RepRap Arduino Mega Shield, or RAMPS for short. It is designed to fit the entire electronics needed for a RepRap in one small package for low cost.

The modular design includes plug in stepper drivers and extruder control electronics on an Arduino MEGA shield for easy service, part replacement, upgrade-ability and expansion.

Features

• 3 PWM controlled mosfet powered outputs.
• Power and Thermistor Support for 2nd Extruder.
• Heated bed control with 11A fuse
• 3 thermistor circuits, 2x Extruder, 1x heatbed.
• 5 stepstick Stepper Driver sockets 
• 6 sets of Digital Pins in headers with VCC and GND for endstops 
• Extra pins broke out : PWM, digital, serial, SPI, I2C and analog
• Supports Bluetooth and SD card add on upgrades
• Expandable to control other accessories. such as Fans etc
• Fused at 5A for additional safety and component protection
• Thermal Overload Protection circuit
• LEDs indicate when heater outputs on

For Merlin firmware for RAMPS, click here

For Sprinter firmware for RAMPS, click here

For more info about RAMPS and circuit diagram, click here