1. PREFACE 1. 1 INTRODUCTION Radio control (often abbreviated to R/C or simply RC) is the use of radio signals to remotely control a device. The term is used frequently to refer to the control of model vehicles from a hand-held radio transmitter. Industrial, military, and scientific research organizations make [traffic] use of radio-controlled vehicles as well. A remote control vehicle is defined as any mobile device that is controlled by a means that does not restrict its motion with an origin external to the device.
This is often a radio control device, cable between control vehicle (Also called as RCV) differs from a robot in that the RCV is always controlled by a human and takes no positive action autonomously. One of the key technologies which underpin this field is that of remote vehicle control. It is vital that a vehicle should be capable of proceeding accurately to a target area; maneuvering with in that area to fulfill its mission and returning equally accurately and safely to base.
Recently, Sony Ericsson released a remote control car that could be controlled by any Bluetooth cell phone. Radio is the most popular because it does not require the vehicle to be limited by the length of the cable or in a direct line of sight with the controller (as with the infrared set-up ) . Bluetooth is still too expensive and short range to be commercially viable. 1. 2 HISTORY 1. 2 HISTORY OF REMOTE CONTROLLED VEHICLES The First Remote Control Vehicle I
Precision Guided Weapon: This propeller-driven radio controlled boat, built by Nikola Tesla in 1898, is the original prototype of all modern-day uninhabited aerial vehicles in air, land or sea. Powered by lead-acid batteries and an electric drive motor, the vessel was designed to be maneuvered alongside a target using instructions received from a wireless remote-control transmitter. Once in position, a command would be sent to detonate an explosive charge contained within the boats forward compartment.
The weapon’s guidance system incorporated a secure communications link between the pilot’s controller and the surface-running torpedo in an effort to assure that control could be maintained even in the presence of electronic countermeasures. To learn more about Tesla’s system for secure wireless communications and his pioneering implementation of the electronic logic-gate circuit read ‘Nikola Tesla – Guided Weapons & Computer Technology’, Tesla Presents Series Part 3, with commentary by Leland Anderson. Use of Remote Controlled Vehicles during World War II:
During World War II in the European Theater the U. S. Air Force experimented with three basic forms radio control guided weapons. In each case, the weapon would be directed to its target by a crew member on a control plane. The first weapon was essentially a standard bomb fitted with steering controls. The next evolution involved the fitting of a bomb to a glider airframe, one version, the GB-4 having a TV camera to assist the controller with targeting. The third class of guided weapon was the remote controlled B-17.
It’s known that Germany deployed a number of more advanced guided strike weapons that saw combat before either the V-1 or V-2. They were the radio-controlled Herschel’s Hs 293A and Ruhrstahl’s SD 1400X, known as ‘Fritz X’, both air-launched, primarily against ships at sea. 1. 3 TECHNOLOGY USED 1. 3 TECHNOLOGY USED Dual-Tone Multi-Frequency (DTMF) Dual-tone multi-frequency (DTMF) signaling is used for telecommunication signaling over analog telephone lines in the voice-frequency band between telephone handsets and other communication devices and the switching center.
The version of DTMF used for telephone tone dialing is known by the trademarked term Touch-Tone (canceled March 13, 1984), and is standardized by ITU-T Recommendation Q. 23. It is also known in the UK as MF4. Other multi-frequency systems are used for signaling internal to the telephone network. As a method of in-band signaling, DTMF tones were also used by cable television broadcasters to indicate the start and stop times of local commercial insertion points during station breaks for the benefit of cable companies.
Until better out-of-band signaling equipment was developed in the 1990s, fast, unacknowledged, and loud DTMF tone sequences could be heard during the commercial breaks of cable channels in the United States and elsewhere. TELEPHONE KEYPAD The contemporary keypad is laid out in a 3×4 grid, although the original DTMF keypad had an additional column for four now-defunct menu selector keys. When used to dial a telephone number, pressing a single key will produce a pitch consisting of two simultaneous pure tone sinusoidal frequencies.
The row in which the key appears determines the low frequency, and the column determines the high frequency. For example, pressing the ‘1’ key will result in a sound composed of both a 697 and a 1209 hertz (Hz) tone. The original keypads had levers inside, so each button activated two contacts. The multiple tones are the reason for calling the system multi frequency. These tones are the reason decoded by the switching center to determine which key was pressed. [pic] Fig 1. 1 A DTMF TELEPHONE KEYPAD | | 1209 Hz | 1336 Hz 1477 Hz | 1633 Hz | |697 Hz |1 |2 |3 |A | |770 Hz |4 |5 |6 |B | |852 Hz |7 |8 |9 |C | |941 Hz |* |0 |# |D |
TABLE 1. 1 DTMF KEYPAD FREQUENCIES (WITH SOUND CLIPS) | Event | Low Freq. | High Freq. | |Busy Signal |480 Hz |620 Hz | |Dial Tone |350 Hz |440 Hz | |Ring back Tone(US) |440 Hz |480 Hz | TABLE 1. 2 DTMF EVENT FREQUENCIES TONES #,*, A, B, C and D
The engineers had envisioned phones being used to access computers, and surveyed a number of companies to see what they would need for this role. This led to the addition of the number sign (#, sometimes called! octothorpe! in this context) and asterisk or ‘star’ (*) keys as well as a group of keys for menu selection: A, B, C and D. In the end, the lettered keys were dropped from most phones, and it was many years before these keys became widely used for vertical service codes such as *67 in the United States and Canada to suppress caller ID. The U. S. military also used the letters, relabeled, in their now defunct auto on phone system.
Here they were used before dialing the phone in order to give some calls priority, cutting in over existing calls if need be. The idea was to allow important traffic to get through every time. The levels of priority available were Flash Override (A), Flash (B), Immediate (C) and Priority (D), with Flash Override being the highest priority. 2. DESIGN OF THE PROJECT 2. 1. 1 PRELIMINARY DESIGN It contains mainly 3 parts They are 1. Block diagram 2. Components used 3. Circuit diagram 2. 1. BLOCK DIAGRAM: [pic] Fig 2. 1 BLOCK DIAGRAM DESCRIPTION: As shown in the above block diagram, first block is the Cell Phone. So, it acts as a DTMF generator with tone depending upon key pressed. DTMF Decoder, i. e. IC CM8870 decodes the received tone & gives binary equivalent of it to the microcontroller. The controller is programmed such that appropriate output is given to Motor Driver IC L293D which will drive the two DC Motors connected to it. The concept used for driving is ‘Differential Drive’. So, ultimately the two motors rotate according to the key pressed on the keypad of the cell phone. . 1. 2 COMPONENTS USED Table 2. 1 RESISTORS Table 2. 2 CAPACITORS |Value Quantity | |100k 2 | |10k 5 | |330k 1 | | | |Value Quantity | |0. 1uf 2 | |22pf 4 | Table 2. 4 OSCILLATORS Table 2. 4 ICs |Value Quantity | |3. 57 MHZ 1 | 12 MHZ 1 | |Value Quantity | |CM 8870 1 | |Atmega 16 1 | |74ls04 1 | |L 293 D NE 1 | |L 7805 CV 1 | Table 2. 5 MISCELLANEOUS: |Component Quantity | |12V 50 RPM DC MOTORS 2 | |DIODE 4007 1 | |RESET SWITCH 1 | |1. V DCBATTERYs 9 | |CONNECTING WIRES 7 | 2. 1. 3 CIRCUIT DIAGRAM Fig 2. 2 CIRCUIT DIAGRAM 2. 2 PROBLEMS ENCOUNTERED PROBLEMS FACED: Although the concept & design of the project seemed perfect, there were some problems faced while actual implementation. 1. Connecting Hands free of cell phone to DTMF decoder IC input: There were several types of hands free cords available in the market, the right one had to be chosen from them. Several ways to break up the cords and connect them to the input of IC 8870 were tried & some were newly developed by us (e. . Connecting Audio Jack of Pc’s speakers to the cell phone with help of an extender). SOLUTION: Finally Hands free cord’s Earplugs were removed & resulting set of wires were connected in an appropriate manner to the Decoder IC’s input. 2. SELECTION OF MOBILE PHONE: At first, latest cell phone like NOKIA 5700, N-series were tried. But they couldn’t give any output. Several cell phones were tested with their respective Hands free cords. SOLUTION: The older version phones like NOKIA 1100, NOKIA 2300 were found to be more suitable for the purpose. Finally NOKIA 1100 was used. 2. 3 FINALDESIGN 2. 3 FINAL DESIGN: 2. 3. 1. PCB LAYOUT: pic] Fig 2. 3 PCB LAYOUT 2. 3. 2. CIRCUIT DESCRIPTION: The important components of this robot are a DTMF decoder, microcontroller and motor driver. A CM8870 series DTMF decoder is used here. All types of the CM8870 series use digital counting techniques to detect and decode all the 16 DTMF tone pairs into a 4-bit code output. The built-in dial tone rejection circuit eliminates the need of pre-filtering. When the input signals are given at pins 1(IN+) & 2(IN-), a differential input configuration is recognized to be effective, the correct 4-bit decode signal of the DTMF tone is transferred to (pin 11) through (pin14) outputs.
The pin 11 to pin 14 of DTMF decoder are connected to the pins of microcontroller (P 1. 4 to P 1. 7). The atmega16 is a 8-bit micro control, has 64 kb Flash micro controller with 1 kb RAM. It provides the following features: 64 kb of on-chip Flash program memory with ISP (In-System Programming) and IAP (In-Application Programming), Four 8-bit I/O ports with three high-current Port 1 pins (16 mA each), Three 16-bit timers/counters. Outputs from port pins P0. 0 through P0. 3 and P0. 7 of the microcontroller are fed to the inputs IN1 through IN4 and enable pins (EN1 and EN2) of motor driver L293D IC, respectively to drive two geared dc motors.
Switch S1 is used for manual reset. The microcontroller output is not sufficient to drive the dc motors, so current drivers are required for motor rotation. The L293D is quad, high-current, half-h driver designed to provide bidirectional drive currents of up to 600mA at voltages from 4. 5V to 36V. It makes it easier to drive the dc motors. The L293D consists of four drivers. Pins IN1 through IN4 and OUT1 through OUT4 are the input and output pins, respectively of driver 1 through driver 4. Drivers 1 and 2, and driver 3 and 4 are enabled by enable pin 1(EN1) and pin 9(EN2), respectively.
When enable input EN1 (pin 1) is high, drivers 1 and 2 are enabled and the outputs corresponding to their inputs are active. Similarly, enable input EN2 (pin9) enables drivers 3and 4. The motors are rotated according to the status of IN1 to IN4 pins of L293D which in turn are depending on output pins of microcontroller, viz. , P0. 0-P0. 3. 2. 3. 3. PROGRAM CODE: FILENAME: Projrct_Final. asm ; CELLPHONE OPERATED LAND ROVER ; P1. 4-P1. 7 —> atmega16 i/p —> Connected to DTMF o/p P0. 0-P0. 3 —> atmega16 o/p —> Connected to L293D org 0000h mov p1, #0ffh ; Make P1 as i/p port L1: mov a, p1 anl a, #0ffh jne a, #0b0h, L2 ; DTMF o/p=2 mov p0, #8ah ; M1 & M2 both forward ljmp L1 L2: cjne a, #0e0h, L3 ; DTMF o/p=8 mov p0, #85h ; M1 & M2 both Reverse ljmp L1 L3: cjne a, #50h, L4 ; DTMF o/p=5 mov p0, #80h ; M1 & M2 both off ljmp L1 L4: cjne a, #0d0h, L5 ; DTMF o/p=4 mov p0, #86h ; M1= Rev , M2= Fwd ljmp L1
L5: cjne a, #90h, L1 ; DTMF o/p=6 mov p0, #89h ; M1= Fwd, M2= Rev ljmp L1 end 2. 3. 4. FLOW CHART: Fig 2. 4 Flow chart 3. SCOPE OF THE PROJECT The main contents of this scope of the project is 1. Applications 2. Advantages 3. Disadvantages 4. Further improvements & future scope 3. 1 APPLICATIONS: 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. The Voyager I spacecraft is the first craft of any kind to leave the solar system. The Martian explorers Spirit and Opportunity have provided continuous data about the surface of Mars since January 3, 2004. 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 Teletanks during 1930s in the Winter War and early stage of World War II. There were also remotely controlled cutters and experimental remotely controlled planes in the Red Army. Remote control vehicles are used in law enforcement and military engagements for some of the same reasons. The exposures to hazards are mitigated to the person who operates the vehicle from a location of relative safety. Remote controlled vehicles are used by many police department bomb-squads to defuse or detonate explosives. See Dragon Runner, Military robot.
UAV’s can hover around possible targets until they are positively identified before releasing their payload of weaponry. Backpack sized UAV’s will provide ground troops with over the horizon surveillance capabilities. 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. 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). Radio-controlled submarine also exist. 3. 2 ADVANTAGES: 1. Wireless control. 2. Surveillance System. 3. Vehicle Navigation with use of 3G technology which is almost available everywhere. 4. This wireless device has no boundation of range and can be controlled as far as network of cell phone 3. DISADVANTAGES: 1. Cell phone bill. 2. Mobile batteries drain out early so charging problem. 3. Cost of project if Cell phone cost included. 4. Not flexible with all cell phones only a particular, cell phone whose earpiece is attached can only be used 3. 4 FURTHER IMPROVEMENTS & FURTHER 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. 4. BIBLIOGRAPHY 1. Wikipedia – The free encyclopedia 2. http://www. 8051projects. info/ 3. http://www. instructables. com/ 4. Cell phone operated land rover ‘Electronics for You’ Magazine, Edition (July 2008) 5. DTMF Tester”, ‘Electronics For You’ Magazine, Edition (June 2003) 6. http://www. alldatasheet. com/ 7. http://www. datasheet4u. com/ 8. http://www. datasheetcatalog. com/ 5. DATASHEETS 5. DATA SHEETS PINACLE ENVIRONMENT: [pic] Fig 5. 1 PINACLE ENVIRONMENT AVR SPI PROGRAMMER: [pic] Fig 5. 2 AVR SPI PROGRAMMER ———————– START READ THE INPUT FROM DTMF DECODER (PORT 1) IF INPUT=2 M1= FWD M2= FWD CALL APPROPRIATE DELAY IF INPUT=8 IF INPUT=5 IF INPUT=4 M1= REV M2= REV M1= STOP M2= STOP M1=REV M2= FWD CALL APPROPRIATE DELAY CALL APPROPRIATE DELAY CALL APPROPRIATE DELAY IF INPUT=6 M1= FWD M2= REV CALL APPROPRIATE DELAY