Easy to use flight controller. No computer is needed. Has LCD screenand 4 buttons which you can set the options.

The KK2.1.5 is next big evolution of the first generation KK flight control boards. The KK2.1.5 was engineered from the ground up to bring multi-rotor flight to everyone, not just the experts. The LCD screen and built in software makes install and setup easier than ever. A host of multi-rotor craft types are pre-installed, simply select your craft type, check motor layout/propeller direction, calibrate your ESCs and radio and you’re ready to go! All of which is done with easy to follow on screen prompts!

The KK2.1.5 added polarity protection to the voltage sense header and a fuse protected buzzer outputs, in case something is accidentally plugged in incorrectly. The voltage sense line has been updated for better accuracy. The board is clearly labeled and the voltage sense line color has been changed to red for easy identification, making installation and connections a snap.
 

Specs:
Size: 50.5mm x 50.5mm x 12mm
Weight: 21 gram (Inc Piezo buzzer)
IC: Atmega
Gyro/Acc: InvenSense Inc.
Auto-level: Yes
Input Voltage: 4.8-6.0V
AVR interface: standard 6 pin
Signal from Receiver: 1520us (5 channels)
Signal to ESC: 1520us

Firmware Version: 1.6:
Pre-installed firmware.
Dualcopter
Tricopter
Y6
Quadcopter +
Quadcopter X
Hexcopter +
Hexcopter X
Octocopter +
Octocopter X
X8 +
X8 X
H8
H6
V8
V6
Aero 1S Aileron
Aero 2S Aileron
Flying Wing
Singlecopter 2M 2S
Singlecopter 1M 4S

(Custom Mix via the "Mixer Editor" option)

The Mixer Editor allows you to adjust where and how much signal the motors receive from stick input and sensors. This allows you to create any configuration possible with up to 8 motors or servos.
 

What is a Multi-Rotor Control board you ask?

The KK2.1.5 Multi-Rotor controller is a flight control board for multi-rotor aircraft (Tricopters, Quadcopters, Hexcopters etc). Its purpose is to stabilize the aircraft during flight. To do this it takes the signal from the 6050MPU gyro/acc (roll, pitch and yaw) then passes the signal to the Atmega644PA IC. The Atmega644PA IC unit then processes these signals according the users selected firmware and passes control signals to the installed Electronic Speed Controllers (ESCs). These signals instruct the ESCs to make fine adjustments to the motors rotational speed which in turn stabilizes your multi-rotor craft.

The KK2.1.5 Multi-Rotor control board also uses signals from your radio systems receiver (Rx) and passes these signals to the Atmega644PA IC via the aileron, elevator, throttle and rudder inputs. Once this information has been processed the IC will send varying signals to the ESCs which in turn adjust the rotational speed of each motor to induce controlled flight (up, down, backwards, forwards, left, right, yaw).