Transcript EMBEDDED SYSTEMS & ROBOTICS

Definition of Embedded
Systems
1.Embedded system: is a system whose principal function is not computational,
but which is controlled by a computer embedded within it.
2. A general computer is defined not to be an embedded system.
3. An Embedded system is some combination hardware and software ,either
fixed in capability or programmable ,that is specifically designed for a particular
function.
4.Any hardware system which is intended to do a specific task can be called as
embedded system
1.The situation we find ourselves today in the field of microcontroller
had its beginnings in the development of technology of integrated
circuit.
2.This development has enabled us to store hundreds of thousands
of transistors into one chip.
3.The first computers were made by adding external peripherals such
as memory ,input /output line, timers and others to it.
4. Further increasing of package density resulting in creating an
integrated circuit which contained processor & peripherals .That
is how the first chip containing a microcomputer later known as
MICROCONTROLLER has developed.
1. In 1981,Intel corporation introduced an 8 -bit microcontroller known as 8051.
2. It had 128bytes RAM,4Kbytes ROM,2timers,1 serial port & 4 ports on a single
chip.
3. It was referred as “System on a chip”.
4. Intel's original MCS-51 family was developed using
NMOS technology.
5. Later versions, identified by a letter C in their name (e.g., 80C51) used CMOS
technology and were less power-hungry than their NMOS predecessors.
:
1.4 KB on chip program memory.(ROM)
2.128 bytes on chip data memory(RAM).
3. 4 register banks.
4. 8-bit data bus
5.16-bit address bus.
6.16 bit timers (usually 2, but may have more, or less).
7.3 internal and 2 external interrupts.
8.Four 8-bit ports, (short models have two 8-bit ports).
9. 16-bit program counter and data pointer.
10.1 Microsecond instruction cycle with 12 MHz Crystal.
External interrupts
Interrupt
Control
On-chip
ROM for
program
code
Timer/Counter
On-chip
RAM
Timer 1
Timer 0
CPU
OSC
Bus
Control
4 I/O Ports
P0 P1 P2 P3
Address/Data
Serial
Port
TxD RxD
Counter
Inputs
P1.0
P1.1
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
RST
(RXD)P3.0
(TXD)P3.1
(INT0)P3.2
(INT1)P3.3
(T0)P3.4
(T1)P3.5
(WR)P3.6
(RD)P3.7
XTAL2
XTAL1
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
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18
19
20
8051
40
39
38
37
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Vcc
P0.0(AD0)
P0.1(AD1)
P0.2(AD2)
P0.3(AD3)
P0.4(AD4)
P0.5(AD5)
P0.6(AD6)
P0.7(AD7)
EA
ALE
PSEN
P2.7(A15)
P2.6(A14)
P2.5(A13)
P2.4(A12)
P2.3(A11)
P2.2(A10)
P2.1(A9)
P2.0(A8)
In this project the robot, is controlled by a mobile phone that makes call to
the mobile phone attached to the robot in the course of the call, if any
button is pressed control corresponding to the button pressed is heard at
the other end of the call. This tone is called dual tone multi frequency tone
(DTMF)robot receives this DTMF tone with the help of phone stacked in the
robot
The received tone is processed by the microcontroller with the help of
DTMF decoder MT8870 the decoder decodes the DTMF tone in to its
equivalent binary digit and this binary number is send to the
microcontroller, the microcontroller is pre programmed to take a decision
for any given input and outputs its decision to motor drivers in order to
drive the motors for forward or backward motion or a turn.
The mobile that makes a call to the mobile phone stacked in the
robot acts as a remote. So this simple robotic project does not
require the construction of receiver and transmitter units.
DTMF signalling is used for telephone signalling over the line in
the voice frequency band to the call switching centre. The version
of DTMF used for telephone dialling is known as touch tone.
DTMF assigns a specific frequency (consisting of two separate
tones) to each key s that it can easily be identified by the
electronic circuit. The signal generated by the DTMF encoder is
the direct alzebric submission, in real time of the amplitudes of
two sine(cosine) waves of different frequencies, i.e. ,pressing 5
will send a tone made by adding 1336hz and 770hz to the other
end of the mobile.
CIRCUIT DIAGRAM OF DTMF ROBO CAR
when you press 2 the robot will move forward
when you press 4 the robot will move left
when you press 8 the robot will move backwards
when you press 6 the robot will move right
when you press 5 the robot will stop.
APLLICATIONS
1) Scientific
Remote control vehicles have various scientific uses including hazardous
environments, working in the deep ocean , and space exploration. The majority
of the probes to the other planets in our solar system have been remote control
vehicles, although some of the more recent ones were partially autonomous.
The sophistication of these devices has fueled greater debate on the need for
manned spaceflight and exploration.
2)Military and Law Enforcement
Military usage of remotely controlled military vehicles dates back to the first
half of 20th century. Soviet Red Army used remotely controlled Tele tanks during
1930s in the Winter War and early stage of World War II.
3) Search and Rescue
UAVs will likely play an increased role in search and rescue in
the United States. This was demonstrated by the successful use
of UAVs during the 2008 hurricanes that struck Louisiana and
Texas.
4)Recreation and Hobby
See Radio-controlled model. Small scale remote control vehicles
have long been popular among hobbyists. These remote
controlled vehicles span a wide range in terms of price and
sophistication. There are many types of radio controlled
vehicles. These include on-road cars, off-road trucks, boats,
airplanes, and even helicopters. The "robots" now popular in
television shows such as Robot Wars, are a recent extension of
this hobby (these vehicles do not meet the classical definition of
a robot; they are remotely controlled by a human).
FURTHER IMROVEMENTS &
FUTURE SCOPE
1. IR Sensors:
IR sensors can be used to automatically detect & avoid
obstacles if the robot goes beyond line of sight. This avoids
damage to the vehicle if we are maneuvering it from a
distant place.
2. Password Protection:
Project can be modified in order to password protect the
robot so that it can be operated only if correct password is
entered. Either cell phone should be password protected or
necessary modification should be made in the assembly
language code. This introduces conditioned access &
increases security to a great extent.
3. Alarm Phone Dialer:
By replacing DTMF Decoder IC CM8870 by a 'DTMF
Transceiver IC’ CM8880, DTMF tones can be generated from
the robot. So, a project called 'Alarm Phone Dialer' can be built
which will generate necessary alarms for something that is
desired to be monitored (usually by triggering a relay). For
example, a high water alarm, low temperature alarm, opening
of back window, garage door, etc.
When the system is activated it will call a number of
programmed numbers to let the user know the alarm has been
activated. This would be great to get alerts of alarm conditions
from home when user is at work.
4. Adding a Camera:
If the current project is interfaced with a camera (e.g. a
Webcam) robot can be driven beyond line-of-sight & range
becomes practically unlimited as GSM networks have a very
large range.