Shields are boards that can be plugged on top of the Arduino PCB extending its capabilities.
Most shields are already made and are available in the market for a cheap price.
Some electronics enthusiasts may consider Designing their own custom made Shields which are able to perform simple tasks.
The main reason why custom shields are in high demand is that the user does not need to make electronic connections using a breadboard or a solderable perf-board. The connections are premade, the user has to only place the sensors or actuators in the right place, upload a code to the arduino, place the arduino on top of the shield, and you are good to go.
This custom made arduino shield expects an ARDUINO MEGA to be connected. The connections to the following are made:
Generic 5V RELAYS (x4)
HC05 (bluetooth module)
Serial Communication Ports (TX/RX)
PS2 Reciever
Servo Motors (x3)
Rotary Encoder
Ultrasonic Sensors (x2)
LDR (Light Sensor)
MPU9250 (consists of ACCELEROMETER, GYROMETER, MAGNETOMETER)
MDD10a (Dual H-bridge motor driver)
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