Things you need to build an Arduino Robot 1) Platform -Body 2) Arduino microcontroller - Brain 3) Sensors -Sensitivities
Let's first talk about Platform There are all kinds of platforms in the current market, mostly there are five kinds: 1)2WD (Two wheel driving robot platform) 2)4WD (Four wheel driving robot platform) 3) Tracked Robot (looks like a small tank) 4) Robot Legs 5) Robot Arms Note: You might wanna check this robot website:www.ecerobot.com It also provides some great Arduino example codes for beginners.
Secondly, Arduino microcontroller 1)Arduino UNO 2)Arduino Mega 2560 3)Arduino ADK
For most of time, people attach an expansion shield on the top of microcontrollers to make the wire connections easier. Connect microcontrollers to sensors by using 3p Jumper wires Arduinio MEGA 2560 is strongly suggested. It has 54 digital input/output pins (of which 14 can be used as PWM outputs) and 16 analog inputs, which can carry more sensors and make your robot acts more dynamic.
The last but not the least – Sensors Arduino Sensors Digital Temperature Sensor Dual-Axis Joystick MQ-2 Gas Sensor Relay Module Big Button Module RB URF v1.1 Ultrasonic Sensor Virbration Sensor Buzzer Module Mini IR Detector Photoelectric Sensor Mini IR Line Tracking Sensor Magnetic Sensor IR receiver Sensor IR Transmitter Sensor One-way Tilt Sensor Light Sensor IR Wireless Remote Kit MQ-3 Gas sensor(Ethanol) Analog Voltage Divider Digital LED Module Infrared Pyroelectricity Sensor Triple Axis Accelerometer DHT11 Temperature and Humidity Sensor Flame Sensor Analog 300 Rotation Sensor WiiChuck Adapter Bumper Switch Check over at www.ecerobot.com and find out the right sensors for your robot