This document describes a project to design an automatic braking system for vehicles traveling uphill using a MEMS sensor. The system uses a MEMS sensor to detect vehicle acceleration and an ATmega32 microcontroller to process the sensor data and control DC motors via an L293D driver chip. When the vehicle's acceleration changes as it travels uphill, indicating a change in speed, the system automatically applies the brakes by slowing the motors to safely control the vehicle's speed on hills.

2. INTRODUCTION
• The aim of the project is to design and construction of a module used
for vehicles in the hill stations. Auto breaking system is used when
vehicle is moving upward direction.
• The project was divided into two phases. The First phase is to
demonstrate the application of MEMS. The second phase of the
project attempts controlling motors.
• MEMS (micro-electro-mechanical-systems) sensor is interfaced to
micro controller using I2c protocol, microcontroller receives the data
from the MEMS sensor and process it according to the data from the
sensor appliances are operated.

3. ATMEGA 32
Power
Supply
MEMS
sensor
LCD
Display
Driver Motor
1
Driver Motor
2
Block diagram

4. Atmega32 Micro Controller
•The Atmega8535 is a low-power CMOS 8-bit microcontroller
based on the AVR enhanced RISC architecture
•The Atmega8535 achieves throughputs approaching 1 MIPS per
MHz allowing the system designed to optimize power consumption
versus processing speed.
•The Atmel Atmega8535 is a powerful microcontroller that provides
a highly-flexible and cost-effective solution to many embedded
control applications.

5. Micro Electro Mechanical Systems
(MEMS)
Micro electro mechanical systems (MEMS) (also written as micro-
electro-mechanical, Micro Electro Mechanical or microelectronic and
micro electro mechanical systems) is the technology of very small
mechanical devices driven by electricity; it merges at the nano-scale
into nano electro mechanical systems (NEMS) and nanotechnology.
MEMS are also referred to as micro machines (in Japan), or micro
systems technology – MST (in Europe).

6. MEMS are made up of components between 1 to 100 micrometers
in size (i.e. 0.001 to 0.1 mm) and MEMS devices generally range
in size from 20 micrometers (20 millionths of a meter) to a
millimeter. They usually consist of a central unit that processes
data, the microprocessor and several components that interact with
the outside such as micro sensors.

7. Working
The power supply to the circuit is given through a step down transformer
which reduces the 230 Volts AC supply to 12V AC, that is converted into pulsating
DC supply through the bridge rectifier used in the circuit. Now the pulsating DC is
passed through a filter this filtered output is pure DC, this filtered output is then
given to a voltage regulator and a 5 Volts DC supply is obtained and used to power
the various components used in the circuit. This 5 Volts DC supply is given to 40th
pin of the Microcontroller which is VCC, 9th pin of the Microcontroller for the
RESET button, LCD segment, driver IC (L293D).

8. The port C of the microcontroller is attached a pull-up resistor and interfaced
with LCD. Port A is given to the MEMS sensor and port D is connected to the
L293D driver IC. MEMS sensor is interfaced to micro controller using I2c
protocol, microcontroller receives the data from the mems sensor and process it
according to the data from the sensor appliances are operated.The output from
the MEMS sensor is given to the microcontroller, this chip converts it into
digital data. The output from the microcontroller is processed and the output is
shown in the LCD display and accordingly the motor is driven with the help of
the driver IC. The driver IC L293D is connected to the port D of the
microcontroller and it controls the dc motors. The direction of the motors and
the speed control of the motors are controlled by the driver circuit. The motors
are connected to the wheels of the vehicle and as the speed changes the vehicles
starts moving

9. The MEMS sensor senses the acceleration of the vehicle and
it is displayed in the LCD screen. As the vehicle moves the
MEMS sensor displays the difference in the acceleration. As the
vehicle climbs up the hill the speed of the motor speed changes as
there is a change in the acceleration of the values in the X and Y
plane. This speed is changed as it is already mentioned in the
source code and accordingly the braking system is applied by
decreasing the speed of the vehicle when the given acceleration
values are reached. Thus automatically braking system is applied
on the vehicle by using MEMS sensor.

10. Project kit
This is the module of the safety auto brake of hill station vehicle. In this module
all the components are kept on a single board. In the figure we can see the
transformer, power supply unit, L293D driver IC, ATMEGA 32 microcontroller,
MEMS sensor, LCD display and the motors are connected to the wheels of the
vehicle

11. The acceleration of the vehicle is sensed by the 3-axis accelerometer MEMS
sensor and the acceleration is displayed in the LCD display. The acceleration of
the vehicle in the X and Y axis is shown in the LCD display. The below figure
shows the values displayed in the LCD after the vehicle starts moving.
As the vehicle climbs up the hill the speed change. The MEMS sensor
senses the change in the difference in the X and Y axis and gradually the
acceleration of the vehicle decreases. As a result safety auto brake is applied
automatically.
This is the final output of the project. As the vehicle climbs up the hill the
speed of the vehicle decreases and brakes are applied using the L293 D driver IC
circuit. As a result, the vehicle moves up the hill safely without slipping back.

12. Future scope
Since the project made now is just a prototype, in future it can be used in any
vehicle in order to provide safety in order to avoid accidents and collisions of the
vehicles. Regenerative braking is used in the vehicles and the energy is saved and
it is stored in the battery for later use. This type of braking can be used in any
hybrid vehicles and we can reduce the use of fossil fuels in the vehicles.

13. Conclusions
The project SAFETY AUTO BRAKE SYSTEM FOR HILL STATION
VEHICLE USING MEMS SENSOR has been successfully designed and tested.
It has been developed by integrating features of all the hardware components
used. Presence of every component has been reasoned out and placed carefully
thus contributing to the best working of the unit. Secondly, using highly advanced
IC’s and with the help of growing technology the project has been successfully
implemented.

14. THANK YOU.