Arduino UNO R3 ATmega328P ATmega16U compatible Development Board USB Cable

A very popular development board for making projects. original is manufactured in Italy but the cost of original board is very high, most of the times difficult for students to buy original uno board.
here is the solution to this problem. you can buy exact clone of arduino uno at very low price. direct buying from importers is always better than buying from eCommerce in terms of cost. you can buy low cost arduino uno r3 from below link

BUY ARDUINO UNO R3

ESP8266 wifi module

 The ESP8266 WiFi Module is a self contained SOC with integrated TCP/IP protocol stack that can give any microcontroller access to your WiFi network. The ESP8266 is capable of either hosting an application or offloading all Wi-Fi networking functions from another application processor. Each ESP8266 module comes pre-programmed with an AT command set firmware, meaning, you can simply hook this up to your Arduino device and get about as much WiFi-ability as a WiFi Shield offers (and that’s just out of the box)! The ESP8266 module is an extremely cost effective board with a huge, and ever growing, community.

This module has a powerful enough on-board processing and storage capability that allows it to be integrated with the sensors and other application specific devices through its GPIOs with minimal development up-front and minimal loading during runtime. Its high degree of on-chip integration allows for minimal external circuitry, including the front-end module, is designed to occupy minimal PCB area. The ESP8266 supports APSD for VoIP applications and Bluetooth co-existance interfaces, it contains a self-calibrated RF allowing it to work under all operating conditions, and requires no external RF parts.

There is an almost limitless fountain of information available for the ESP8266, all of which has been provided by amazing community support. In the Documents section below you will find many resources to aid you in using the ESP8266, even instructions on how to transforming this module into an IoT (Internet of Things) solution!

Note: The ESP8266 Module is not capable of 5-3V logic shifting and will require an external Logic Level Converter. Please do not power it directly from your 5V dev board.

Features:

• 802.11 b/g/n
• Wi-Fi Direct (P2P), soft-AP
• Integrated TCP/IP protocol stack
• Integrated TR switch, balun, LNA, power amplifier and matching network
• Integrated PLLs, regulators, DCXO and power management units
• +19.5dBm output power in 802.11b mode
• Power down leakage current of <10uA
• Integrated low power 32-bit CPU could be used as application processor
• SDIO 1.1 / 2.0, SPI, UART
• STBC, 1×1 MIMO, 2×1 MIMO
• A-MPDU & A-MSDU aggregation & 0.4ms guard interval
• Wake up and transmit packets in < 2ms
• Standby power consumption of < 1.0mW (DTIM3)

FROM WHERE TO BUY:

you can buy esp8266 in india through the following link at wholesale price.

BUY ESP8266 WIFI MODULE

UM 3561 Siren Generator

UM 3561 Siren Generator Sometimes we need a Siren sound generator to add in a Burglar alarm circuit or in Robot based circuit. The simple solution is the Siren generator IC UM3561. By using only a few components around this IC, it is easy to make a Siren Generator. By selecting the Pin connection of Sel 1 (Pin 6) and Sel 2 (Pin 1) we can select different tones.UM 3561 is a programmed ROM IC with an inbuilt oscillator. 

Only one external resistor and a speaker driver transistor are sufficient to make a simple siren generator. The IC requires 3 volts so it works off 2 Pen cells. If the power supply is a higher voltage , use a 3.1 volt Zener to regulate the power to the IC. Internal circuits of UM3561 Inside the IC, there is an Oscillator circuit and the frequency of oscillations is controlled by the external resistor connected to OSC 1(Pin 7) and OSC2 (Pin 8). A 240 K resistor is the recommended value but a 220K will give satisfactory results. Do not change this value, it will change the tone. The oscillations thus generated will be then transferred to a control circuit which functions based on the tone selection through the connections of SEL 1 (Pin 6) and SEL2 (Pin 1) . The control circuit passes the signal to an address counter and then to the ROM. The tone pulses thus generated will be available from the output pin 3. Since the sound is weak, an amplifier is necessary to get loud sound. A single NPN transistor will amplify the sound. If loud sound is needed, use a Darlington transistor. Speaker should be 8 ohms 0.2 watts. A small Mylar Speaker is an ideal choice. Tone Selection 4 Sounds like Police Siren, Fire Brigade sound, Ambulance Siren and Machine Gun sound can be selected by changing the pin connections of Sel.1 (Pin6) and Sel. 2(Pin 1).

4 wheel drive robo car

this is for those people who always want to make their own robot but don't know from where to start. you can make your first robot by simply using DPDT switches along with battery and 9 components. all you need to know is the concept of turning the motor in either direction. by changing the voltages of the motor manually using switches you can move your bot in forward backward or in any direction. I will upload the whole process along with components and circuit diagram very soon.

to buy visit

http://www.ebay.in/itm/261603109137?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

TO download physics of semiconductor devices by SM SZE click on the following link
SM sze PDF

DIFFERENT TYPES Of LED DIODE

This article is best for those people who want to know the different type of LED diodes available in the market. LED known commonly as Light emitting diode is used everywhere. From mobile phones to LED television and LED bulbs, there are numerous applications. LED diodes  are available in various shapes and sizes.

different types of led

the most commonly used and available is 5mm white LED diodes. These LED,s require a voltage of 2-3.5V and a current of 20ma. These led's are best to use in DIY projects and a lot of fun stuff.

TO KNOW HOW TO USE LED,S ACCORDING TO VOLTAGE READ

ABC OF LED

TO BUY LED AT REASONABLE PRICE 

BUY LED DIODES

MUSIC CHIP FOR BIRTHDAY GREETINGS

Want to make your own chip which can produce melodious sound "HAPPY BIRTHDAY" , Honsitak company manufactured a popular ic HK66T-08 which produces sound by adding few additional components. The functioning of HK66T-08 is similar to UM66 series. The circuit diagram of HK66T-08 is similar to UM66.
for more information READ: SOUND FROM IC