The document outlines a project focused on developing a prepaid energy meter using a PIC microcontroller, enabling the monitoring and controlling of energy consumption via a smart card system. This system aims to reduce power pilferage, streamline energy billing through automatic meter reading, and improve overall energy management for consumers and electricity providers. The project emphasizes the benefits of using prepaid meters, including customer flexibility, cost management, and energy conservation.

1. PREPAID ENERGY METER USING PIC
MICROCONTROLLER

2. INTRODUCTION
• The scope of the project work is to introduce advanced
technology in converting dc voltage in to ac voltage and
introducing prepaid energy metering concept.
• The energy meter used in this project work produces pulses
according to the load and this meter is converted as prepaid
energy meter using smart card, hence this meter can be
called smart energy meter.
• This kind of smart energy meters also can be installed at each
and every house, where the state electricity department
going to supply the conventional energy. Now a days energy
Measurement and electric energy pilferage detection has
become prime importance for the state electricity
department.

3. INTRODUCTION
• With the help of this project work lot of Manpower can be
reduced and power pilferage can be controlled.
• The overall system can be called as AMR (Automatic
Meter reading) system, the main advantage of AMR
system is that the consumed energy price can be
calculated and at the same time price (amount in
rupees) can be displayed automatically.
• Finally the simplest form of smart metering is a display meter,
which allows consumers to monitor consumption in money
terms rather than kWh.

4. Outlook
• Monitor Unit of Split Meter
LCD
Button
IC card
socket

5. CIRCUIT DIAGRAM
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
U1
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
LCD1
LM016L
RV1(2)
51%
RV1
1k
X1
CRYSTAL
C1
22p
C2
22p
R1(1) R1
10k
C3
10u
D1
LED-BIRG
D2
LED-BIRG
OUT IR
T1IN
11
R1OUT
12
T2IN
10
R2OUT
9
T1OUT
14
R1IN
13
T2OUT
7
R2IN
8
C2+
4
C2-
5
C1+
1
C1-
3
VS+
2
VS-
6
U2
MAX232
C4
1u
C5
1u
C6
1u
C7
1u
C7(-)
from RF reader
TO reader
A1
1
A2
2
A3
3
A4
4
A5
5
D6
6
D7
7
D8
9
D9
10
TE
14
DOUT
15
RS
11
CTC
12
RTC
13
U3
M145026
to RF transmitter

6. CIRCUIT DIAGRAM
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
U1
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
LCD1
LM016L
RV1(2)
51%
RV1
1k
X1
CRYSTAL
C1
22p
C2
22p
R1(1) R1
10k
C3
10u
FROM RF transmitter
A1
1
A2
2
A3
3
A4
4
A5
5
D6
15
D7
14
D8
13
D9
12
VT
11
R2/C2
10
C1
7
R1
6
DIN
9
U2
M145027

7. BLOCK DIAGRAM
PIC16F877A
CARD READER
UNIT
GSM
POWER SUPPLY
RF RECEIVER
LCD DISPLAY
LOAD

8. BLOCK DIAGRAM EXPLANATION
• In this system the user has to purchase an EEPROM based recharge card
and it should be inserted in the slot provided on prepaid energy meter kit.
After inserting the recharge card into the system, Then the system will be
loaded with specific units as per the recharge card value. A 16X2 LCD is
provided to read units available. Here the system is connected with three to
four loads. If the load increases in the system, current also increases and is
calculated by an ADC and its corresponding count is also calculated.
Whenever the count value reaches one thousand, 1unit is decremented
from EEPROM and these values are displayed on LCD.
• An EEPROM is provided on the board to store the updated recharge units
and energy meter pulse count. At every instant the count value and units
values are stored in EPROM so that the data will not be lost even in power
failure cases. When 1 unit is decremented from EEPROM the system will
give a beep sound. If recharge value below 10 units the GSM modem send
alert message to owner .When the recharged units become zero on power
consumption, the system shutdown all the loads connected to it by giving a
continuous beep sound.

9. Hardware Components
• Power supply[5v]
• PIC16F877A microcontroller
• GSM modem
• Current Transformer
• Voltage Transformer
• Max232 – serial communication

10. Power Supply Circuit
VDD
VDD
C7
0.1 uF
JP2
220 VAC
1
2
- +
D1
1
4
3
2
U2
7805
1
3
2
VIN
G
ND
VOUT
C6
100 uF
C5
470 uF
R4
220 ohm
D2
LED

11. Power Supply – Circuit Description
• The operation of power supply circuits built using
filters, rectifiers, and then voltage regulators. Starting
with an AC voltage, a steady DC voltage is obtained by
rectifying the AC voltage, Then filtering to a DC level,
and finally, regulating to obtain a desired fixed DC
voltage. The regulation is usually obtained from an IC
voltage regulator Unit, which takes a DC voltage and
provides a somewhat lower DC voltage, Which remains
the same even if the input DC voltage varies, or the
output Load connected to the DC voltage changes.

12. About Microcontroller
• PIC16F877A microcontroller is used for this
project
• It is 8-bit Microcontroller
• System is RISC Architecture
• It has Small set of Instruction set
• It has 35-Instructions only
• Compatibility: avail 28/40 Pin ICs

13. Microcontroller overview
• Operating Speed Max 20 MHz, Voltage-(2-
5.5)v
• Memory:
Flash Program 8Kx14 Words,
RAM 368 Bytes,
EEPROM Data Memory 256 Bytes
• Low power, High speed Flash/EEPROM
Technology

14. Features of Microcontroller
• It has 5 Ports for Internal and External usage
• It has on chip Timers. 3 Timers are avail
• It has in built Analog to Digital Converter
• In built Multiplexer availability for signal Selection
• It has serial as well as Parallel Communication
facilities
• In built Capture, Compare and Pulse width
modulation

15. UART pins inPIC16f877A
• The UART always transmits data on pin RC6/TX
• The UART always receives data on pin RC7/RX
• The RS-232 standard defines lots of other
signals other than TX and RX used for
handshaking.

16. Voltages
• The UART input/output uses 0V for logic 0
and 5V for logic 1.
• The RS-232 standard (and the COM port) use
+12V for logic 0 and –12V for logic 1.
• To convert between these voltages levels we
need an additional integrated circuit (such as
Maxim’s MAX232).

17. MAX232
VD D
R X
TX
T2O U T
R 2IN
U 1
MAX232
13
8
11
10
1
3
4
5
2
6
12
9
14
7
16
15
R 1IN
R 2IN
T1IN
T2IN
C +
C 1-
C 2+
C 2-
V
+
V-
R 1O U T
R 2O U T
T1O U T
T2O U T
V
C
C
G
N
D
C 1 10 uF
C 4
10 uF
C 3
10 uF
C 2
10 uF

18. GSM modem
• A GSM modem is a wireless modem that works with a
GSM wireless network.
• A wireless modem behaves like a dial-up modem. The
main difference between them is that a dial-up modem
sends and receives data through a fixed telephone line
while a wireless modem sends and receives data through
radio waves.
• A GSM modem can be an external device or a PC Card /
PCMCIA Card. Typically, an external GSM modem is
connected to a computer through a serial cable or a USB
cable.
• Like a GSM mobile phone, a GSM modem requires a SIM
card from a wireless carrier in order to operate.

19. AT COMMANDS
• computers use AT commands to control modems. Both GSM
modems and dial-up modems support a common set of
standard AT commands.
• GSM modems support an extended set of AT commands.

20. Operations
• Reading, writing and deleting SMS messages.
• Sending SMS messages.
• Monitoring the signal strength.
• Monitoring the charging status and charge
level of the battery.
• Reading, writing and searching phone book
entries.

21. GSM phone or modem supports SMS text mode
Check if your GSM phone or modem supports SMS
text mode
To check if your modem supports this text mode,
you can try the following command:
AT+CMGF=1 <ENTER>
If the modem responds with "OK" this mode is
supported.

22. Software Tools
• MPLAB IDE
• Hitech c compiler
• Win pic programmer
• ORCAD design

23. MPLAB IDE

24. Winpic800 Programmer

25. Prepaid meters advantages
• High accuracy over a wide current dynamic range
• Reliability and robustness
• Flexibility of design
• Automatic Meter Reading (AMR)
• More easily enable new functionalities
• Multi tariff billing
• Tamper proofing
• Prepayment meters
• Power out range detection
• Power factor detection
• Easily reconfiguration, upgrade
• Do not use gears that wear out or magnets that saturate with DC
current
• Do not require precision mechanics or have large tolerance variations
over temperature

26. • Pay before use
• Keep customers on supply
• Recover money owed (debt)
• Lower Overheads
• No bill production
• No bill distribution
• No need to chase payments
• No further actions such as disconnections
Why Prepayment – Energy
Supplier?

27. Why Prepayment – Energy
Supplier?
• Social Acceptability
• Customer responsible for
Disconnection
• Load and Demand Side Management
• Limit load
• Load based
• Time based

28. Why Prepayment – The Customer?
• >80% Mobile phones used in India are
prepaid
• Flexible Payment Solution
• Pay to suit your income status
• Daily, Weekly , Monthly
Budgeting
• Show true cost of consumption and money
Left
• Reduce consumption when income is tight– make money last
• Reduce waste – conserve energy

29. • No Bills
• No hidden surprises
• No having to find the money
• No billing errors
• No socially unacceptable
• disconnections
Why Prepayment – The Customer?

30. CONCLUSIONS
• Advanced electricity meters that generate consumption data enabling
customers to see when they are using energy, to manage that use more
efficiently
• To save money by adjusting energy use in response to price signals.
• To save money, the consumed energy corresponding price is displayed for the
consumer benefits.
• This project work has been taken up which serves the purpose of energy
monitoring and controlling by implementing prepaid system.
• It is hoped that this work helps the electrical engineers for better energy
management and its utility in the distribution system for economic liability of the
electrical companies.

31. THANK YOU