Low Power Wireless Sensor Module
Ultra low power IEEE 802.15.4 compliant wireless sensor module
Humidity, Light, and Temperature sensors with USB
Product Description
Tmote Sky is an ultra low power wireless module for use in sensor networks, monitoring applications, and rapid application prototyping. Tmote Sky
leverages industry standards like USB and IEEE 802.15.4 to interoperate seamlessly with other devices. By using industry standards, integrating humidity, temperature, and light sensors, and providing flexible interconnection with peripherals, Tmote Sky enables a wide range of mesh network applications. Tmote
Sky is a drop-in replacement for Moteiv’s successful Telos design. Tmote Sky includes increased performance, functionality, and expansion. With TinyOS support out-of-the-box, Tmote Sky leverages emerging wireless protocols and the open source software movement.
Tmote Sky is part of a line of modules featuring on-board sensors to increase robustness while decreasing cost and package size.
Key Features
• 250kbps 2.4GHz IEEE 802.15.4 Chipcon Wireless Transceiver
• Interoperability with other IEEE 802.15.4 devices
• 8MHz Texas Instruments MSP430 microcontroller (10k RAM, 48k Flash)
• Integrated ADC, DAC, Supply Voltage Supervisor, and DMA Controller
• Integrated onboard antenna with 50m range indoors / 125m range outdoors
• Integrated Humidity, Temperature, and Light sensors
• Ultra low current consumption
• Fast wakeup from sleep (<6μs)
• Hardware link-layer encryption and authentication
• Programming and data collection via USB
• 16-pin expansion support and optional SMA antenna connector
• TinyOS support : mesh networking and communication implementation
• Complies with FCC Part 15 and Industry Canada regulations
• Environmentally friendly – complies with RoHS regulations
Low Power Wireless Sensor Module
Table of Contents
Product Description...1
Key Features...1
Table of Contents...2
Module Description ...3
Power ...4
Typical Operating Conditions ...4
Mechanical Characteristics ...5
Block Diagram...6
Schematic ...7
Microprocessor ...9
Description ...9
Typical Operating Conditions ...9
PC Communication ...9
Programming...10
Block Diagram...12
Radio...13
Description ...13
Typical Operating Conditions ...14
Measured Output Power ...14
Antenna...15
Internal Antenna without Battery Pack ...15
Internal Antenna with Battery Pack ...15
Radiation Pattern ...16
External Flash ...17
Typical Operating Conditions ...17
Flash Hardware Write Protection ...18
Sensors...19
Humidity/Temperature Sensor ...19
Light Sensors ...20
Expansion Connector...21
Internal Temperature and Voltage Monitoring...23
Agency Certification ...24
FCC Certification...24
OEM Labeling requirement ...24
FCC Notices...25
General Information ...25
Document History...26
Product Status Definitions...26
Disclaimer ...27
Address Information ...28
Headquarters ...28
Low Power Wireless Sensor Module
Module Description
The Tmote Sky module is a low power “mote” with integrated sensors, radio, antenna, microcontroller, and programming capabilities.
USB Connector
User Button
Reset Button
Photosynthetically Active Radiation
Sensor
(optional) Total Solar Radiation
Sensor (optional)
10-pin expansion connector 6-pin expansion
connector
Internal Antenna
CC2420
Radio SMA
Antenna Connector
(optional) Humidity
Temperature Sensor (optional)
USB Transmit LED
USB Receive LED LEDs
USB Microcontroller
Digital switch Isolating USB from
microcontroller JTAG
connector USB
Connector
User Button
Reset Button
Photosynthetically Active Radiation
Sensor
(optional) Total Solar Radiation
Sensor (optional)
10-pin expansion connector 6-pin expansion
connector
Internal Antenna
CC2420
Radio SMA
Antenna Connector
(optional) Humidity
Temperature Sensor (optional)
USB Transmit LED
USB Receive LED LEDs
USB Microcontroller
Digital switch Isolating USB from
microcontroller JTAG
connector
USB Flash (2kB)
ST Code Flash (1MB) Texas Instruments
MSP430 F1611 microcontroller
32kHz oscillator
48-bit silicon serial ID 2-pin SVS
connector
USB Flash (2kB)
ST Code Flash (1MB) Texas Instruments
MSP430 F1611 microcontroller
32kHz oscillator
48-bit silicon serial ID 2-pin SVS
connector
Figure 1 : Front and Back of the Tmote Sky module
Low Power Wireless Sensor Module
Power
Tmote Sky may be powered by two AA batteries. The module was designed to fit the two AA battery form factor. AA cells may be used in the operating range of 2.1 to 3.6V DC, however the voltage must be at least 2.7V when programming the microcontroller flash or external flash.
If the Tmote Sky module is plugged into the USB port for programming or communication, it will receive power from the host computer. The mote operating voltage when attached to USB is 3V. If Tmote will always be attached to a USB port, no battery pack is necessary.
The 16-pin expansion connector (described in the Section on page 17) can provide power to the module. Any of the battery terminal connections may also provide power to the module. At no point should the input voltage exceed 3.6V—doing so may damage the microcontroller, radio, or other components.
Typical Operating Conditions
MIN NOM MAX UNIT
Supply voltage 2.1 3.6 V
Supply voltage during flash memory programming 2.7 3.6 V Operating free air temperature -40 85 oC Current Consumption: MCU on, Radio RX 21.8 23 mA Current Consumption: MCU on, Radio TX 19.5 21 mA Current Consumption: MCU on, Radio off 1800 2400 μA Current Consumption: MCU idle, Radio off 54.5 1200 μA Current Consumption: MCU standby 5.1 21.0 μA
Caution! ESD sensitive device.
Precaution should be used when handling the device in order to prevent permanent damage.
Low Power Wireless Sensor Module
Mechanical Characteristics
r e v o c t o n o d
; a n n e t n a d r a o b - n O
1 4 5
6
2 3
s l a i r e t a m g n i t c u d n o c h t i w
3 6 1 . 3
0 8 5 . 2 7
6 2 . 1
6 5 2 .
3 1 5 .
Tag X Y Size Notes
1 0.183 0.099 Ø 0.090 Mounting hole, do not use metal fixture 2 2.454 0.099 Ø 0.090 Mounting hole
3 2.454 1.151 Ø 0.090 Mounting hole
4 0.755 0.162 Ø 0.066 Pin 1 of 10-pin 0.1in rect IDC connector 5 1.099 0.163 Ø 0.066 Pin 1 of 6-pin 0.1in rect IDC connector 6 2.139 0.909 Ø 0.034 Pin 1 of 8-pin 2mm rect JTAG connector
Figure 2 : Physical dimensions of Tmote Sky.
All units are in inches unless otherwise noted.
MIN NOM MAX UNIT
Width 1.24 1.26 1.29 in
Length 2.55 2.58 2.60 in
Height (without battery pack and SMA antenna) 0.24 0.26 0.27 in
Low Power Wireless Sensor Module
Block Diagram
CC2420 Radio 2.4 GHz
IEEE 802.15.4 compliant PCB
Antenna
SMA Coax
4
2
6
2
UART[0] 2
2 I2C[0]
6 ADC[0-3,6-7]
4 GPIO
Humidity Temperature
Sensor PAR Sensor
TSR Sensor
ADC[4]
ADC[5]
I/O Power
SPI I/O
4
Power
Reset User
10-pin + 6-pinIDC header
SVSin SVSout TI MSP430 Microcontroller
UART[1]
P1.1/P2.2 Reset
TCK SPI[0] P1[0,3,4]
P4[1,5,6]
SPI[0]
I2C[0]
Silicon Serial ID 1-wire
7 JTAG 8-pin JTAG
2mm IDC header SVS 2-pin
IDC header
USB 2.0 UART/RS232 Functionality RX/TX RTS/DTR
JTAG Write Protection
ST Flash 1024k (2.7V)
Figure 3 : Functional Block Diagram of the Tmote Sky module, its components, and buses
Low Power Wireless Sensor Module
Schematic
5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
VCCin
LED1 RESET
LED2
LED3 DVCC
HUM_SCL
AVCC
RADIO_SO
RADIO_SI FLASH_CS
ADC4
ADC0 ADC1
UART0RX UART0TX I2C_SCL I2C_SDA GIO1
ADC6 ADC7
VCCin
GIO2 GIO3
SVSin SVSout
P_DVCC
DVCC RADIO_SCLK FLASH_HOLD UART1TX
P_DVCC
ADC2
FLASH_HOLD
FLASH_CS
GIO2
ADC2
RADIO_SO
ADC5 DAC0 ADC6
HUM_SDA
ADC0
SVSin ADC7
ADC1GIO1
HUM_SCL
ADC4
LED2
UART1RX
UserINT
RESET GIO3
ADC3
DVCC
TMS TDO
HUM_PWR
HUM_SDA UART0TX
TCK LED3
UART0RX
GIO0
AVCC I2C_SDARADIO_SI
TDI SVSout
UART1RX
HUM_PWR
ADC5
LED1
I2C_SCLRADIO_SCLK
UART1TX
SVSout
1Wire
DVCC DVCC
1Wire DVCC
RESET TMS
DVCC
DVCC
TDI TDO
TCK DVCC
DVCC
UserINT
UserINT RESET
ADC3 GIO0
ADC0
RADIO_CS
RADIO_GIO0 RADIO_GIO1
RADIO_SFD RADIO_RESET RADIO_VREF_EN
DVCC
P_DVCC
VCCin RESET
PKT_INT UART1TX
RADIO_SCLK RADIO_SO RADIO_SI
UART1RX
TMS TDI TDO
TCK
OFFPAGELEFT-L
Title
Size Document Number Rev
Date: Sheet of
(c) Copyright 2004: UC Berkeley, 2006: Moteiv B
Tmote Sky
B
1 3
Thursday, May 11, 2006 Title
Size Document Number Rev
Date: Sheet of
(c) Copyright 2004: UC Berkeley, 2006: Moteiv B
Tmote Sky
B
1 3
Thursday, May 11, 2006 Title
Size Document Number Rev
Date: Sheet of
(c) Copyright 2004: UC Berkeley, 2006: Moteiv B
Tmote Sky
B
1 3
Thursday, May 11, 2006 OPTIONAL
FLASH MCU
SENSORS POWER
LEDS
OPTIONAL OPTIONAL
DAC0 TimerA Capture
EXPANSION
MOUNTING HOLES RESET SWITCH
USER SWITCH
Prev Flash Pwr
DMAE0 DAC1/SVSin
ACLK
Nonplated near antenna
JTAG
SERIAL ID By default, R_VREF connects to ground.
If R_VREF is moved to adjacent pins, external voltage reference may be connected to ADC0; in that case ensure that ADC0 is configured as an IO pin in the input direction.
R7
470 R7
470 R10
10k R10 10k
J10 J10
11
R16
0 open R16
0 open R1
100k R1 100k
D6 Blue Clear - 404-1028-1-ND
D6 Blue Clear - 404-1028-1-ND
1 2
R14
0 open R14
0 open R5
5.1M R5 5.1M
R2 2.2k R2 2.2k
U5
M25P80 U5
M25P80 1 S 2 Q 3 W 4 VssHOLDVccDC 5678
J11 J11
11
SW2
EVQ-P2K02Q SW2
EVQ-P2K02Q
1 2
U0
TI_MSP430_F1611 U0
TI_MSP430_F1611 1 DVcc
P6.3/A3 2
P6.4/A4 3
P6.5/A5 4
P6.6/A6/DAC0 5
P6.7/A7/DAC1/SVSIN 6
Vref+
7
8 XIN XOUT/TCLK 9
VeREF+
10 Vref-/VeREF- 11
P1.0/TACLK 12
P1.1/TA0/BSLTX 13
P1.2/TA1 14
P1.3/TA2 15
P1.4/SMCLK 16
P1.5/TA017 P1.6/TA118 P1.7/TA219 P2.0/ACLK20 P2.1/TAINCLK21 P2.2/CAOUT/TA0/BSLRX22 P2.3/CA0/TA123 P2.4/CA1/TA224 P2.5/Rosc25 P2.6/ADC12CLK/DMAE026 P2.7/TA027 P3.0/STE028 P3.1/SIMO0/SDA29 P3.2/SOMI030 P3.3/UCLK0/SCL31 P3.4/UTXD032 P3.5/URXD0 33 P3.6/UTXD1 34 P3.7/URXD1 35 P4.0/TB0 36 P4.1/TB1 37 P4.2/TB2 38 P4.3/TB3 39 P4.4/TB4 40 P4.5/TB5 41 P4.6/TB6 42 P4.7/TBCLK43 P5.0/STE1 44 P5.1/SIMO1 45 P5.2/SOMI1 46 P5.3/UCLK1 47 P5.4/MCLK 48
P5.5/SMCLK49
P5.6/ACLK50
P5.7/TBoutH/SVSOUT51
XT2OUT52
XT2IN53
TDO/TDI54
TDI55
TMS56
TCK57
RST/NMI58
P6.0/A059
P6.1/A160
P6.2/A261
AVss62
DVss63
AVcc64
R9
100 R9
100 R15
0 open R15
0 open
C2 0.1u C2 0.1u
R12 100k 1%
R12 100k 1%
U9
DS2411 U9
DS2411 1 I/OVcc 2
GND 3
J12 J12
11
D4
Red Clear - 404-1017-1-ND D4
Red Clear - 404-1017-1-ND
1 2
C5 0.1u C5
0.1u L2
F Bead 240-1035-1 L2 F Bead 240-1035-1
1 2
R_VREF 0Ohm jumper R_VREF 0Ohm jumper
1 2
3
GND X0
32kHz GND X0
32kHz 1 2 3
C1 0.1u C1 0.1u
U7
2pin Header - 2mm U7
2pin Header - 2mm
1 1 2 2
R8
220 R8
220
C3 10uF C3 10uF
D5
Green Clear - 404-1021-1-ND D5
Green Clear - 404-1021-1-ND
1 2
U2
10pin Header - 0.1"
U2
10pin Header - 0.1"
1 1 22
3 3 44
5 5 66
7 7 88
9 9 1010
D2 S1087 Photodiode D2 S1087 Photodiode
D3 S1087-01 Photodiode D3 S1087-01 Photodiode
ROSC 2.2k
ROSC 2.2k C4
0.1u C4 0.1u
R4 470k R4 470k U4
PWR_CONN U4
PWR_CONN + 1 - 2
C6 0.1u C6 0.1u U8
8pin Header - 2mm U8
8pin Header - 2mm
1 1 22
3 3 44
5 5 66
7 7 88
C9 0.1u C9 0.1u SW1
EVQ-P2K02Q SW1
EVQ-P2K02Q
1 2
HUMIDITY/
TEMP SENSOR U3
SHT11 HUMIDITY/
TEMP SENSOR U3
SHT11 SCLK3 4 VCC
1 GND SDA2
U28
6pin Header U28
6pin Header
1 1 22
3 3 44
5 5 66
R11 100k 1%
R11 100k 1%
Low Power Wireless Sensor Module
5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
D D V A _ K 4 2 C C
3 D D V D _ K 4 2 C C D
D V A _ K 4 2 C C
D D V D _ K 4 2 C C
CC24K_AVDD CC24K_DVDD3
CC24K_AVDD
D D V D _ K 4 2 C C
D D V D _ K 4 2 C C
3 D D V D _ K 4 2 C C
CC24K_DVDD
3 D D V D _ K 4 2 C C D
D V D _ K 4 2 C C D
D V A _ K 4 2 C C
3 D D V D _ K 4 2 C C
3 D D V D _ K 4 2 C C
CC24K_AVDD
T E S E R _ O I D A R
D F S _ O I D A R
C C V D
0 O I G _ O I D A R
T N I _ T K P
O S _ O I D A R
K L C S _ O I D A R
I S _ O I D A R
S C _ O I D A R
1 O I G _ O I D A R N E _ F E R V _ O I D A R
D D V D _ K 4 2 C C
e l t i T
v e R r
e b m u N t n e m u c o D e z i S
t e e h S :
e t a
D of
y e l e k r e B C U : 4 0 0 2 t h g i r y p o C ) c
( B
s o l e T
B
3 2 4 0 0 2 , 9 2 r e b m e t p e S , y a d s e n d e W
4 . 5 1 . 2 0 8 0 2 4 2 C
C WirelessRadio z
H G 4 . 2 t a
n o i t a l o s i
0 5 e s u ohmtraces
z H G 4 . 2 matchingnetwork
s m h o 0 5 o t d e h c t a m
1 8 L
% 5 n 5 . 7
1 2
3 L
1 - 5 3 0 1 - 0 4 2 d a e B F
1 2
1 8 3 C
0 p n
% 5 p 2 2 1 X
f p 6 1 - Z H M 6 1 4
8 C n 0 1
1 A
T N A _ B C P _ 0 2 4 2 C C
123
7 C u 1 . 0
1 6 L
% 5 n 5 . 7
1 2 6 8 C p 8 6
3 7 C
0 p n p 5 2 . 0 - / + p 6 . 5
1 2
3
6 7 4 R k 0 1 2
8 C p 8 6
2 7 4 R m 1 2
6 L
% 5 n 6 . 5
1 2
7 8 C
u 1 .
0 C8
u 1 . 0 3
8 C p 8 6
3 7 4 R m 1
1 8 C
0 p n p 5 2 . 0 - / + p 5 . 0
0 1 U
0 2 4 2 C C D R U A G _ O C 1 V
O C V _ D D V 2 A
E R P _ D D V 3 A
1 F R _ D D V 4 A
D N 5 G
P _ F 6 R
H C T I W S _ X R X 7 T
N _ F 8 R
D N 9 G
W S _ D D V 0 A 1
C 1 N 1
C 2 N 1
NC13 AVDD_RF214 AVDD_IF215 NC16 AVDD_ADC17 DVDD_ADC18 DGND_GUARD19 DGUARD20 RESETn21 DGND22 DSUB_PADS23 DSUB_CORE24 3 . 3 D D V
D 25
8 . 1 D D V
D 26
D F S 27
A C C 28
P O F I F 29
O F I F 30
n S C 31
K L C S 32
I S 33 O S 34
M A R _ D D V
D 35
C N 36
AVDD_XOSC1637
XOSC16_Q238
XOSC16_Q139
NC40
VREG_EN41
VREG_OUT42
VREG_IN43
AVDD_IF144
R_BIAS45
ATEST246
ATEST147
AVDD_CHP48
X E _ D N 9 G 4 5
8 C u 1 . 0
4 7 4 R k 0 1 2
A A M S RF1GND2GND3GND4GND5
4 6 C
<
R S E w o L F u 0
1 5ohm
1 6 C 0 p n p 5 2 . 0 - / + p 5 . 0
5 7 4 R 0
1 9 3 C
0 p n
% 5 p 2 2
1 5 4 R
% 1 k 3 4
1 7 C
r 5 x
% 0 1 p 6 . 5
5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
U_VCC
U_VCC
U_AVCC
U_VCC3.3 USB+
USB- USB- USB- USB- USB- USB-
U_VCC
VCCin
RTS U_VCC U_VCC3.3
P_DVCC
RXD TXD
P_DVCC
DTR
RXD P_DVCC
P_DVCC UART1TX
TXD UART1RX
DVCC
DCD RI DSR
DCD
DVCC
RTS DTR
RESET TCK
TCK DVCC DSRRI
TMS TDI TDO TCK
P_DVCC
U_VCC U_VCC EECS
EESK EEDATA
VCCin P_DVCC
UART1TX
UART1RX DVCC
USB5V
DVCC
RESET TCK TMS TDI TDO TCK
Title
Size Document Number Rev
Date: Sheet of
(c) Copyright 2004: UC Berkeley, 2006: Moteiv B
Tmote Sky
B
3 3
Thursday, April 06, 2006 Title
Size Document Number Rev
Date: Sheet of
(c) Copyright 2004: UC Berkeley, 2006: Moteiv B
Tmote Sky
B
3 3
Thursday, April 06, 2006 Title
Size Document Number Rev
Date: Sheet of
(c) Copyright 2004: UC Berkeley, 2006: Moteiv B
Tmote Sky
B
3 3
Thursday, April 06, 2006 Used for Reading Serial / Programming
Connects and Powered via USB
USB INTERFACE
I/O BUFFER
MOTE POWER USB POWER FILTER
USB Interface
RESET SEQUENCE RECOGNITION
USB IDENTIFICATION EEPROM
U23
93C46 U23
93C46 1 CS 2 SK 3 DIN
4 DOUT GND 5
NC 6 NC 7 VCC8 C23
0.1u C23 0.1u
R27 2.2k R27 2.2k
R29 10k R29 10k
U27 ADG715BRU
U27 ADG715BRU
5S1S2 7S3 9S4 11S5 14S6 16S7 18S8
20 D8 19
D7 17 D6 15 D5 13 D4 12 D3 10 D2 8 D1 6 3SDA 1SCLK
24A0 22A1
VCC2 GND4
VSS21
23RST
C25 10u C25 10u
U25 TC55RP33 U25 TC55RP33
GND1
Vin2 3 Vout
D22
LLSD103A D22
LLSD103A
1 2
U22
USB A U22
USB A 44 33 22 11
L20 F Bead 240-1035-1 L20 F Bead 240-1035-1
1 2
R26 100 R26 100
D21
Red Clear - 404-1017-1-ND D21
Red Clear - 404-1017-1-ND 1 2
R31 10k R31 10k D20
Green Clear - 404-1021-1-ND D20
Green Clear - 404-1021-1-ND 1 2 R25 100 R25 100 C21
33n C21 33n
C24 0.1u C24 0.1u
U20
FT232BM U20
FT232BM 3V3OUT 6
USBDM 8
USBDP 7
RSTOUT#
5 RESET#
4 27XTIN
XTOUT 28 32EECS
1 EESK EEDATA 2 31TEST
AGND29 GND9 GND17 SLEEP# 10 PWREN# 15 PWRCTL 14 RXLED#TXLED#TXDEN111216 RI# 18 DCD# 19 DSR#13DTR#CTS#RTS#VCCIORXDTXD 202122232425
VCC26
VCC3
AVCC30
C22 0.1u C22 0.1u C20
0.1u C20 0.1u
R20 470
R20 470
R24 1.5k R24 1.5k
U29 NC7WZ126
U29 NC7WZ126
11OE
21A 1Y6
72OE
52A 2Y3
Vcc8Gnd4
R28 10k R28 10k
Figure 4 : Schematics for the Tmote Sky module
Low Power Wireless Sensor Module
Microprocessor
Description
The low power operation of the Tmote Sky module is due to the ultra low power Texas
Instruments MSP430 F1611 microcontroller featuring 10kB of RAM, 48kB of flash, and 128B of information storage. This 16-bit RISC processor features extremely low active and sleep current consumption that permits Tmote to run for years on a single pair of AA batteries. The MSP430 has an internal digitally controlled oscillator (DCO) that may operate up to 8MHz. The DCO may be turned on from sleep mode in 6μs, however 292ns is typical at room temperature.
When the DCO is off, the MSP430 operates off an eternal 32768Hz watch crystal. Although the DCO frequency changes with voltage and temperature, it may be calibrated by using the 32kHz oscillator.
In addition to the DCO, the MSP430 has 8 external ADC ports and 8 internal ADC ports. The ADC internal ports may be used to read the internal thermistor or monitor the battery voltage.
A variety of peripherals are available including SPI, UART, digital I/O ports, Watchdog timer, and Timers with capture and compare functionality. The F1611 also includes a 2-port 12-bit DAC module, Supply Voltage Supervisor, and 3-port DMA controller.
The features of the MSP430 F1611 are presented in detail in the Texas Instruments MSP430x1xx Family User’s Guide available at http://ti.com/msp430.
Typical Operating Conditions
MIN NOM MAX UNIT Supply voltage during program execution 1.8 3.6 V Supply voltage during flash memory programming 2.7 3.6 V Operating free air temperature -40 85 oC Low frequency crystal frequency 32.768 kHz Active current at Vcc = 3V, 1MHz 500 600 μA Sleep current in LPM3 Vcc = 3V, 32.768kHz active 2.6 3.0 μA
Wake up from LPM3 (low power mode) 6 μs
PC Communication
Tmote Sky uses a USB controller from FTDI to communicate with the host computer. In order to communicate with the mote, the FTDI drivers must be installed on the host. FTDI provides drivers for Windows, Linux, BSD, Macintosh, and Windows CE. These drivers are included on the Moteiv CD shipped with your order. Windows users will need the Virtual Com Port (VCP) drivers. They may also be downloaded from FTDI’s website at: http://www.ftdichip.com/
Tmote Sky appears as a COM port in Windows’ device manager (or as a device in /dev in Linux, OSX, and BSD). Multiple Tmote Sky motes may be connected to a single computer’s USB ports at the same time. Each mote will receive a different COM port identifier. In the example below, one Tmote is connected and assigned COM6 “USB Serial Port”.
An application may read from Tmote Sky by opening the COM port assigned to the Tmote Sky mote. Tmote communicates with the host PC through USART1 on the TI MSP430.
Low Power Wireless Sensor Module
Figure 5 : Device Manager showing Tmote Sky installed as COM6
The motelist command line utility lists all of the Tmote Sky motes currently connected to a computer. This utility optionally lists previously connected motes that the system has cached.
Invoke motelist with the -h option for more information.
> motelist
Reference CommPort Description
--- --- --- M49WD0S6 COM6 Moteiv tmote sky
NOTE: Tmote Sky uses an I2C digital switch to prevent unwanted conventional serial port signals from reaching the TI microcontroller. The I2C protocol must be implemented and sent over the RTS and DTR lines in order to obtain direct access between the Tmote Sky and USB controller. The UART lines do not use the I2C switch allowing direct
communication (but not programming or JTAG) without additional software.
Programming
The Tmote Sky module is programmed through the onboard USB connector. A modified version of the MSP430 Bootstrap Loader, msp430-bsl, programs the microcontroller’s flash.
Tmote has a unique hardware circuit that prevents the mote from spuriously resetting. This hardware circuit makes it necessary to have a special sequence sent to the module in order to program it.
By invoking msp430-bsl, verify you have the patched BSL by looking for the “telos” keyword.
Version 1.39-telos-7 or later is required for Tmote Sky.
> msp430-bsl
MSP430 Bootstrap Loader Version: 1.39-telos-7 Use -h for help
Low Power Wireless Sensor Module
To communicate with Tmote Sky, the MSP430 Bootstrap Loader requires a set of options to provide the proper signals to the microcontroller to initiate programming. For convenience, the options have been folded into a single Tmote flag:
--tmote
To program a Tmote Sky module on COM3 (or /dev/ttyUSB2 in Linux) with an application image named app.ihex, invoke the MSP430 Bootstrap loader with the following options.
> msp430-bsl --tmote -c 2 -r -e -I -p app.ihex MSP430 Bootstrap Loader Version: 1.39-telos-7 Mass Erase...
Transmit default password ...
Invoking BSL...
Transmit default password ...
Current bootstrap loader version: 1.61 (Device ID: f16c) Changing baudrate to 38400 ...
Program ...
2742 bytes programmed.
Reset device ...
If you are using TinyOS, it has support for programming Tmote Sky. After compiling your application, you may install it with the following command
> make tmote install.x bsl,n
Where x is the 16-bit address assigned to the mote and n is the COM port that Tmote Sky is currently using. Note that not including “bsl” or “bsl,n” will program automatically using the bsl to the first Telos mote found on the USB bus using the motelist command.
For more information about the options in the MSP430 Bootstrap loader, invoke msp430-bsl with the -h option to display the help information.
Motelist and msp430-bsl are available from Moteiv Corporation at http://www.moteiv.com in the “Support” section.
NOTE: msp430-bsl starts counting from 0, but COM ports in Windows start counting at 1.
If Tmote Sky is connected to COM3 in Windows, you must program it using “-c 2” or
“bsl,2” when invoking msp430-bsl. In Linux, Tmote Sky will appear as /dev/ttyUSB2 and may be programmed using “-c 2” or “bsl,2”.
Low Power Wireless Sensor Module
Block Diagram
Oscillator System
Clock 32kHz
ACLK SMCLK
CPU 16 bit 16 reg multiply
Flash RAM
12-bit ADC 8 Channels
<10μs Conv
12-bit DAC 2 Channels
16-bit bus
I/O Port 3/4 16 I/Os I/O Port 1/2
16 I/Os Interrupts
I/O Port 5/6 8 I/Os
MCLK
Watchdog Timer 15/16 bit
Timer A 3 CC reg
Comparator A Timer B
7 CC reg
USART0 UART
SPI I2C DMA
Controller 3 Channels
USART1 UART
SPI
CC2420 Radio Interrupts & SPI
PC UART via USB
Figure 6 : Block diagram of the TI MSP430 microcontroller and its connection to other peripherals in the Tmote Sky module
Low Power Wireless Sensor Module
Radio
Description
Tmote Sky features the Chipcon CC2420 radio for wireless communications. The CC2420 is an IEEE 802.15.4 compliant radio providing the PHY and some MAC functions. With sensitivity exceeding the IEEE 802.15.4 specification and low power operation, the CC2420 provides reliable wireless communication. The CC2420 is highly configurable for many applications with the default radio settings providing IEEE 802.15.4 compliance. Features and usage of the CC2420 is available in Chipcon’s datasheet at http://www.chipcon.com
The CC2420 is controlled by the TI MSP430 microcontroller through the SPI port and a series of digital I/O lines and interrupts (see the Schematics on page 7 for more information). The radio may be shut off by the microcontroller for low power duty cycled operation.
The CC2420 has programmable output power. Common CC2420 register values and their corresponding current consumption and output power are shown in Figure 7.
PA_LEVEL TXCTRL register Output Power [dBm] Current Consumption [mA]
31 0xA0FF 0 17.4
27 0xA0FB -1 16.5
23 0xA0F7 -3 15.2
19 0xA0F3 -5 13.9
15 0xA0EF -7 12.5
11 0xA0EB -10 11.2
7 0xA0E7 -15 9.9
3 0xA0E3 -25 8.5
Figure 7 : Output power configuration for the CC2420
The CC2420 provides a digital received signal strength indicator (RSSI) that may be read any time. Additionally, on each packet reception, the CC2420 samples the first eight chips, calculates the error rate, and produces a link quality indication (LQI) value with each received packet. A mapping from RSSI to the RF level in dBm is shown in Figure 8.
Figure 8 : Received Signal Strength Indicator mapping to RF Power [dBm]
Low Power Wireless Sensor Module
Typical Operating Conditions
MIN NOM MAX UNIT Supply voltage during radio operation (Vreg on) 2.1 3.6 V Operating free air temperature -40 85 oC
RF frequency range 2400 2483.5 MHz
Transmit bit rate 250 250 kbps
Nominal output power -3 0 dBm
Programmable output power range 40 dBm
Receiver sensitivity -90 -94 dBm
Current consumption: Radio transmitting at 0 dBm 17.4 mA Current consumption: Radio receiving 19.7 mA Current consumption: Radio on, Oscillator on 365 μΑ Current consumption: Idle mode, Oscillator off 20 μΑ Current consumption: Power Down mode, Vreg off 1 μΑ Voltage regulator current draw 13 20 29 μΑ Radio oscillator startup time 580 860 μs
Measured Output Power
The RF output power of the Tmote Sky module from the CC2420 radio is shown in Figure 9.
For this test, the Tmote Sky module is transmitting at 2.405GHz (IEEE 802.15.4 channel 11) using the O-QPSK modulation with DSSS. The CC2420 programmed output power is set to 0 dBm. The measured output power of the entire modulated spectrum is 2.4 dBm.
2.4 2.401 2.402 2.403 2.404 2.405 2.406 2.407 2.408 2.409 2.41
−50
−45
−40
−35
−30
−25
−20
−15
−10
−5 0
Frequency (GHz)
Output power (dBm)
RWB: 100 kHz VWB: 100 kHz Sweep: 50ms
Figure 9 : Measured RF output power over the modulated spectrum from the Tmote Sky module
Low Power Wireless Sensor Module
Antenna
Tmote Sky’s internal antenna is an Inverted-F microstrip design protruding from the end of the board away from the battery pack. The Inverted-F antenna is a wire monopole where the top section is folded down to be parallel with the ground plane. Although not a perfect
omnidirectional pattern, the antenna may attain 50-meter range indoors and upwards of 125- meter range outdoors. Measurements of the internal antenna’s performance with and without a battery pack are show in Figure 10 and Figure 11. Approximate radiation patterns for the Inverted-F antenna as provided by Chipcon AS are shown in Figure 12 and Figure 13.
Internal Antenna without Battery Pack
2004/11/25 Thr 14:44:06
CH2 S11 SMITH(R+jX) FS 1.000
MKR 3: 2.483 958 333GHz 65.166 4.083
Cor
3:2.483 958GHz 65.041 4.227 270.843pH 2:2.450 000GHz 39.757 -4.623 14.050pF 1:2.400 000GHz 40.014 -40.598 1.633pF
3
1 2
START 2.3GHz [ 10.00 dBm] STOP 2.55GHz −502.3 2.325 2.35 2.375 2.4 2.425 2.45 2.475 2.5 2.525 2.55
−45
−40
−35
−30
−25
−20
−15
−10
−5 0
Frequency (GHz)
Log(|S11|) (dB)
1
2 3
4
1: 2.400 GHz −7.40 dB 2: 2.450 GHz −16.58 dB 3: 2.485 GHz −16.58 dB 4: 2.500 GHz −12.50 dB
Figure 10 : S11 measurements for the internal inverted-F antenna when no battery pack is present
Internal Antenna with Battery Pack
2004/11/25 Thr 14:49:13
CH2 S11 SMITH(R+jX) FS 1.000
MKR 3: 2.483 958 333GHz 57.265 7.168
Cor
3:2.483 958GHz 57.205 7.146 457.900pH 2:2.450 000GHz 34.763 -8.204 7.917pF 1:2.400 000GHz 38.610 -49.225 1.347pF
1 2
3
START 2.3GHz [ 10.00 dBm] STOP 2.55GHz −502.3 2.325 2.35 2.375 2.4 2.425 2.45 2.475 2.5 2.525 2.55
−45
−40
−35
−30
−25
−20
−15
−10
−5 0
Frequency (GHz)
Log(|S11|) (dB)
1
2
3 4
1: 2.400 GHz −5.10 dB 2: 2.450 GHz −13.27 dB 3: 2.485 GHz −20.92 dB 4: 2.500 GHz −12.24 dB
Figure 11 : S11 measurements for the internal inverted-F antenna with battery pack underneath
Low Power Wireless Sensor Module
Radiation Pattern
Figure 12 : Radiated pattern of the Inverted-F antenna with horizontal mounting (from Chipcon AS)
Figure 13 : Radiated pattern of the Inverted-F antenna with vertical mounting (from Chipcon AS)