1. INTELLIGENT HELMET FOR COAL
MINERS
Department of Electrical Engineering
NEHRU COLLEGE OF ENGINEERING AND RESEARCH CENTRE
Pampady, Thiruvilwamala, Thrissur โ 680 588, Kerala, INDIA
Group members Guided by
AKHIL KRISHNAN V (NCAMEEE011) Mr. ANOOP KUMAR MV
ARUN P S (NCAMEEE026) Asst. Professor,EEE Dept.
D YATHISHAN (NCAMEEE036)
JOMICE THOMAS (NCAMEEE051)
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2. OBJECTIVE
๏ด To provide greater security in coal mining, we are introducing a
new technology that can be incorporated in the helmet used by coal
miners which will act as โ INTELLIGENT HELMET FOR
COAL MINERSโ.
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3. METHODOLOGY
๏ด Our project consists of two sections transmitting end and
receiving end. The receiving end consists of power supply unit.
๏ด Our group had completed the power supply unit which consists
of a bridge rectifier.
๏ด Output of the bridge rectifier is fed to regulators 7805 and 7809
which gives an output voltage of 5V and 9V.
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4. ๏ด The 5V supply is fed to run the LCD display and the
ZIGBEE module. The 9V supply is used to charge the battery
which runs the PIC and ZIGBEE transmitter.
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6. COMPONENTS
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COMPONENTS DESCRIPTION SPECIFICATION
MICRO CONTROLLER PIC16F887 40 PIN, 220uA (2.0V, 4MHz),
11uA (2.0 V, 32 KHz) 50nA
ALPHA NUMERIC LCD DISPLAY 2 X 16 VIEWING AREA
GAS SENSORS CO2 AND METHANE
SENSORS
MQ6
TEMPERATURE SENSOR CALIBRATED IN CELSIUS LM35
HUMIDITY SENSOR SENSES THE HUMIDITY 1 V, 0.22 MW, 0-60 ฬC
BUZZERS
7. COMPONENTS DESCRIPTION
๏ด The PIC16F887
It is one of the latest products from Microchip. It features all the components which
modern microcontrollers normally have. For its low price, wide range of application,
high quality and easy availability, it is an ideal solution in applications such as: the
control of different processes in industry, machine control devices, measurement of
different values etc. Some of its main features are listed below.
โข RISC architecture
o Only 35 instructions to learn
o All single-cycle instructions except branches
โข Operating frequency 0-20 MHz
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8. โข Precision internal oscillator
o Factory calibrated
o Software selectable frequency of 4MHz
โข Power supply voltage 2.0-5.5V
o Consumption: 220uA (2.0V, 4MHz), 11uA (2.0 V, 32 KHz) 50nA (stand-by
mode)
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9. โข 33 input/output pins
o High current source/sink for direct LED drive
o software and individually programmable pull-up resistor
o Interrupt-on-Change pin
โข 8K ROM memory in FLASH technology
o Chip can be reprogrammed up to 100 times
โข In-Circuit Serial Programming Option
o Chip can be programmed even embedded in the target device
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10. โข 256 bytes EEPROM memory
o Data can be written more than 1000 times
โข 368 bytes RAM memory
โข A/D converter:
o 14-channels
o 10-bit resolution
โข 3 independent timers/counters
โข Watch-dog timer
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11. โข Analogue comparator module with
o Two analogue comparators
o Fixed voltage reference (0.6V)
o Programmable on-chip voltage reference
โข PWM output steering control
โข Enhanced USART module
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12. ๏ด 2X16 ALPHA NUMERIC LCD
The LCD display line consists of two lines, 16 characters per line that is interfaced
to the PIC16F887.The display contains two thermal byte-wide registers, one for
commands (instruction) (RS=0) and the second for characters (data) to be displayed
(RS=1).It also contains a user-programmed RAM area that can be programmed to
generate any desired character that can be formed using a dot matrix. To distinguish
between these two data, the hex command byte 80 will be used to signify that the
display RAM address 00h will be chosen port1is used to furnish the command and
ports 3.2 to 3.4 furnish register select and read/write levels
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13. ๏ด GAS SENSOR
Gas sensor is a device that detects the presence of gases like carbon
monoxide, methane and other toxic gases and if exceeds the threshold
limit produces an alarm through the buzzer. The common types of gas
sensor are:
๏ด Ionization gas sensor MQ6
๏ด Photoelectric gas sensor
Photoelectric gas sensors are faster in detecting smoldering fires.
Ionization gas sensors are better at detecting the flaming fires.
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14. ๏ด TEMPERATURE SENSORS
The LM35 series are precision integrated-circuit temperature sensors,
whose output voltage is linearly proportional to the Celsius
(centigrade) temperature. The LM35 thus has an advantage over linear
temperature sensors calibrated in Kelvin, as the user is not required to
subtract a large constant voltage from its output to obtain convenient
scaling. The LM35 does not require any external calibration of
trimming to provide typical accuracies of ยฑ1/40C at room temperature
and ยฑ3/40C over a full -55 to -150C temperature range.
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15. ๏ด HUMIDITY SENSOR
Humidity sensors are gaining more significance in diverse areas of
measurement and controlling technology. The amount of the
water present in the air is nothing but the humidity. Humidity
sensor used is SHT21.
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16. ๏ด BUZZER
It is a signaling device, usually electronic, typically used in
automobiles. It mostly consists of a number of switches or sensors
connected to a control unit. These buzzers are available in
lightweight compact sizes ranging from the smallest diameter of
12mm to large Piezo electric sounders. Today piezoelectric sound
components are used in home appliances, audio equipment etc.
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18. ๏ด TRANSFORMER: The transformer will step down the power
supply voltage (0-230V) to (0-12V) .
๏ด BRIDGE RECTIFIER: It perform the ac to dc conversion.
๏ด FILTER:A RC filter is used to eliminate the ripples present in
the output.
๏ด IC 7812:At the output of IC 7812 we get a regulated 12v DC.
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20. ๏ด POWER SUPPLY CIRCUIT DIAGRAM
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โข Each one of the blocks has its own special functions regarding the whole system.
โข The ac voltage, typically 230V rms, is connected to a transformer, which steps that ac
voltage down to the level of the desired dc output.
21. ๏ด A diode rectifier then provides a full-wave rectified voltage that
is initially filtered by a simple capacitor filter to produce a dc
voltage.
๏ด This resulting dc voltage usually has some ripple or ac voltage
variation.
๏ด IC 7812 voltage regulator circuit removes the ripples and also
remains the same dc value even if the input dc voltage varies, or
the load connected to the output dc voltage changes.
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