 over nanoUDP/nanoIPprovided by O ulu University
• S S I v1.0 (nanoUDP/nanoIP) being finalized by Nokia R esearch C enter, will be open source
• Works over BluLite (Bluetooth LE E )
• 1 byte protocol type (nanoIP)
• 4 bytes nanoUDP header
• 2 byte payload + C R C length
• 1 byte S ource port (40 for S S I)
• 1 byte Destination port (40 for S S I)
• n bytes
• S S I payload
• 2 bytes
• optional C R C checksum
Prtcol PayloadLenH LenL CRC
1 11 n 2
Source
1
Dest.
1
22 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Mimosa API’s for 3 rd parties
MIMO S A Local C onnectivity Layer
MIMO S A S ensor Layer
MIMO S A C ontext Awareness Layer
MIMO S A Ambient User Interface Layer
LC _ API
S ensor_ API
C ontext_ API
UI_ API
Back-end server
Local MIMO S A S W ApplicationsIP
J ava & C ++ implementation
23 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Sensor Management Board
• C ontrols the sensors (host)
• C ontrols the sensors and BTLE E (S ensor R adio Node)
• R eal time clock (with its own battery)
• C onnectors for• LOC OS and/or C AR T
• S ensor board (UAR T, S PI/I2C , general digital I/O , 8-channel analog)
• J TAG programming interface
• Debugging ports (UAR T)
• IR Q ports
• MC U runs S S I/nanoIP and device drivers for sensors
24 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Sensor Management Board
• C ontrols the sensors (host)
• C ontrols the sensors and BTLE E (S ensor R adio Node)
• R eal time clock (with its own battery)
• C onnectors for• LOC OS and/or C AR T
• S ensor board (UAR T, S PI/I2C , general digital I/O , 8-channel analog)
• J TAG programming interface
• Debugging ports (UAR T)
• IR Q ports
• MC U runs S S I/nanoIP and device drivers for sensors
text
32.7
68 k
Hz
crys
tal
8 M
Hz
crys
tal
SEMBO
MCUMSP430F169
US
AR
T0
US
AR
T1
Deb
uggi
ng:
SP
I0 +
U
AR
T1
IRQ
sJT
AG
CA
RT
Real time clock
DS1305E
32.768 kHz crystal
3V BAT
SEPPO / SENSOR BOARD
LOCOS and / or CART
I2C
M-SPI
3.3 V POWER
UART
I2C
UART
3.3 V POWER
Ext
erna
lpo
wer
AD
C
DA
C
SPI
ANALOG
32.768 kHz clock
UART
25 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Mimosa terminal
• Nokia 6630 phone as terminal
• Attached electronics (C AR T, LO C O S , S E MBO , R F) provide the Mimosa hardware functionality
• J ava software on N6630 will provide the user interface, context awareness, sensor management etc.
• LO C O S board as motherboard of attached electronics
• S E MBO provides local sensor control
• S E PPO (or other) sensor board connected to S E MBO with a standard interface
• R F part controlled with F PG A on LO C O S on baseband-module
• S eparate R F module
SEMBO
CART
SPI
SSI server
UART SPI/IIC DA
Sensor-HW
MSP430
FPGA
RF-module
Radio BBs
Device drivers
MCU
ADC DAC
SPI
LOCOSSEMBO
CART
SPI
SSI server
UART SPI/IIC DA
Sensor-HW
MSP430
FPGA
RF-module
Radio BBs
Device drivers
MCU
ADC DAC
SPI
SEMBO
CART
SPI
SSI server
UART SPI/IIC DA
Sensor-HW
MSP430
FPGA
RF-module
Radio BBs
Device drivers
MCU
ADC DAC
SPI
LOCOS
26 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Mimosa terminal - 2
SEPPO
SEMBO
LOCOS
CART
Connection to RF board
Connection to phone
27 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Sensor Radio Node
• S mart sensor which can be read over BT LE E connection
• E MMI board provides Bluetooth LE E for communications with mobile terminals
• S E MBO for controlling BT LE E , running the S S I server and sensor drivers
• LO C O S acts as motherboard
• S E PPO (or other) as sensor hardware board via standard connector
• UAR T
• S PI / I2C
• 8 analog channels
• 15 unspecified digital I/O pins
M-SPI
SSI server
UART SPID
A
Sensor-HW
MSP430
M-SPI
FPGA
BT LEE
LEE ASIC
Device drivers
LOCOS
SEMBO
EMMI
M-SPI
SSI server
UART SPID
A
Sensor-HW
MSP430
M-SPI
FPGA
BT LEE
LEE ASICLEE ASIC
Device drivers
LOCOS
SEMBO
EMMI
28 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Sensor Radio Node - 2
LOCOS SEMBOEMMI
SEPPO
29 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Sensors demonstrated on Mimosa platform
I2C
Amplified analog
Amplified analog
Amplified analog
Digital
Interface
Fraunhofer-IS IT, C E A-LE TI, S TMicroelectronics
G yroscope
F itness & healthFraunhofer-IS IT, C ardiplus, Åmic
Lactate, glucose
F itness & health, streaming data over S S I/nanoIP/BluLite
C ardiplusE C G
F itness & healthNokiaFat %
Weather station, S S I demonstration
Nokia, (S ensirion, Intersema)
Humidity, temperature, pressure
NotesProviderS ensor
30 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Weather station
• Demonstration of S S I use
• Weather information: Temperature, Humidity / dew point, and Pressure
• Intersema MS 5534A pressure sensor
• Pressure range 300-1100 mbar
• Internal 15 Bit ADC
• 6 coeff. software compensation on-chip
• 3-wire serial interface
• 1 system clock line (32.768 kHz)
• 35 ms measurement time
• S ensirion S HT11 humidity sensor
31 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Weather station
• Demonstration of S S I use
• Weather information: Temperature, Humidity / dew point, and Pressure
• Intersema MS 5534A pressure sensor
• S ensirion S HT11 humidity sensor
• Internal 14-bit ADC
• Fully calibrated
• Internal power regulation
• R ange
• Humidity 0 – 100 %
• Temperature -40 – 128°C
• 2-wire serial interface (not I2C )
• 11/55/210 ms for a 8/12/14bit measurement.
32 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Fat percentage
• Actually measures body water content (TBW)
• From TBW, fat-% and dehydration (∆TBW) calculated
• 4-point measurement of impedance with 50 kHz signal
• Amplified analog output
• Low-noise OPA2350 two-channel
• Also used for 2-point measurement of surface impedance, G alvanic S kin R esponse (G S R )
• S kin stratum corneum humidity
• S tress measurement
AN
ALO
G IN
TE
RF
AC
E E
LEC
TR
ON
ICS E1
SIGNAL IN
E2M1
E3M2
E4SIGNAL OUT
C50KHZ
GND
+3.3V
FAT_CS
V_FAT
I_FAT
REF_FAT
AD
C
SE
MB
O
INT
ER
FA
CE
33 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Lactate & glucose sensors
• Fraunhofer-Institut fürS iziliziumtechnologie (Itzehoe, G ermany) makes the sensor
• Åmic (Uppsala, S weden) makes a needle array to penetrate outer layer of skin
• Measures the lactate or glucose content of interstitial fluid
• Lactate and glucose sensors differ only on the enzyme used
• Amplified analog connection to S E MBO
34 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
RFID sensor tag
•Virtual server on the terminal device answers to the S ensor API when connecting to R FID sensors
•Virtual server translates the commands to the R FID reader to read a specified memory area of the tag
•0x53 (for AS C II “S ”) in address 0x0C (Tag memory layout) defines the memory layout to be S S I compliant
•Memory mapping designed for one or more sensors per tag
•Memory layout designed to be convenient for S S I use
User data (layout defined by S S I).0x12 –
Tag memory layout. This defines tag to be S S I compliant sensor.0x0C – 0x116
Tag hardware type0x0A – 0x0B
Tag manufacturer0x08 – 0x094
Tag ID0x00 – 0x078
FieldBytes
35 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
RFID memory mapping: Sensor data space
Optional configuration data or 2nd sensorn bytes0x3E –n
Not defined yet. Could be, e.g., time needed before sensor value is valid.
3 bSensor control0x3B – 0x3D
0x01Bits 0 – 7 will be written by the reader to request the tag to write the sensor data
1 bActivate sensor0x3A
4
0x00000064Maximum value the sensor can provide.4 b HEXMaximum value0x36 – 0x39
0x00000000Minimum value the sensor can provide.4 b HEXMinimum value0x32 – 0x358
“C”Constant unit description. 8 b ASCIIUnit0x2A – 0x318
“Temperature”Constant sensor description16 b ASCIISensor description0x1A – 0x2916
For future use. Could be, e.g., number of sensors.
1 bEmpty0x19
0x01Sensor status. Bits 0 – 7 indicate if the sensor values are valid data (bit = 1) or not yet valid (bit = 0).
1 b HEXStatus0x18
0x001 b HEXMultiplier0x17
0x01Describes the type of the Sensor value (0x00 = float, 0x01 = signed integer…)
1 b HEXType 0x16
0x00000014Variable sensor value4 byte HEXSensor value0x12 – 0x15
8
ExampleDescriptionTypeField nameByte address
36 © 2006 Nokia S mart S ensor Architecture.ppt / 2006-03-10 / IJ
Questions & Answers