Friday, June 28, 2013

[TC] Remote controlled Spy Bot

Here is a remote operated spy robot circuit which can be controlled by using a wireless remote controller. It can capture audio and video information’s from the surroundings and can be sent to a remote station through RF signals. The maximum range is 125 meters. It overcomes the limited range of infrared remote controllers. This robot consists of mainly two sections. They are explained in detail below.

Remote Control Operated Spy Robot Circuit – Block Diagram

    Remote Control Operated Spy Robot Circuit - Block Diagram
Remote Control Operated Spy Robot Circuit - Block Diagram

1. Remote Control Section

The circuit uses HT 12E, HT 12D encoder and decoder. 433MHz ASK transmitter and receiver is used for the remote control. H-bridge circuits are used for driving motors. Two 12V DC/100RPM gear motors are used as drivers. The working of the circuit is as follows.
When we are pressing any key in remote controller the HT 12E generate 8 bit address and 4 bit data .The DIP switches are used for setting the address. Then the ASK transmitter sends the 8 bit address and 4 bit data to the receiver Then the ASK receiver receives the 8 bit address and 4 bit data and HT 12D decoder decodes the data, thus enabling the appropriate output. Thus the output signals that are generated controls the H-bridge which then rotates the motors.
The 433 MHZ ASK transmitter and receivers are extremely small, and are excellent for applications requiring short-range RF remote controls.  The transmitter module is only 1/3rd the size of a standard postage stamp, and can easily be placed inside a small plastic enclosure. The transmitter output is up to 8mW at 433.92MHz. The transmitter accepts both linear and digital inputs and can operate from 1.5 to 12 Volts-DC, and makes building a miniature hand-held RF transmitter very easy.  The 433 MHZ ASK transmitters is approximately the size of a standard postage stamp
433 MHZ ASK receivers also operate at 433.92MHz, and have a sensitivity of 3uV.  The receiver operates from 4.5 to 5.5 volts-DC.
Remote-Control-Operated-Spy-Robot-Circuit-Remote-Control-Section
Remote-Control-Operated-Spy-Robot-Circuit-Remote-Control-Section

2. Video Transmission Section

In this project we are using a wireless CCD camera. Now these types of cameras are commonly available in the market. It works on 12VDC supply.


The 12 Volt DC supply is taken from the battery placed in the robot. The camera has a receiver, which is placed in the remote station. Its output signals are in the form of audio and video. These signals are directly connected to a TV receiver or a computer through a tuner card.
Remote Operated Spy Robot - Remote Control Section
Remote Operated Spy Robot - Remote Control Section

Components Required

IC HT 12E 1
HT 12D 1

LM 7805 2
TRANSISTOR TIP 127 4

TIP 122 4

S 8050 4
DIODE 1N 4148 8
RESISTOR 1K 4

220E 4

39K 1

1M 1
ASK TRANSMITTER 433 MHz 1
ASK RECEIVER 433 MHz 1
DIP SWITCH
2
PUSH TO ON SWITCH
4
GEAR MOTOR 12V DC 100rpm 2
BATTERY 12V 1.3 Ah   rechargeable 1

9V 1
WIRELESS CCD CAMERA
1

Construction

The steps for the construction are…
1. Take a hylam sheet with (20cm*15cm) size.
2. Fix two gear motors (12VDC 100rpm) in the hylam sheet by using aluminum pieces and nut bolts as shown in the figure below.
3. Fix the ball castor as shown in the figure below.
Construction of Remote Operated Spy Robot Circuit
Construction of Remote Operated Spy Robot Circuit
4. Then fix the battery (12VDC 1.2Ah) on the top of the spy robot as shown in the figure below.
Construction of Remote Operated Spy Robot Circuit - Top View
Construction of Remote Operated Spy Robot Circuit – Top View
5. Connect two motors to the PCB. The PCB is then connected to the battery.
6. Connect the wireless CCD camera to the battery.
7. Connect the camera receiver to the TV or computer. Video information’s will thus appear in the screen.
8. Switch on the remote controller and control the spy robot


Source: http://www.circuitstoday.com/

Tuesday, June 25, 2013

[TC] ExpeditInvaders Shelf -Arduino Based LED Lighting Shelf






Currently ExpeditInvaders support 10 color sets (RGB, Rasta, CGA, Brazil, Fizz, Kitty, Neon, Lantern, Lemming, LeBron) and 6 animation modes (Random, Solid, Ordered, Checkboard, Weird, Weirdtwo). The best thing about ExpeditInvaders is, that you can use your feets to change the color set or animation mode. Under the shelf is a PS2 keyboard attached. The keyboard has a special key map installed, if a key on the left side is pressed the color set change, if a key on the right side is pressed the animation will change.
If you press ESC + Arrow Right ExpeditInvaders will save the current state to the EEPROM. This state will be restored next time ExpeditInvaders is restarted.

All you need to spice up your Expedit Shelf are two strands of LED modules, an Arduino board (doesn’t matter which one, can be an old Duemilanove or a new Leonardo) and an old PS2 Keyboard.

Step 1, align LED Modules
Align the modules like on this image (back view):

It should look like this, once you installed them:


Step 2: Connect Devices to Arduino
Connect Pin 13 to LED Module Clock, Pin 11 to LED Module Data and GND to LED Module GND.
Connect 5v and GND to the PS2 Module, Connect Data to Pin 2 and Clock to Pin 3.

You can use an Arduino without pinheaders (solder direct on the board) or you use a ProtoShield Kit.

Here is the PS2 connection schema (thanks to prjc.com, I ripped your image):


Step 3: (Hot) Glue keyboard under the shelf
Just hot glue the keyboard under the shelf, make sure the cable is correct aligned. Now you can kick your Arduino Project…



Step 4: Upload Firmware to Arduino
Get the ExpeditInvaders Firmware on my GitHub repo and upload it to your Arduino board.


Step 5: Connect 12V to the Arduino and LED Modules
Connect 12V to the Arduino and LED Modules. You can use an old ATX power supply or a new 12V/24Watt Power supply.


ANd You Are Done!
Links

More Images


 
 
 

Saturday, June 22, 2013

[TC] Haunted House Sound Effects Machine(Rasberry Pie)

People have been asking me about interesting applications for the Raspberry Pi, and whether Raspberry Pi is an Arduino killer of some sort. The answer to the second question is no; in fact it is an Arduino augmenter. This blog post answers the first question with another question: how about a Haunted House sound effects machine?

A new revision of the Early Release of Getting Started with Raspberry Pi came out last Friday. I read Matt Richardson’s chapter on using Pygame with the GPIO pins on the Pi, which included a simple Sound Sample player. I adapted his example to work with an Arduino that talks to the Pi over a serial connection; this skeletal (ahem) hookup could easily be incorporated into some sort of Halloween installation. I decided to use Arduino for reading the inputs because out of the box it is more robust and can handle a wider variety of inputs. Also, there are many existing Haunted House triggering demos out in the wild that use Arduino.
First, you’ll need to prepare the trigger circuit. The following example uses three toggle switches, but you can replace those with any kind of on/off input. In a haunted house (or porch-based trick-or-treater installation), a PIR sensor would be handy for triggering based on proximity.
Here’s the basic schematic:
http://todayscircuits.blogspot.in
The 10k resistors can be replaced by the Arduino’s own internal pull-up resistors, if you know how to do that.
I connected the Arduino to the Raspberry Pi using a USB cable. While I had the Pi hooked into a monitor, I found that I could just plug the Arduino through my Mac keyboard USB connector and it got enough power from that to work. If you have an older Raspberry Pi with polyfuses limiting the power on the USB port (check to see if you have 2 little green fuses marked “1104″ next to the USB ports), you may need an external hub, or run the Pi headless to free up a USB port.
Next, upload the following sketch to the Arduino:
// PiTalk.ino// Reads three digital inputs. These could be any kind of
// switch or (for Halloween) PIR sensors. byte onState[3] = { 0, 0, 0 }; // save the state of each pin void setup() { Serial.begin(9600); // Open serial connection pinMode(2, INPUT); // Set these three pins for reading pinMode(3, INPUT); // Each have a 10k pullup externally pinMode(4, INPUT); // so a trigger is LOW} void loop() { for (int i=0; i<3; i++) { // Iterate over pins if (digitalRead(i+2) == LOW) { // Check if triggered if (onState[i] == 0) { // Just triggered? Serial.write(i+2); // Send the pin number onState[i] = 1; // but just once }
} else { onState[i] = 0; // Not triggered } } delay(20);}You can use your computer to do upload the program, or you can download and install the Arduino IDE directly on the Raspberry Pi (as described in the next release of Getting Started with Raspberry Pi).Once the Arduino is programmed, open up the Leafpad text editor on the Raspberry Pi and enter this Python program, adapted from Matt’s Sound Sample Player:# playSounds.py import pygame.mixerfrom time import sleepfrom sys import exitimport serial pygame.mixer.init(44000, -16, 1, 1024)
soundA = pygame.mixer.Sound("Scream.wav")
soundB = pygame.mixer.Sound("WilhelmScream.wav")soundC = pygame.mixer.Sound("CastleThunder.wav") soundChannelA = pygame.mixer.Channel(1)
soundChannelB = pygame.mixer.Channel(2)soundChannelC = pygame.mixer.Channel(3) print "Sampler Ready."serialFromArduino = serial.Serial("/dev/ttyACM0",9600)serialFromArduino.flush() while True: try: val = ord(serialFromArduino.read()) print(val) if (val == 2):
soundChannelA.play(soundA)
if (val == 3): soundChannelB.play(soundB) if (val == 4): soundChannelC.play(soundC) val = 0 sleep(.01) except KeyboardInterrupt:
exit()
Save it as playSounds.py. Before you run the script you’ll probably need to install the Python serial module. To do that, type:
sudo apt-get install python-serial
If you’re running the latest Raspbian, you probably have everything you need to get this running. Open the LXTerminal and type:
python playSounds.py
If you get an error that Pygame is not installed, type:
sudo apt-get update
sudo apt-get install python-pygame
You’ll also need some sound files to play. I chose three from the Internet Archive: a generic scream, a Wilhelm Scream, and the classic Castle Thunder sample.
When you press the buttons each sound will play once; Pygame’s mixer will even play all three at the same time if you have multiple trick-or-treaters invading your porch


[TC] Connect Raspberry Pi to Projector or TV

final.png
When we have a meeting in a meeting room, we need to connect our laptop to a projector to show our desktop. But sometimes, several persons need to show their desktop, they need to change their laptop. This is complex and waste some time.
Currently, we have some mobile project, they are can be run in android/ios system. Before publish the project, we need to demo it to our team members or other guys. It is hard to demo them( in a phone) in the projector.

What I want to do is:
1. Write a video player in Raspberry Pi
2. Connect the Raspberry Pi to the Projector or TV
3. Write a desktop capture in a pc/mobile phone, and send the data to the Raspberry Pi
4. Who want to show their desktop in a pc/mobile phone, run the program to connect Raspberry Pi and it will show it in the Projector/TV

Step 1: Port FFmpeg/SDL to Raspberry Pi

player.png
How to write a video player in Raspberry Pi?
1. Port FFmepg/SDL to it.
 2. Write a server program to accept the pc/mobile phone to connect it
3. Call ffmpeg to play the network data.

Step 2: Implement the desktop capture in a pc

pc to pi.png
Implement the desktop capture in a pc.
1. Connect it the Raspberry Pi
2. We can call the system API to capture the desktop
3. Encode the data to h264 video.
4. Send the data to Raspberry PI 


Step 3: Implement program capture in a mobile phone

mobiletopi.png
Implement program capture in a mobile phone.
1. Connect it the Raspberry Pi
2. Find a way to capture the program UI
3. Encode the data to h264 video.
4. Send the data to Raspberry PI


Monday, June 17, 2013

[TC] Google Glass in Helmet Form

A Motorcyclist's Dream: Google Glass in Helmet Form



Using high-tech dashboards, drivers can reference navigation systems and voice control in the comfort of a quiet car, but motorcyclists still don't have an effective, high-tech solution. Referencing maps requires a roadside stop, and GPS systems can be distracting.
Now, the team at LiveMap is looking to fund a project that would bring built-in navigation and augmented reality to helmets. Think Google Glass in helmet form.
The motorycle helmet, which is currently listed on crowdfunding site Indiegogo, comes with technology and features so powerful only fighter pilots currently have access. The project already has the financial backing and support from the Moscow Department of Science and several other Russian organizations, but LiveMap is looking for additional funding to get it up and running.
Similar to F-35 fighter jet helmets, a colorful, translucent picture would project onto the visor and create a clear, unobstructed view. It would come with its own interface — not iOS or Android — and prevent users from watching videos or playing games while riding.

For long drives, the motorcycle helmet features two 3000-mAh batteries, a microphone for voice control that keeps both hands focused on driving and a digital compass for head movement tracking. In case a motorcyclist runs into trouble, the command "help" will notify local authorities.
LiveMap plans to ship the helmet in August 2014, with a price tag of $1,500 for devices purchased in June and $2000 for those purchased afterward. If you don't want to fully invest in the technology but still want to give it a try, you can donate $100 to the fund to try on a head set at an upcoming LiveMap promo party in the future.



Helmet




Sunday, June 16, 2013

Raspberry Pie History

Hello TC fans From Today onward We Are Going To Explain to About The Latest Module Discovered In Electronics History Called As " RASPBERRY Pie" And The Projects Based On It...




DeveloperRaspberry Pi Foundation
TypeSingle-board computer
Release date29 February 2012
Introductory priceUS$ 25 (model A) and US$ 35 (model B)
Operating systemLinux (Raspbian, Debian GNU/Linux, Fedora, and Arch Linux ARM) RISC OS, FreeBSD,NetBSD, Plan 9
Power2.5 W (model A)3.5 W (model B)
CPUARM1176JZF-S (armv6k) 700 MHz,Raspberry Pis can dynamically increase clockspeeds, and some can temporarily reach speeds up to 1 GHz.
Storage capacitySD card slot
(SD or SDHC card)
Memory256 MByte (Model A)
512 MByte (Model B rev 2)
256 MByte (Model B rev 1)
GraphicsBroadcom VideoCore IV
Websitewww.raspberrypi.org



[Tc] Google To Use 'Wireless Balloons' To Deliver Wi-Fi

Google will reportedly use Air balloons and satellites to provide Internet access to under-served countries. 

It is interesting that Google is planning to build wireless networks around the world in emerging markets such as Africa and Asia, but what’s more interesting is how the web giant plans to deploy this plan. The company is actually planning to offer Wi-Fi in these areas by using balloons. Yes, you heard us right! Not through the conventional cable strings but rather via flying balloons. 


Google, Google wi-fi, Google internet, Google services



As reported by the Wall Street Journal, Google is also supposedly planning to explore experimental methods to provide wireless connection to previously under served areas. These methods will include satellite Internet and the all new balloons plan, which will allegedly use high-altitude devices to blast wireless signals across hundreds of square miles.

This means that these aren’t just the conventional Wi-Fi routers tied on to the weather balloons. The devices will use different frequencies than those of television broadcasts.

So why is Google investing so much in hardware and engineering for underdeveloped areas? The Wall Street Journal in its report says that Google is just interested in increasing the user base into the Google sphere of apps and devices. This will in turn help Google to achieve considerable success in online advertising.

Way to go Google, you are doing some philanthropy too!


Friday, June 14, 2013

[TC] Secure Digital Access System using iButton


Access control forms a vital link in a security chain. Here we describe a secure digital access system using iButton that allows only authorised persons to access a restricted area.


The iButton is used here as a key to the access control system. Its unique identification (ID) number is used for authorisation. On detection of an authorised iButton, the system allows access. Thereafter, an automated lock key locks the system again. The system is permanently halted after five repeated false attempts. A service control unit built around an AVR microcontroller is interfaced to the iButton with 1-wire protocol for authentication of user validation of data.


iButton DS1990A
Here we have used the iButton DS1990A from Dallas Semiconductor (MAXIM). Its block diagram is shown in Fig.1.



Fig.1: Block diagram of iButton
An iButton is a chip housed in a stainless-steel enclosure (refer Fig.2). The electrical interface is reduced to the absolute minimum, i.e., a single data line plus a ground reference. The energy needed for operation is taken from the data line. The DS1990A serial number iButton is a rugged data carrier that acts as an electronic registration number for automatic identification. It contains a unique ROM code that is 64-bit long as shown in Fig.3. The first eight bits are a 1-wire family code. The next 48 bits are a unique serial number. The last eight bits are a cyclic redundancy check (CRC) of the first 56 bits.



Fig.2: A typical iButton chip

Data is transferred serially via the 1-wire protocol, which requires only a single data lead and a
ground return. The iButton DS1990A provides the additional 1-wire protocol capability that allows the search ROM command to be interpreted by the DS1990A.



Fig.3: 64-bit lasered Rom


Circuit description

Fig.4 shows the circuit of the secure digital access system using iButton. The circuit is built around an ATmega16 microcontroller.


Fig.4: Circuit of the secure digital access system using iButton


The ATmega16 is an 8-bit microcontroller based on the AVR enhanced RISC architecture that executes powerful instructions in a single clock cycle. It has 16kB in-system programmable flash program memory with read while- write capabilities, 512 bytes of EEPROM, 1kB SRAM, 32 general purpose input/output (I/O) lines, 32 general-purpose working registers,three flexible timers/counters with compare modes, internal and external interrupts, a serial programmable. USART, a byte-oriented two-wire serial interface, a programmable watchdog timer with internal oscillator, an SPI serial port and six software-selectable power-saving modes.

Piezobuzzer PZ1 is used as an audible indicator for true, fake, random touches and system halt. It is controlled from port pin PD6 of the microcontroller with the help of transistor T1. The iButton socket is connected to port pin PD2. Pull-up resistor R1 is used as required from the 1-wire protocol. Port pin PD4 controls the relay operation through optocoupler PC817 (IC2). The door locking mechanism, say, for a slide door, is connected to the contacts of relay RL1, which closes after some time automatically.

Whenever someone attempts to gain access by touching the iButton (IC5) using his own iButton, the firmware inside the AVR reads its unique ID and matches with the ID in the firmware. If the ID matches, port pin PD4 goes high, the internal LED of the optocoupler (IC2) glows and relay RL1 energises for the predefined time. Simultaneously, the buzzer sounds to indicate grant of access.

Thereafter, relay RL1 de-energises. The buzzer gets the PWM signal to produce sound from port pin PD6 of the microcontroller. The 1-wire communication is done through interrupt port pin PD2 (INT0), so the AVR does not have to poll the pin but respond when any change in signal is detected on the interrupt pin. Switch S1 is used for manual reset.

Port pin PD1 of the microcontroller is used to interface with the hyper terminal of the PC through RS-N 232 interface MAX232 IC (IC3) for iButton verification and checking. The microcontroller  provides a transmit channel for serial data transfer. Transmit data pin (TXD) is specified at port pin PD1. The microcontroller is connected to T1 IN (pin 11) of MAX232. T1 OUT (pin 14) of IC3 is connected to pin 2 of the Comport connector. The signals provided on these pins are TTL-level and must be boosted and inverted through a MAX232 converter to comply with the RS-232 standard.


The MAX232 has two internal charge pumps that convert +5V into ±10V (unloaded) for RS-232 driver operation. The first converter uses capacitor C6 to double the +5V input to +10VM on capacitor C8 at pin 2. The second converter uses capacitor C5 to invert +10V to -10V on capacitor C4 at pin 6.

The power supply for this circuit is derived from 230V, 50Hz AC mains. Transformer X1 steps down 230V, 50Hz AC mains to deliver a secondary output of 9V, 300 mA. The transformer output is rectified by a full-wave rectifier comprising diodes D1 through D4, filtered by capacitor C1 and regulated by IC 7806 (IC4). Capacitor C2 bypasses the ripples present in the regulated supply. LED1 acts as the power indicator and R5 limits the current through LED1.
Construction and testing
An actual-size, single-side PCB for the secure digital access system is shown in Fig. 5(View as PDF) and its component layout in Fig. 6(View as PDF). Assemble the circuit on a PCB as it minimises time and assembly  errors. Carefully assemble the components and double-check for any overlooked error. Connect the assembled circuit to the COM port of the computer. The iButton access code and message is transferred is to the PC through the COM port using the Hyper Terminal program.





Software
The software for this project is given at the end of this article. It is written in ‘Basic’ language and compiled using Bascom-AVR compiler. The source program is well commented and easy to understand.

Burn the finally obtained Intel hex code file into the AVR’s flash memory using a suitable programmer. The microcontroller uses an 8MHz internally generated clock. To activate, program fuse bytes as follows:


Fuse low byte = D4
Fuse high byte = 99

The source program is developed quickly with the help of the BASCOMAVR library function. The 1wrest, 1wread and 1wwrite functions are used for checking the presence of 1-wire device, reading of the unique ID of iButton and writing to the 1-wire device, respectively. Sound function is used for generating the beep sound from the buzzer. The iButton is connected to hardware interrupt pin INT0 so that any change on the pin can be detected and further processing for 1-wire done.
The program execution starts by initialising the input/output ports, the interrupt pin and its level of detection. Global interrupts are enabled and the interrupt service routine is ready to be executed when any interrupt is received. As soon as the normal program execution is interrupted, an interrupt is issued and the control of execution enters the interrupt service routine, where iButton is given reset command first and then the ROM command to fetch the unique ID of the iButton. This fetched ID is compared with the unique ID programmed in the firmware. If there is a mismatch between the two IDs, a fake parameter counter is incremented and the relay connected to port PD4 de-energises. If the two IDs match, the relay connected to port PD4 energises and simultaneously the buzzer connected to port PD6 sounds. If the unique ID is wrong sequentially five times, the system enters the major warning state where the buzzer sounds continuously and it can only be stopped by resetting the system


Author:Chirutkar Harshadkumar Govindrao And Dr. H.N. PandyaSource:http://www.electronicsforu.com/
 

Tuesday, June 4, 2013

[TC] Multiutility flash light















Multiutility flash light  



This multiutility flash light consists of three sections: a flasher, a sound-to-light display and a white LED-based flashlight.

The flasher circuit (Fig. 1) is built around an NE555 timer IC that is wired as an astable multivibrator. It flashes a pair of LEDs alternatively. The frequency of the astable multivibrator can be varied using preset VR1.



Fig. 1: Flasher circuit  
The working of the sound-to-light display (Fig. 2) is simple. The condenser microphone (MIC) picks up the sound in its vicinity and outputs a low voltage. The low output of the microphone is boosted by the first section (A1) of dual op-amp LM358. The output of op-amp A1 is fed to the second section (A2) of LM358 to drive transistor T1 (2N2222). The three RGB LEDs flash accordingly. (An RGB LED is actually a two-pin white LED package that glows red, green and blue sequentially when powered.) 




Fig. 2: Sound-to-light display circuit 


The flashing light circuit (Fig. 3) consists of a group of four white LEDs connected in series. Resistor R13 limits the current flowing through the white LEDs (LED8 through LED11).


Fig. 3: Flash light circuit


Assemble the entire circuit including the flasher, sound-to-light display and flashlight on a general-purpose PCB and enclose in a cabinet. Connect the flasher LEDs (LED1 through LED4) on top of the box and the condenser microphone and flashlight white LEDs (LED8-LED11) in the middle of top as shown in Fig. 4. Connect the three switches to select any one function or the combination of two or three sections.  



Fig. 4: Proposed arrangement for multiutility flash light

Source:http://electronicsforu.com/