The Hardware of The AdMoVeo consist of custom made parts as well as of prefabricated parts. Starting with the chassis, this is a self-designed part made from acrylic glass that was laser-cut within the /d.search-labs. On the chassis there are two geared DC-motors with wheels mounted. There is also a line follow unit mounted in the chassis and 2 battery holders for 4 AA rechargeable battery’s. On top of this there is a custom designed PCB holding the most of the electronics needed for this platform where on top the arduino board can be placed. Next all the sensors and actuators that are or can be on board will be described.
- Infrared distance sensors
Three infrared sender and receiver units are place on the robot, one pointing to the front, the other two pointing to the left and the right. With these sensors the robot is able to detect obstacles within a range of approximately 20 cm.
- Light sensors
At the front-side of the robot there are two light-sensors (LDR) places, one pointing with an angle of 45 degrees to the right, the other one pointing with the same angle to the left. These sensors can be used to find or follow a light-source.
- Sound sensors
Stereo sound detection can in an embedded application be used to detect the direction of the sound source, so there are two microphones on board.
- Line follower
mounted directly onto the chassis is a line follow PCB on where two infrared sensors are mounted that can be used to measure the reflection of the floor, when placed on a white floor with a black line on it a very distinct signal will be measured.
- Wheel encoders (optional)
There is an option to mount two encoder wheels and two detectors onto the robot.
The two geared Dc motors are controlled with a motor-driver that has a full h-bridge. Both motors can be controlled in direction and speed by making use of PWM outputs of the arduino.
A little buzzer is on the robot so it is able to get noticed… The buzzer needs a pulse-signal to make some noise, it is connected to a PWM-enabled pin.
To give the robot the ability to express it’s feelings (or just freshen up your room) it’s equipped with a RGB light that is located in the chassis.
The Arduino diecimila is equipped with a serial to USB conversion-chip that enables the user to simply upload new code trough the USB port. This USB communication can also be used to send over data to/from the computer and thus gives the possibility to monitor/control the robot this way.
- Xbee (optional)
An extra possibility to control/monitor the robot is to use a wireless communication modules called Xbee. Xbee (based on zigbee) has the possibility to send serial communication data wireless to an other xbee module and so gives the possibility the discard a physical cable. Note that the Arduino can NOT be programmed over Xbee, only though USB.
- Arduino Diecimila (addon board)
As central controlling unit a pre-fabricated Arduino diecimila is used, this board incorporates the right amount of functionality and easy of use for this robot, as it has multiple PWM & analog pins, a large open-source community and a lot of examples and descriptions on it’s site.
- The robot platform is powered by 4 high capacity rechargeable AA battery’s. The battery’s can be recharged within the robot by connecting a power adaptor to the attached Arduino board and switching the robot OFF.