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iBadge V1.0

Contents:• Properties• Sensors• Bluetooth interface• Inferfacing iBadge• SW development• Energy monitoring• Speech processing• PCB / Enclosure

Presented by Ivo Locher

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Aim of iBadge

• Investigate behavior of children in a Kindergarten

• Research subject for embedded systems / position tracking / wireless networks /speech recognition

• Basis for further applications

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Properties of iBadge

• Speech recording / replaying• Position detection• Direction detection / estimation

(compass)• Tilt• Weather data: Temperature,

Humidity, Pressure, Light

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BlockdiagramiBadge

Data/Address

Bus

ADC8bit

ext. INT

RS232 Microcontroller

AVRATMEGA103L

Humidity

Light

Pressure

AccelerometerADXL202E

Magnetic fieldsensors

HMC1023

BluetoothEricsson

ROK101007

RadioRFM

TR1000

Ultra sound

ADC24bit

TemperatureDS2438

BatteryMonitorDS2438

PC Interface

CodecTLV320AIC10

Power supplycircuit

PowerSwitches

Battery3.6V

700mAh

ResetSwitch

LED

Sensors

duty cycle1-Wire bus

1.6V 3.3V 5V

comparator

SPIMcBSP

HostPort

DSPTMS320VC5416

Weather sensors

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iBadge components

ATMEGA 103L- 128kB Flash, 4kB SRAM, 4kB EEPROM- 4MHz Clock, 32kHz timer- QFP package

DSP TMS320VC5416- 64kB DA RAM, 64kB SA RAM, Harvard- 8MHz ext. clock, up to 160MHz internal clock (PLL)- flexBGA package

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Data exchange

• DSP Host-Port AVR address / data bus

• 8Bit• Hardware interrupt driven• Host-Port enables AVR to access

entire memory space of DSP

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Sensor specs

• Temperature- 16Hz Fs, -55 to +125oC, 0.25 K/LSB

• Battery current monitoring*- 16Hz, various resolutions: 0.626 – 2.44 mA/LSB

• Accelerometer**- 10Hz Fs, +/- 2g, duty cycle

• Microphone- 16kHz Fs, 16Bit/sample (Codec), 20kHz BW

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Sensor specs (cont’d)

• Position tracking (ultrasound, RFM)- 10Hz, 10cm resolution

• Weather sensors (humidity, pressure, light)**- 400Hz, analog

• Magnetic field*- 15Hz, +/- 6gauss, analog

* On board calibration / ** external calibration

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Sensor specs (cont’d)

Type of Sensors Sensor part # Utility Format Data type Proposed ThroughputAccelerometer ADXL202E Tilt respect to ground X.xx g int16 1 secMagnetic Sensor HMC1023 Orientation respect to earth magn. field X.xxx gauss int16 1 secHumidity Sensor HIH-3610-003 Ambient humidity XX% uint8 10 sec

Temp. Sensor DS2438 Ambient temperature XX.x oC int16 10 secPressure Sensor XFAM115KPA Barometric pressure XXXX hPA uint16 10 secLight Sensor CL9P4L Ambient light intensity XX% uint8 2 secMicrophone WM-61A Ambient sounds/speech 8 bit uint8 64kBit/sPosition Sensor US / RFM Position detecton via RFM via RFM 1 secBattery Power DS2438 Remaining battery power XXX.x mAh uint16 10 sec

Loudspeaker HPS16A Sound/Speech generation 8 bit uint8 64kBit/s

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interface

• Fc = 2.400 – 2.483 GHz• GFSK, BT = 0.5• Nominal output power = 0 dBm (1mW)• Frequency hopping with 79 channels• Approx 1Mb/s, TDMA, time slot=625 s• Distance: 10..30m (1mW)

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Bluetooth (cont’d)

• 1 Master, 7 Slaves• Asymmetric mode w/ 723.2kb/s

downlink, 57.6kb/s uplink (ACL)• Symmetric mode with 433.9 kb/s

(SCO)• 3 simultaneous synchronous voice

channels with 64kb/s

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Bluetooth (cont’d)

• EricssonROK 101 007

• ARM7-Thumb• Programmable• UART used

(460kB/s)• RFCOMM

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Interfacing iBadge

• Connector board- RS232 connection between PC, AVR, BT- JTAG interface toDSP debugging- free RS232 from/to AVR (i.e. for a terminal)

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Connector board (35x80mm)

TopBottom

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Interfacing with RS232

• 3 connections (RS232):- BT AVR- BT PC- PC AVR

Data/Address

Bus

RS232 Microcontroller

AVRATMEGA103L

BluetoothEricsson

ROK101007

PC Interface

SPIMcBSP

HostPort

DSPTMS320VC5416

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Connection

PC AVR- Download of AVR-SW and DSP-SW into Flash / EEPROM of AVR- Download-SW / cable provided by Atmel- File format: Intel HEX-File

- AVR-SW runs on TinyOS- AVR boots up DSP over Host-Interface

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Connection (cont’d)

• BT PC- configuring/programming of BT interface- download of a separate program running on the BT module- sending data from PC over BT

• BT AVR- normal running mode of iBadge- future: programming of AVR / DSP

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SW Development Scenario

• AVR-SW development on Atmel Compiler,testing / debugging over RS232

• DSP-SW development with TI Code Composer Studio,testing / debugging over JTAG interface

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Scenario (cont’d)

Stand-alone version:- DSP-SW must be included in AVR-SW (as binary array, *.abs)- AVR-SW (including DSP-SW) download over RS232 interface / storing in Flash on AVR- Boot up: AVR-SW starts / keeps DSP in reset- DSP-SW download over host interface (8 Bit) - DSP releasing from reset and DSP-SW starts

Data/Address

Bus

RS232 Microcontroller

AVRATMEGA103L

BluetoothEricsson

ROK101007

PC Interface

SPIMcBSP

HostPort

DSPTMS320VC5416

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Energy monitoring

• 4 Battery monitors:- Entire circuit - All sensors- DSP - Bluetooth

• On/off-switching of partial circuits:- All sensors - Only weather

sensors- DSP - Bluetooth

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Tree structure

DC-DC Converter

Switch SW1

Switch SW2

Switch SW3

DSP_L3

33nH

RFM_L5

33nH

ATMEGA_L2

33nH

Battery Monitor Battery Monitor

Battery Monitor

Battery Monitor

DSP_L2

33nH

RFM_L4

33nH

ATMEGA_L1

33nH

4V

3.3VBAT_VCC COM_VCC

BAT_GND COM_GND

DSP_VCC

SEN_VCC

BT_VCC

AVR_VCC

AVR_DVCC

AVR_AVCC

BT_DVCC

SEN_DVCC

SEN_AVCC

DSP_AVCC

DSP_DVCC

DSP_GND DSP_AGND

DSP_DGND

BT_DGND

SEN_DGND

SEN_AGNDSEN_GND

BT_GND

AVR_GND

AVR_DGND

AVR_AGND

DC-DC ConverterDSP_CORE_DVCC1.5V

Switch SW4WSEN_AVCC

Switching / battery monitors are controlled by AVR

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Battery

• Li-Ion• Voltage: 3.6V• Capacity: 700mAh (= 9kJ)

• Approx. battery life, when everything is on all the time: 3.5h

• estimated battery life for normal operation: 5.4h

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Motivation for Energy Monitoring

• Find optimal scheme what most energy efficient is, i.e.:- Codec:

speech compression/feature extraction vs transmitted data

computational power consumption

vs radio (BT) power consumption

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Motivation (cont’d)

• Run entire or parts of iBadge in a mode, which is most energy efficient.=> duty cycle (Sung Park)

tT

T

t

Power upPower down

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Speech processing

• Implementation of different Codecs G.722 (G.729, proprietary)

• Front-end processing of speech on iBadge

• Seamless switching between them

Energy efficiency / data rate / recognition rate

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Codec G.722

• Output data rate: 64kb/s• 7 kHz analog BW

QMF

ADPCM

ADPCM

MUX

16kHz16Bit

~7kHz BW

8kHz16Bit

8kHz16Bit

48kbit/s6Bit

16kbit/s2Bit

lower sub-band

higher sub-band

64kbit/s

Encoder

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PCB (62.5 x 47mm)

Top Bottom

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PCB (cont’d)

• PCB size: 62.5 x 47mm (same width as battery)

• 4 signal layers / 6 power planes with separate analog plane

• 0.006” tracks / 0.004” clearance• Additional small board (7mm),

perp. for acceleration sensor(z-axis)

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Enclosure

Prototype

Finally: a customized enclosure

•                        Pocket clip