This is the -30 to 30 Amp current sensor breakout board from Pololu. It can sense current in both directions, with a resolution of 66 mV/A. Large terminals for soldering or connecting with ring terminals. Uses only one analog pin on your Arduino. 
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Is it hot in here? This digital temperature sensor will tell you, with 9 to 12 bit resolution! Uses only 1 wire to the microcontroller for communication. Simple to use and highly accurate. See our tutorial section for instructions and Arduino software. 
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This pack includes an LCD module of your choice, and everything else you need to connect it to your Arduino. See our Tutorial section for step by step instructions. Soldering is required, but the male header pins are included. 
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LCD Keypad shield for Arduino. This Arduino shield includes a 16x2 HD44780 White on Blue LCD module and a 5 push button keypad for menu selection and user interface programming. Fully assembled. This Shield uses Arudino LCD4Bit library. 
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The world's first and only open-source hardware charger! New version! Works with the new iPhone 4 and more! Make your own iPod/iPhone/GPS/etc... battery-pack and recharger! 
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IRL520N, N CHANNEL POWER MOSFET, 100V, 10A, TO-220 package. 
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IRL530N PBF, N CHANNEL POWER MOSFET, 100V, 17A, TO-220AB package, lead free.
This thing can drive LARGE loads, and be switched on and off with an I/O pin from your Arduino/microcontroller. 
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Make your own Arduino motion sensor / detector. Maybe you want something to happen when you walk into a room, like make the lights turn on, or have your theme song play whenever you enter. See our tutorial for using this sensor. 
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Standard NPN BJT Transistor, 2N4401. 40v/600mA max. 
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Photoresistor/Light Sensor
This little sensor detects light intensity. More light allows more current to flow. Use this sensor to turn something on/off when it is day/night, follow a light source, etc. 
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Piezo Buzzer, a loud one. Plug this directly into an Arduino/microcontroller IO pin and use it to signal events. With no resistor, this thing is LOUD. But you can tone it down as low as needed with a resistor or potentiometer. 
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Standard PNP BJT Transistor, 2N4403. 40v/600mA max. 
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10k Linear Trimming Potentiometer, breadboardable (see photo). Good for analog to digital converter input. Use this to set a variable input for control. 
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Prototyping shield for Arduino Mega. This prototyping shield for Arduino Mega comes fully assembled, and includes a large prototyping area, plus an SOIC pad for a surface mount chip with up to 26 pins. 
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Prototyping shield for Arduino. This prototyping shield for Arduino comes fully assembled, and includes a solderless breadboard, a large prototyping area, and an SOIC pad for up to 14-pin SOIC chip. 
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This little magnet is crazy strong. Seriously, put 2 of them together and it is difficult to separate them! Perfect for reed switches. 
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Red LED, 5mm, clear
Warning, warning, the Red LED is on! 
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Red LED, 5mm, diffused
Warning, warning, the Red LED is on! 
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Reed Switch
This is a non-contact magnetic switch. Put a magnet near it and the switch closes, and current flows. Take the magnet away, and the switch opens. Perfect for detecting doors opening, etc. 
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Relay shield for Arduino. This shield makes it easy to switch high current loads. Large screw terminals for wire connection. Fully assembled with 4 relays on board, each rated at 3 Amps. Also includes an xbee socket for use with wireless xbee modules. 
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