It uses 8 SG90 / MG90 Servo motors as actuators for the legs, consists of a custom PCB made to power and control the servos and the Arduino Nano.PCB has dedicated slots for IMU module, Bluetooth module and even IR sensor array to make the robot autonomous. Body is made from laser cut 3mm acrylic sheets, can be 3D printed as well. Its a great project for enthusiasts to explore inverse kinematics in robotics.

I design my PCBs in Altium software (to download click here) . 12 SG90/MG90 servos can consume upto 4-5 Amps if all working simultaneously, thus the design requires higher current output capabilities. I've used 7805 Voltage regulator for powering the servos, but it can output max 1 Amp current. To solve this issue, 6 LM7805 ICs are connected in parallel to increase current output.

Schematics and Gerber can be found here.

Features of this design include:

• MPU6050/9250 is used for angle measurement
• Upto 6 Amp current output
• Isolated Servo power supply
• HCsr04 Ultrasonic Sensor output
• Peripherals for Bluetooth and I2C are also provided.
• All analog pins are provided on a Relimate for connector of Sensors and actuators
• 12 Servo outputs
• Power Indication LED

Specifications of PCB:

• Size of the PCB is 77 x 94 mm
• 2 layer FR4
• 1.6 mm

The design has separate 5V for the servos and Arduino. Check for shorts with ground at all individual power rails i.e Arduino 5V output, Servo VCC output and input 12V phoenix.

Once the PCB is checked for shorts, Arduino is ready to be programmed. The test code is available on my github.