1. SUBMITTED BY EDGEFX TEAM
Real Time Clock Based Solar LED Street Light Automation Using RTC and I2C Protocol
SUBMITTED BY
EDGEFX TEAM

2. ABSTRACT
High Intensity Discharge lamps (HID) used for urban street light are based on principle of gas discharge
White Light Emitting Diode (LED) can replace the HID lamps where intensity control is possible by pulse width modulation

3. BLOCK DIAGRAM

4. HARD WARE EQUIPMENTS POWER SUPPLY BLOCK
MICROCONTROLLER (AT89S52/AT89C51)
LED
PWM
Matrix Keypad
RTC
BC547
1N4007
RESISTORS & CAPACITORS

6. EMBEDDED SYSTEMS Definition for :- EMBEDDED SYSTEMS
A combination of hardware and software which together
form a component of a larger machine.
An example of an embedded system is a microprocessor that
controls an automobile engine.
An embedded system is designed to run on its own without
human intervention, and may be required to respond to
events in real time.

7. EMBEDDED SYSTEMS

8. AT89S52 MICRO CONTROLLER Compatible with MCS®-51 Products
8K Bytes of In-System Programmable (ISP) Flash Memory
4.0V to 5.5V Operating Range
Crystal Frequency MHZ
Three-level Program Memory Lock
256 x 8-bit Internal RAM
32 Programmable I/O Lines
Three 16-bit Timer/Counters
Eight Interrupt Sources
Full Duplex UART Serial Channel
Watchdog Timer
AT89S52

9. PIN DIAGRAM OF AT89S52

10. PWM
The PWM switching frequency has to be much faster than what would affect the load, which is to say the device that uses the power.
The term duty cycle describes the proportion of on time to the regular interval or period of time;
a low duty cycle corresponds to low power, because the power is off for most of the time. Duty cycle is expressed in percent, 100% being fully on.

11. PWM APPLICATIONS Telecommunications Power delivery Voltage regulation
Audio effects and amplification.

12. Keypad
A keypad is a set of buttons arranged in a block or "pad" which usually bear digits, symbols and usually a complete set of alphabetical letters. If it mostly contains numbers then it can also be called a numeric keypad.
In order to detect which key is pressed from the matrix, the row lines are to be made low one by one and read the columns. Assume that if Row1 is made low, then read the columns.
If any of the key in row1 is pressed then correspondingly the column 1will give low that is if second key is pressed in Row1, then column2 will give low.

13. DS1307 RTC
RTC?
The RTC chip is a specialized chip that just keeps track of time
It runs on a battery and keeps time for you even when there is a power outage!
Using an RTC, you can keep track of long timelines, even if you reprogram your microcontroller or disconnect it from USB or a power plug.
The RTC we'll be using is the DS1307 . It's low cost, easy to solder, and can run for years on a very small coin cell.

14. 56 byte nonvolatile RAM for general data storage
FEATURES OF DS1307
Real time clock counts seconds, minutes, hours, date of month, month, day of week and year with leap year compensation valid up to 2100
56 byte nonvolatile RAM for general data storage
2-wrire interface (I2C)
Automatic power fail detect
Consumes less than 500 nA for battery back-up at 25'C

15. BC547 The BC547 transistor is an NPN Epitaxial Silicon Transistor.
The BC547 transistor is a general-purpose transistor in small plastic packages.
It is used in general-purpose switching and amplification BC847/BC547 series 45 V, 100 mA NPN general-purpose transistors.
Whenever base is high, then current starts flowing through base and emitter and after that only current will pass from collector to emitter

16. BIBILOGRAPHY
The Microcontroller and Embedded systems” by Muhammad Ali Mazidi and Janice Gillispie Mazidi , Pearson Education.
ATMEL 89S52 Data Sheets.

17. THANK ‘Q’