Embed Size (px)
Citation preview
SensMote Board PRO
Technical Guide
SensMote Pro
Page 2 of 22
1. Features
The SensMote PRO is composed by different
components embedded in the board, each one with its
functionality and own characteristics, also are available
module boards for specific and general purposes. This
provides to SensMote high versatility that allows
integrate it in a lot of applications.
Some of the general characteristics of the components
integrated in the SensMote Pro are:
- Power supply (MCP1703 & SPX3819): SensMote
has two regulators (MAIN & SECONDARY), the first
is always ON and supply to the main components
of the board, and the second can be enabled and
disabled , this feature provides to SensMote works
with different low power consumption modes,
saving energy and extending the useful life of the
battery.
- AVR 8-bit Microcontroller (ATmega1284P): is the
brain of SensMote PRO, it has digital and analog
(10-bit ADC) I/O signals that are available in the
connectors, it also has different data buses (I2C,
SPI and USART) to connect different peripherals of
the board and they are available in the interface
connectors. The ATmega1284P has an Internal
EEPROM memory of 4K Bytes, 128K Bytes Flash
memory and 16K Bytes SRAM. More specifications
can be found in proprietary datasheet of
ATmega1284P.
- Real Time Clock (DS3231SN): is one of the most
accurate clocks on the market because it has an
internal compensation mechanism for the
oscillation variations produced in the quartz
crystal by changes in temperature. It is controlled
by I2C bus and has a pin connected to the
microcontroller (D15) for the interrupt functions.
- LED Dimmer (PCA9533): SensMote includes a
visual output interface driven by the I2C bus,
dimmer can drive four independent LEDs with four
independent operation modes: On, Off, Fast blink
and Slow blink.
- EEPROM Memory (24LC512): external memory of
512K bits (128K Byes) of storage size. The
communication is over I2C protocol.
- Flash Memory (W25Q128FVSIG): external
memory of 128M bits (16.384K Bytes) of storage
size. Communications between microcontroller
and flash are done through the SPI bus.
- MicroSD socket: SensMote uses the FAT file
system and can support cards up to 32G Bytes.
Communication between microcontroller and
microSD are done through the SPI bus.
- Multiplexor (ADG888YRUZ): is used to change the
way of USART bus between the different
interfaces of the SensMote. This is controlled by
digital pins to select the desired mode (D18 and
D19).
Applications:
- Network hub.
- Communication gateway.
- Data acquisition (with the different
sensor modules).
SensMote Pro
Page 3 of 22
Index 1. Features ............................................................................................................................................................................ 2
2. General Description .......................................................................................................................................................... 4
3. Specifications .................................................................................................................................................................... 5
4. Electrical Characteristics ................................................................................................................................................... 5
5. Block Diagram ................................................................................................................................................................... 5
6. Input/Output .................................................................................................................................................................... 7
7. Operation .......................................................................................................................................................................... 9
8. Power ................................................................................................................................................................................ 9
9. Digital Input/Output ....................................................................................................................................................... 13
10. Analog Input .............................................................................................................................................................. 13
11. Communications Ports .............................................................................................................................................. 14
12. Peripherals ................................................................................................................................................................. 16
13. Interruptions .............................................................................................................................................................. 18
14. Watchdog .................................................................................................................................................................. 19
15. Low-Power Operation................................................................................................................................................ 19
16. Dimensions ................................................................................................................................................................ 20
17. Use of equipment characteristics .............................................................................................................................. 21
18. Disposal and recycling ............................................................................................................................................... 21
19. Document ChangeLog................................................................................................................................................ 22
SensMote Pro
Page 4 of 22
2. General Description
The SensMote hardware architecture is based on the Atmel ATmega1284P microcontroller, and has a modular
architecture.
SensMote has Communication and Sensors modules to be added. These modules can be changed and expanded
according to the needs of each application where it is installed.
Some modules available for integration in SensMote are:
- ZigBee/802.15.4/XBee modules (2.4GHz, 868MHz, 915MHz)
- LoRa Module (433/868/915MHz)
- GSM/GPRS Module (850MHz/900MHz/1800MHz/1900MHz)
- WiFi Module
- Sigfox
- Sensor Modules (Sensor Boards)
SensMote Pro
Page 5 of 22
3. Specifications
The general specifications of the SensMote PRO and its embedded components are:
Weight 30 gr
Dimensions 70 x 90 x 1.6 mm
Temperature Range -10°C to +65°C
Embedded microcontroller ATmega1284P
Microcontroller frequency crystal 16 Mhz
Real Time Clock ~2 ppm accuracy
EEPROM Memory 512K bits (128K Byes)
FLASH Memory 128M bits (16.384K Bytes)
SD Memory Card socket up to 32G Bytes maximum size
Digital I/O pins 8 (of which 1 is in expansion connector)
Analog pins 7 (of which 1 is in expansion connector)
4. Electrical Characteristics
The general specifications about the input supply voltage (PWRIN pin) and the voltage and current provided by output
pins (I/O digital and analog pins) and supply power pins (SECONDARY 3.3V pin) in SensMote PRO are:
Minimum operating supply voltage (PWRIN pin) 3.6 V
Maximum operating supply voltage (PWRIN pin) 15 V
Voltage range at any output pin -0.5 V +3.8 V
Maximum current from any output pin 40 mA
Maximum current from power supply 3.3V 250 mA
5. Block Diagram
These block diagrams show the relationship between the different components of the SensMote PRO, signal and power
connections.
SensMote Pro
Page 6 of 22
5.1. Data Signals
5.2. Power Signals
SensMote Pro
Page 7 of 22
6. Input/Output
SensMote PRO can communicate with other external devices through the use of different input/output ports.
Pin out description is shown in the image and tables.
SensMote Pro
Page 8 of 22
FTDI interface
PIN Description
1 DTR *
2 UART0_MUX0_TX
3 UART0_MUX0_RX
4 MAIN +3V3
5 N/C
6 GND
*(marked by white square in the silkscreen of the board)
ICSP interface
Description PIN PIN Description
MISO* 1 2 MAIN+3V3
SCK 3 4 MOSI
RESET 5 6 GND
*(marked by white square in the silkscreen of the board)
Module Communications Interface (COMM connector)
Description PIN PIN Description
PWR_IN 1 2 PWR_IN
SECONDARY +3.3V 3 4 ANALOG2
DIGITAL2_INT2 5 6 ANALOG1
DIGITAL1 7 8 ANALOG0
DIGITAL5_MOSI 9 10 DIGITAL0
DIGITAL7_SCK 11 12 DIGITAL6_MISO
DIGITAL17_SDA 13 14 DIGITAL16_SCL
DIGITAL22 15 16 DIGITAL23
UART0_MUX1_TX 17 18 UART0_MUX1_RX
GND 19 20 GND
Module Sensors Interface (SENS connector)
Description PIN PIN Description
PWR_IN 1 2 PWR_IN
SECONDARY +3.3V 3 4 ANALOG5
DIGITAL2_INT2 5 6 ANALOG4
DIGITAL13 7 8 ANALOG3
DIGITAL5_MOSI 9 10 DIGITAL12
DIGITAL7_SCK 11 12 DIGITAL6_MISO
DIGITAL17_SDA 13 14 DIGITAL16_SCL
UART1_MUX0_TX 15 16 UART1_MUX0_RX
UART1_MUX1_TX 17 18 UART1_MUX1_RX
GND 19 20 GND
Expansion Interface
PIN Description
1 GND
2 A6
3 SECONDARY +3.3V
4 D3
5 SCL
6 SDA*
*(marked by white square in the silkscreen)
SensMote Pro
Page 9 of 22
LED Interface
This interface is designed to have a programmable operation visual feedback without the need of any extra connection,
thanks to its programmable dimmer (PCA9533). It is driven by the I2C bus and powered by the SECONDARY 3.3V line. It
has four LEDs named A, B, C and D and they can have four independent states: ON, OFF, Fast Blink, Slow Blink. These
features provide to the board a large number of possible codes for operation visual feedback or fault notification.
7. Operation
This processing unit starts executing the bootloader binary, which is responsible for loading into the memory the
compiled programs and libraries previously stored in the microcontroller flash memory, so the main program that has
been created can finally begin running.
When SensMote is connected and starts the bootloader, there is a waiting time before beginning the first instruction, this
time is used to start loading new compiled programs updates. If a new program is received from the FTDI during this time,
it will be loaded into the flash memory substituting existing programs. Otherwise, if a new program is not received, the
last program stored in the memory will start running.
The structure of the codes is divided into 2 basic parts: setup and loop. Both parts of the code have sequential behaviour,
executing instructions in the set order. The setup is the first part of the code, which is only run once when the code is
initialized. In this part it is recommended to include the initialization of the modules which are going to be used, as well as
the part of the code which is only important when SensMote is started. The part named loop runs continuously, forming
an infinite loop.
All information about their programming and operation can be found in the document: SensMote Pro Programming
Guide.
8. Power
The board can operate with an external DC power supply of 3.6 volts to 15 volts maximum value, if not exist a restriction
by a connected module, this range could change if the supply specifications of the other modules connected to the
SensMote restring this voltage levels.
SensMote Pro
Page 10 of 22
8.1. Power supply sources
SensMote can be powered with primary batteries, but it has different modules to supply the SensMote through an AC
plug (SensMote UPS AC) or through a solar panel (UPS DC), both with a battery backup.
Battery
The user can supply energy to the board through primary or secondary batteries. A correct wired connection between
these is required for ensure the correct and secure operation, the two types of battery used to power SensMote are:
- Battery not rechargeable.
- Battery rechargeable.
Warning:
DO NOT TRY TO RECHARGE THE NON-RECHARGEABLE BATTERY. IT MAY EXPLODE AND CAUSE INJURIES
AND DESTROY THE EQUIPMENT. DO NOT CONNECT EITHER UNDER ANY CIRCUMSTANCE THE UPS DC OR UPS AC TO A NON-RECHARGEABLE BATTERY AS IT MAY EXPLODE AND CAUSE INJURIES AND DESTROY
THE EQUIPMENT.
Solar Panel Module
The user has a specific module to supply energy to the SensMote through solar cells, this module is named SensMote UPS
DC. It has a backup-battery for the energy store. Also the module can be assembled with SensMote LITE or PRO with
clamping screws. There is a connector to make the wired connection between the SensMote LITE or PRO and the
SensMote UPS DC, and a second screw connector of SensMote UPS DC allows connect solar panel with a voltage range of
10 to 18V.
AC to DC power supply with Backup-Battery Module
The user can use the module SensMote UPS AC for supply the SensMote PRO or LITE. This module can be connected at AC
power point (input range: 90V - 264V AC), it has a Backup-Battery in board which is charged by the AC to DC power
supply. Also the module can be assembled with SensMote LITE or PRO with clamping screws. Module has a connector to
make the wired connection with the SensMote LITE or PRO, a second connector of SensMote UPS AC allows connect a AC
source with a voltage range of 90V - 264V AC.
SensMote Pro
Page 11 of 22
8.2. Interfaces power pins
Power supply connector
The power supply connector (P/N: XHP-2, manufacturer JST) has two pins to connect the positive (PWRIN) and negative
(GND) of the power supply.
Modules Interfaces
The module connectors (SENS and COMM connectors) have many signal and supply connections that are shown at the
image.
The main supply connections are:
PWR_IN: Normally this pin is used to power modules. But occasionally it can be used for input voltage to the SensMote
when it's using power module to supply the SensMote.
SECONDARY +3.3V: this pin is connected to 3.3V secondary regulator circuit of SensMote PRO (maximum output current
250 mA) and normally is used to provide an additional supply to other modules, because it can be controlled with an
enable signal by the microcontroller.
Expansion Interface
The expansion connector has many signal and supply connections that are shown in the image.
COMM SENS
SensMote Pro
Page 12 of 22
The main supply connections are:
SECONDARY +3.3V: this pin is connected to 3.3V secondary regulator circuit of SensMote PRO (maximum output current
250 mA) and normally is used to provide an additional supply to other modules, because it can be controlled with an
enable signal by the microcontroller.
FTDI Interface
The FTDI interface is used for programming and debugging. It uses the UART0_MUX0 signals and must be selected in the
multiplexer to be used.
The main supply connections are:
MAIN +3V3: This pin is connected to the MAIN 3.3V regulator circuit of the board. Extreme caution when powering
board through this pin, because differences on voltage levels (between SensMote Main regulator circuit and FTDI
device) can damage components. If you are not sure that both operate at the same voltage, for safety, it is
recommended only two options for programming the SensMote:
- If the SensMote is powered through the FTDI, remove the external power supply.
- If the energy to the board is supplied through the Power supply connector with an external power supply, not connect
MAIN 3.3V pin to FTDI interface.
ICSP Interface
In Circuit Serial Programming is the interface to program the microcontroller from a programmer without needing a
bootloader.
MAIN+3V3: This pin is connected to 3.3V pin of main regulator. Extreme caution when powering board through this pin,
because differences on voltage levels (between SensMote Main regulator circuit and ICSP programmer device) can
SensMote Pro
Page 13 of 22
damage components. If you are not sure that both operate at the same voltage, for safety, it is recommended only two
options for programming the SensMote:
- If the SensMote is powered through the ICSP, remove the external power supply.
- If the energy to the board is supplied through the Power supply connector with an external power supply, not connect
MAIN 3.3V pin to ICSP interface.
9. Digital Input/Output
SensMote has 8 accessible digital inputs (7 in SENS & COMM connector and 1 in expansion connector). Each input is
directly connected to the microcontroller. The digital ports are bi-directional I/O ports with optional internal pull-ups. All
I/O pins have protection diodes to both VCC and Ground.
SensMote digital pins can be configured as input or output depending on the needs for the application.
The voltage values corresponding to the different digital values for Vcc = 3.3V, would be:
Symbol Parameter Min. Typ. Max. Units
VIL Input low voltage (0 logic) -0.5 0 0.3Vcc V
VIH Input high voltage (1 logic) 0.6Vcc Vcc Vcc + 0.5 V
If some pins are unused, it is recommended to ensure that these pins have a defined level for ensure the correct
operation of SensMote.
10. Analog Input
SensMote has 7 accessible analog inputs (6 in SENS & COMM connector and 1 in expansion connector). Each input is
directly connected to the microcontroller. The microcontroller uses a 10 bit successive approximation analog to digital
converter (ADC). The reference voltage value for the inputs is 0V (GND). The maximum value of input voltage is 3.3V
which corresponds with the microcontroller’s general supply voltage (Microcontroller has selectable option for 2.56V or
1.1V ADC Reference Voltage). The obtained value from these inputs will be an integer number between 0 and 1023, 0
corresponds to 0V and 1023 to 3.3V.
Symbol Parameter Min. Typ. Max. Units
Resolution 10 Bits
Conversion Time 13 260 us
AVCC Analog Supply Voltage Vcc - 0.3 Vcc + 0.3 V
VIN Input Voltage GND VREF V
VINT1 Internal Voltage Reference 1.0 1.1 1.2 V
VINT2 Internal Voltage Reference 2.33 2.56 2.79 V
The Analog inputs can be used for capture values from different analogical systems to be monitored (Temperature,
Pressure, etc.). The analog pins can be used identically to the digital pins, using the aliases A0 (for analog input 0), A1, etc.
The ATmega1284P datasheet also cautions against switching analog pins in close temporal proximity to making A/D
readings (analogRead) on other analog pins. This can cause electrical noise and introduce jitter in the analog system. It
may be desirable, after manipulating analog pins (in digital mode), to add a short delay before using analogRead() to read
other analog pins.
Note: For more information of ADC converter features and how to use, please see ATmega1284p datasheet and
SensMote Development API documents.
SensMote Pro
Page 14 of 22
11. Communications Ports
The SensMote is mainly a Communication board. For this reason the connector has several communication protocols,
making the board versatile for communications.
USART Ports
The Universal Synchronous and Asynchronous serial Receiver and Transmitter (USART), communications are conducted
through two wires (RX and TX).
There are two USARTs in SensMote USART0 and USART1. Used to receive (RX) and transmit (TX) TTL serial data.
UART0 is connected to FTDI interface (USB adaptors are used to convert USB data to standard serial port data TTL) and to
module socket.
UART1 is connected to module socket Interface, for communication with other module boards.
The position management of this bus is realized by the multiplexor (MUX0 and MUX1 mode, read 12.4.Multiplexor
section of this document).
Note: Caution, connect the device Vcc pin and external power supply to SensMote simultaneously can damage any
component if the voltage levels are different, for more information read 8.2. Interface power pins section of this
document.
SPI Port
The Serial Peripheral Interface (SPI) allows high-speed synchronous data transfer between the ATmega1284p and
peripheral devices. ATmega1284p of SensMote is configured as a Master and other devices connected to SPI will be
configured as slaves.
The SPI port in the SensMote Boards is used for communication with:
- Flash Memory, to the management of stored data.
- MicroSD, to the management of stored data.
The SPI port is also available in the socket Module Interface, to give the board the capabilities to control devices placed
on other boards connected through the connector.
Finally, the SPI port is also available in ICSP (In Circuit Serial Programming) Interface, to program the microcontroller.
Follow these recommendations using an ICSP Programmer:
Caution, the logic levels for MISO, MOSI and SCK, as well as ICSP Programmer supply voltage pin, must be 3.3V, if you
do not follow the recommendations components can be damaged (Flash memory pins does not support 5V levels).
SensMote Pro
Page 15 of 22
Note: Caution, voltage levels for ICSP Programmer must be 3.3V, for more information read 8.2. Interface power pins
section of this document.
I2C Port
I2C is a 2 wire serial interface protocol that allows interconnect up to 128 different devices (7-bits slave addresses space),
using only two bidirectional bus lines, one for clock (SCL) and one for data (SDA), also it allows up to 400kHz Data Transfer
Speed. The only external hardware needed is a single pull-up resistor for each wire of 4.7kohms (built in board). All
devices connected have individual and programmable address.
The I2C communication bus is used in board to communications with RTC and Led Dimmer.
Also other modules can be connected to the bus through follow SensMote interface:
- Module Interface: For communications with SensMote module boards.
- Expansion Interface: For communications with external devices.
All devices are connected in parallel (without pull-up resistance, it is built in board), and in all cases, the microcontroller
acts as master while the other devices connected to the bus are slaves. Bus level voltage is 3.3V for 1 logic and 0V for 0
logic .
SensMote Pro
Page 16 of 22
12. Peripherals
12.1. Real Time Clock
SensMote has a built in Real Time Clock (RTC); it is the DS3231SN of Maxim. RTC keeps SensMote informed of the time.
Counts Seconds, Minutes, Hours, Date of the Month, Month, Day of the Week, and Year, with Leap-Year Compensation
Valid Up to 2100.
The DS3231SN is one of the most accurate clocks on the market because of its internal compensation mechanism for the
oscillation variations produced in the quartz crystal by changes in temperature (Temperature Compensated Crystal
Oscillator – TCXO). Thanks to the data received by the RTC’s internal temperature sensor.
- Operating Temperature Ranges: -40°C to +85°C
- Accuracy ±2ppm from 0°C to +40°C (variation of 0.16s per day (1min/year))
- Accuracy ±3.5ppm from -40°C to +85°C (±2 minutes per year accuracy)
- Digital Temp Sensor: ±3°C Accuracy (value of sensor can be accessed through the I2C bus. Temperature is
represented as a 10-bit code with a resolution of 0.25°C, with a range of -40ºC to +85ºC ).
Note: the RTC’s internal temperature sensor is only meant for the time derive compensation, but not for common air
temperature sensing (we advise our Sensor Boards for that).
All RTC programming and control is done through the I2C bus.
Alarms can be programmed in the RTC specifying day/hour/minute/second. That allows total control about when the
SensMote wakes up to capture sensor values and perform actions programmed on it. This allows SensMote to be in the
saving energy modes and makes it wake up just at the required moment. As well as relative alarms, periodic alarms can
be programmed by giving a time measurement, so that SensMote reprograms its alarm automatically each time one is
triggered. So the RTC is responsible for waking up SensMote from the energy saving modes by alarms programmed in
source code.
This allows SensMote to be programmed to perform time-related actions such as:
“Sleep for 1h 20 min and 15sec, then wake up and perform the following action”
Or even programs to perform actions at absolute intervals:
“Wake on the 5th of each month at 00:20 and perform the following action”
The RTC is powered by SECONDARY 3.3V regulator (in Vcc pin of RTC) and have a Battery-Backup Input for Continuous
Timekeeping (in Vbat pin of RTC).
Thereby, when microcontroller is in Low Power Operation (SECONDARY regulator 3.3V is off) the RTC is powered by
Battery-Backup giving to the board low power features.
Battery-Backup is a 0.22F bypass supercapacitor, it is charged automatically from the main power supply (MAIN 3.3V).
The maximum charging current is rated at 16mA limited by a serial resistor and a diode avoiding the super capacitor
powering the board. The time for fully charging is about ten minutes and it will last for at least 10 hours.
12.2. LED dimmer
SensMote includes a visual output interface driven by the I2C bus and powered by the SECONDARY 3.3V circuit.
The dimmer can drive four independent LEDs with four independent operation modes: On, Off, Fast blink and Slow blink.
The blink rates are fully programmable between 0.591 Hz and 152 Hz (1.69 second and 6.58 milliseconds) with 256
brightness steps.
SensMote Pro
Page 17 of 22
The four drivers are open drain outputs to directly drive LEDs (each LED has a consumption of 3mA).
12.3. Data Storage
SensMote includes different ways to storage data with the purpose of storage data until they are exported.
EEPROM Memory
SensMote has a built in EEPROM memory (24LC512) with 512K bits (128 K Bytes) of storage size. The communication is
over I2C protocol.
The memory is expandable for up to eight devices thanks to its pin selectable address and its 2-Wire Serial interface which
is compatible with the I2C protocol. The page write time is 5ms max with self-timed Erase/Write Cycle with more than a
million erase/write cycles and it has a 128 byte page write buffer.
EEPROM memory is powered from the SECONDARY 3.3V circuit which can be switched off for a lower power consumption
of the board.
FLASH Memory
Flash memory is powered from the SECONDARY 3V3 circuit which can be switched off for a lower power consumption of
the board.
SensMote has a built in FLASH memory (W25Q128FV) with 128 Mbits (16.384K Bytes) of storage size and all
communication between microcontroller and flash is done through the SPI bus.
- This memory has 4KB erasable sectors & 32KB/64KB erasable blocks in 65.536 pages of 256 bytes with a page program
time of 0.7 ms (typ.).
- The IC can perform a continuous read with 8/16/32/64 byte Wrap with a clock operation up to 104 MHz.
- Minimum and maximum operational voltage values are 2.7 to 3.6V.
- Consumption of 4mA when reading and 1µA in power down mode.
- Operating Temperature Ranges: -40° to +85°C
- Lock-Down and OTP (Over Temperature Protection)
- The internal registers have included a program/erase, suspend/resume, suspend status bit and a factory-programed
unique ID.
SD Card Memory
SensMote has a built in socket for storage data in micro SD (Secure Digital) cards at the top left of the board. These cards
are used specifically to reduce board space to a minimum with a big size of storage.
SensMote uses the FAT file system and can support cards up to 32GB. The information that SensMote stores in files on
the SD can be accessed from different operating systems such as Linux, Windows or Mac-OS. There are many SD card
models; any of them has defective blocks, which are ignored when using the SD library.
SensMote Pro
Page 18 of 22
12.4. Multiplexor
Sensmote has a multiplexor (ADG888YRUZ) to management the two USART serial buses (USART0 and USART1).
The control is realized through the two digital pins of the microcontroller (D18 and D19), and provides two modes of bus
connections to interfaces.
- Mode 1 (MUX0): UART0 is connected to FTDI interface and UART1 is connected to SENS connector (right
header of the board).
- Mode 2 (MUX1): UART0 is connected to the COMM connector (left header of the board) and the UART1
is connected to the SENS connector (right header of the board).
13. Interruptions
Interruptions are signals received by the microcontroller which indicate it must stop the task that is doing to attend to an
event that has just happened. Interruption control frees the microcontroller from having to control sensors all the time. It
also makes the sensors warn SensMote when a determined value (threshold) is reached.
So it can be used for advertise the microcontroller when the program is run or for wake up the microcontroller when it is
in Sleep mode (saving energy mode).
SensMote is designed to work with 2 types of interruptions: Synchronous and asynchronous
Synchronous Interruptions
They are programmed by timers. They allow to program when we want them to be triggered. There are two types of
timer alarms: periodic and relative.
- Periodic Alarms are those to which we specify a particular moment in the future, for example: “Alarm programmed for
every fourth day of the month at 00:01 and 11 seconds”, they are controlled by the RTC.
- Relative alarms are programmed taking into account the current moment, eg: “Alarm programmed for 5 minutes and 10
seconds”, they are controlled through the RTC and the microcontroller’s internal Watchdog.
Asynchronous Interruptions
These are not programmed so it is not known when they will be triggered by external events. Types of external events:
- Sensors: SensMote can be programmed so that an alarm is triggered when a sensor reaches a certain threshold, or
detect to pulse sensors connected to pin change interrupt.
All interruptions, both synchronous and asynchronous can wake up SensMote.
There are two types of interrupts pins in SensMote:
- External interrupts: located in Interface module (D2_INT2)
- Pin Change Interrupt: located in Interface module and Expansion socket (All Digital and Analog pins, but there are only 4
interrupt vectors for all pins, one for each port, PCINT0_vect, PCINT1_vect, PCINT2_vect and PCINT3_vect).
SensMote Pro
Page 19 of 22
14. Watchdog
The Atmega1284 microcontroller has an internal Enhanced Watchdog Time (WDT). The WDT precisely counts the clock
cycles generated by a 128KHz oscillator. The WDT generates an interruption signal when the counter reaches the set
value. This interruption signal can be used to wake the microcontroller from the Sleep mode or to generate an internal
alarm when it is running ON the mode, which is very useful when developing programs with timed interruptions. The
WDT allows the microcontroller to wake up from a low consumption Sleep mode by generating an interruption. For this
reason, this clock is used as a time-based alarm associated with the microcontroller’s Sleep mode. This allows very precise
control of small time intervals: 16ms, 32ms, 64ms, 128ms, 256ms, 500ms, 1s, 2s, 4s, 8s. For intervals over 8s (Deep Sleep
mode) the RTC is used.
15. Low-Power Operation
Management Linear regulators in board
SensMote has two linear regulators of 3.3V in the board, thereby two separate power systems are available.
The first is always on (3.3V Main Regulator), and supplies power to the microcontroller.
The seconds can be disconnected (3.3V Secondary Regulator), it supplies power to the RTC (when it is off the Battery-
Backup powered RTC), Flash Memory, SECONDARY 3V3 pin of Expansion Interface and SECONDARY 3V3 pin of Module
Interface.
Management saving energy modes of microcontroller
Besides, the microcontroller can work in six sleep modes, each is configurable and there are several sub-modes with
different consumptions depending active parts of the microcontroller:
Idle Mode.
ADC Noise Reduction Mode.
Power-down Mode.
Power-save mode.
Standby mode.
Extended Standby Mode.
Next table shows different clocks and oscillators actives, and interruptions for wake up microcontroller in each mode.
SensMote Pro
Page 20 of 22
Therefore to simplify, let’s split the consumption of SensMote in 3 power mode operation:
- AWAKE: All are active (IC are are in standby mode, but no in run mode). Consumption in this state is
13.5mA.
- AWAKE & SECONDARY +3V3 OFF: Microcontroller is in run mode and the Secondary regulator is off, so
there aren’t consumption by the other IC. Consumption in this state is 11.5mA.
- SLEEP & SECONDARY +3V3 OFF: Microcontroller is in Sleep-Mode and the Secondary regulator is off, so
there isn’t consumption by the other IC. Consumption in this state is 40μA.
The main program is paused, the microcontroller passes to a latent state, from which it can be woken up by all
asynchronous interruptions in D2_INT2 pin produced by external events and by the synchronous interruption generated
by the Watchdog and the RTC.
16. Dimensions
Dimensions of the SensMote PRO are shown in the image.
SensMote Pro
Page 21 of 22
17. Use of equipment characteristics
Equipment to be located in an area of restricted access, where only expert appointed personnel can access and handle it.
The integration and configuration of extra modules, antennas and other accessories must also be carried out by expert
personnel.
It is the responsibility of the installer to find out about restrictions of use for frequency bands in each country and act in
accordance with the given regulations. ADC Infraestructuras y Sistemas S.L does not list the entire set of standards that
must be met for each country.
18. Disposal and recycling
In this section, the term “SensMote” encompasses both the SensMote device itself as well as its modules and sensor
boards.
When SensMote reaches the end of its useful life, it must be taken to an electronic equipment recycling point.
The equipment must be disposed of in a selective waste collection system, and not that for urban solid residue. Please
manage its disposal properly.
Your distributor will inform you about the most appropriate and environmentally friendly disposal process for the used
product and its packaging.
SensMote Pro
Page 22 of 22
19. Document ChangeLog
Version Date Author Description
1.0 02/10/2015 Manolo Gasch First version
1.1 10/11/2016 Jose Luis Romero
Any reproduction, in whole or in part, of this document or of one or several of its components, by whatsoever process, is
forbidden without the express authorization of the copyright owners.
