The Arduino Robot and how to use microcontrollers in robotics

Launched in May 2013, the Arduino Robot is billed on the Arduino website as “the first official Arduino on wheels”. It consists of two circular microcontroller boards connected together with ribbon cable. The upper control board includes a micro SD slot, a colour LCD display, a speaker, three LEDs (one to indicate power, the other two to indicate USB communications via the USB port) and a compass chip. Underneath, the lower motor board includes a compartment for four rechargeable AA batteries (supplied), two wheels, two motors, a power switch and connector and five infrared floor sensors. Both boards feature the ATmega32u4 processor.

Advice on programming the robot is available on the Arduino website in the form of online Arduino robot tutorials. Users who purchase Arduino Robotic kits will find that they also contain an informative step-by-step guide to eleven different Arduino Robot projects as well as a GUI. For those who prefer more animated and visual instructions, however, the ten Arduino robot tutorial videos based on the Arduino start kit (and collaboratively produced by RS Components and Arduino) are probably the best option.

Both of the processors include integral USB communications, making it much easier to make the robot visible to a connected computer because no secondary processors are required. It will appear as CDC serial/Com port.

The Robot boards are considerably more pre-configured than other Arduino microcontrollers, having many of their I/O pins pre-mapped onto integral actuators and sensors to ensure smooth and easy functioning. However the device does have several TinkerKit connections for additional plug-in expansion boards (shields).

Important technical elements

The Arduino Robot has an operating voltage of 5V and each of the two processors come with 32 KB of flash memory for data processing, and 2.5 KB of SRAM. The clock speed is set at 16Mhz, and there are 4 digital I/O pins, which also double as analogue input channels. The robot has a diameter of 19 cm and stands 10 cm tall.

Technical illustration of the Arduino Robot and examples of Arduino Robot projects

The dual processors permit the robot to manage a large amount of data, to make decisions based on the data, and to execute a series of different tasks arising from those decisions.

A number of the connector pins on the Robot have specialised functions. For example, pins TK0 to TK7 on the control board can act as analogue inputs for collision-detecting switches, distance sensors and ultrasound sensors, while pins TKDO to TKD5 are digital input or output ports linked up directly to the processor.

The device can be configured to be remotely controlled with a universal TV remote, and with the relevant code on the IDE, it can be programmed to sense and avoid obstacles in its vicinity. An adaptation of this is to use the robot’s distance sensor to literally run away when an object (or person) pursues it. The robot can be programmed to seek out and find hidden objects in a maze and it can also be programmed to use the motor board’s infrared-array sensor to follow lines. The LCD display can be configured to play sounds and music through the speakers as well as to show images. Using the integral keyboard, the robot can be instructed where to go and it can also be programmed to function as a “disco bot” – dancing to the beat of its 8-bit jukebox.

Information about Arduino Robot kits

Arduino Robot kits, in addition to the robot device itself, also contain a USB cable, an AC to DC power supply cable to charge the batteries, 4 alkaline AA batteries and a detailed instruction manual for how to set it up and programme it to perform various tasks. Also included is a brand new version of Arduino’s IDE software, a micro-SD card and an LCD display which can be used on other Arduino boards as well.

Comparison to other Robot boards

The range of tasks which the Arduino Robot can be programmed to undertake is impressive. However, a less pricey alternative is the Polulu 3i robot. This device incorporates five reflective sensors, a less sophisticated LCD than the Arduino, and a single ATmega328 microcontroller. Its range of capabilities is, however, considerably more limited that the Arduino. Additional capability can be obtained with the Polulu m3pi robot, which has an expansion board as the second tier above its robot base. The expansion board includes enhanced processing power via a potent 32-bit mbed development board. However, it still lags well behind the Arduino Robot in capabilities.