The document describes an intelligent helmet being developed for coal miners that aims to provide greater safety. It contains sensors like gas, temperature, and humidity sensors as well as a microcontroller and LCD display. The transmitting end will contain these sensors and microcontroller and the receiving end will monitor the data received. It provides block diagrams of the system components and circuit diagrams for the power supply and microcontroller connections. The power supply converts mains AC to regulated 5V and 9V DC required for components using a transformer, rectifier, and voltage regulators.

1. INTELLIGENT HELMET FOR COAL
MINERS
Department of Electrical Engineering
NEHRU COLLEGE OF ENGINEERING AND RESEARCH CENTRE
Pampady, Thiruvilwamala, Thrissur – 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
 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 “ INTELLIGENT HELMET FOR
COAL MINERS”.
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3. METHODOLOGY
 Our project consists of two sections transmitting end and
receiving end. The receiving end consists of power supply unit.
 Our group had completed the power supply unit which consists
of a bridge rectifier.
 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.  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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5. BLOCK DIAGRAM
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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 ̊C
BUZZERS

7. COMPONENTS DESCRIPTION
 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.
• RISC architecture
o Only 35 instructions to learn
o All single-cycle instructions except branches
• Operating frequency 0-20 MHz
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8. • Precision internal oscillator
o Factory calibrated
o Software selectable frequency of 4MHz
• 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. • 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
• 8K ROM memory in FLASH technology
o Chip can be reprogrammed up to 100 times
• In-Circuit Serial Programming Option
o Chip can be programmed even embedded in the target device
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10. • 256 bytes EEPROM memory
o Data can be written more than 1000 times
• 368 bytes RAM memory
• A/D converter:
o 14-channels
o 10-bit resolution
• 3 independent timers/counters
• Watch-dog timer
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11. • Analogue comparator module with
o Two analogue comparators
o Fixed voltage reference (0.6V)
o Programmable on-chip voltage reference
• PWM output steering control
• Enhanced USART module
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12.  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.  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:
 Ionization gas sensor MQ6
 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.  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 ±1/40C at room temperature
and ±3/40C over a full -55 to -150C temperature range.
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15.  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.  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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17. POWER SUPPLY BLOCK DIAGRAM
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18.  TRANSFORMER: The transformer will step down the power
supply voltage (0-230V) to (0-12V) .
 BRIDGE RECTIFIER: It perform the ac to dc conversion.
 FILTER:A RC filter is used to eliminate the ripples present in
the output.
 IC 7812:At the output of IC 7812 we get a regulated 12v DC.
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19. CIRCUIT DIAGRAM
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RA0/AN0
2
RA1/AN1
3
RA2/AN2/VREF-/CVREF
4
RA4/T0CKI/C1OUT
6
RA5/AN4/SS/C2OUT
7
RE0/AN5/RD
8
RE1/AN6/WR
9
RE2/AN7/CS
10
OSC1/CLKIN
13
OSC2/CLKOUT
14
RC1/T1OSI/CCP2
16
RC2/CCP1
17
RC3/SCK/SCL
18
RD0/PSP0
19
RD1/PSP1
20
RB7/PGD
40
RB6/PGC
39
RB5
38
RB4
37
RB3/PGM
36
RB2
35
RB1
34
RB0/INT
33
RD7/PSP7
30
RD6/PSP6
29
RD5/PSP5
28
RD4/PSP4
27
RD3/PSP3
22
RD2/PSP2
21
RC7/RX/DT
26
RC6/TX/CK
25
RC5/SDO
24
RC4/SDI/SDA
23
RA3/AN3/VREF+
5
RC0/T1OSO/T1CKI
15
MCLR/Vpp/THV
1
U2
PIC16F877A
D7
14
D6
13
D5
12
D4
11
D3
10
D2
9
D1
8
D0
7
E
6
RW
5
RS
4
VSS
1
VDD
2
VEE
3
LCD2
LM016L
X1
CRYSTAL
C1
22pF
C2
22pF
RA0/AN0
2
RA1/AN1
3
RA2/AN2/VREF-/CVREF
4
RA4/T0CKI/C1OUT
6
RA5/AN4/SS/C2OUT
7
RE0/AN5/RD
8
RE1/AN6/WR
9
RE2/AN7/CS
10
OSC1/CLKIN
13
OSC2/CLKOUT
14
RC1/T1OSI/CCP2
16
RC2/CCP1
17
RC3/SCK/SCL
18
RD0/PSP0
19
RD1/PSP1
20
RB7/PGD
40
RB6/PGC
39
RB5
38
RB4
37
RB3/PGM
36
RB2
35
RB1
34
RB0/INT
33
RD7/PSP7
30
RD6/PSP6
29
RD5/PSP5
28
RD4/PSP4
27
RD3/PSP3
22
RD2/PSP2
21
RC7/RX/DT
26
RC6/TX/CK
25
RC5/SDO
24
RC4/SDI/SDA
23
RA3/AN3/VREF+
5
RC0/T1OSO/T1CKI
15
MCLR/Vpp/THV
1
U2
PIC16F877A
D7
14
D6
13
D5
12
D4
11
D3
10
D2
9
D1
8
D0
7
E
6
RW
5
RS
4
VSS
1
VDD
2
VEE
3
LCD2
LM016L
5 v
R1
10k
RESET
X1
4 MHz
C1
22pF
C2
22pF
VI
1
VO
3
GND
2
U2
7805
5vDC
50%
TEMPERATURESENSOR
10k
HUMIDITY SENSOR
R2
10k
R3
10k
R4
10k
R5
10k
R6
10k
R7
10k
R8
10k
R9
10k
R10
10k
R11
10k
BATTERY
GAS SENSOR
RXD
RTS
TXD
CTS
ZIGBEE

20.  POWER SUPPLY CIRCUIT DIAGRAM
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• Each one of the blocks has its own special functions regarding the whole system.
• 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.  A diode rectifier then provides a full-wave rectified voltage that
is initially filtered by a simple capacitor filter to produce a dc
voltage.
 This resulting dc voltage usually has some ripple or ac voltage
variation.
 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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22. FLOW CHART
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23. Department Of Electrical Engineering 23

24. THANK YOU!!!!
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