The name says it all on this one. An ATmega328P in DIP package, pre-loaded with the Arduino Optiboot (Uno 16MHz) Bootloader. This will allow you to use Arduino code in your custom embedded project...

The name says it all on this one. An ATmega328P in DIP package, pre-loaded with the Arduino Optiboot (Uno 16MHz) Bootloader. This will allow you to use Arduino code in your custom embedded project without having to use an actual Arduino board. To get this chip working with Arduino IDE, you will need an external 16MHz crystal or resonator, a 5V supply, and a serial connection. If you are not comfortable doing this, we recommend purchasing the Arduino Uno board that has all of these built into...

This Relay Shield v2.0 from Evil Mad Scientist is a simple Arduino add-on that gives your Arduino the ability to control a single electromechanical relay for switching loads of up to 24VDC or 40VAC....

This Relay Shield v2.0 from Evil Mad Scientist is a simple Arduino add-on that gives your Arduino the ability to control a single electromechanical relay for switching loads of up to 24VDC or 40VAC. Each Relay Shield comes equipped with a single pole - double throw (SPDT) sealed relay which can handle a current load of up to 5A. This means that when current is applied to the coil it throws a simple changeover switch, terminating the connection from the NC (Normally Closed) contact to ground...