Blog - Sketching with Hardware

The Cardinator 3000

Published on: | Author: Sketching With Hardware | Categories: 2014b, Projects

The Idea
With the topic of UGVs (unmanned ground vehicle) we immediately wanted to create something that could help you in a playful way. While we were driving the car along on table we came up with an idea. The Cardinator 3000: a card dealing robot.
It will drive along the edges of the table, detects the players and deals cards to them. After the dealing process is finished it will stop and wait that cards will be inserted again so it can deal another round.

The Concept
Our vehicle has a card box with a motor that draws cards from the bottom of the card stack. In front of the box is a light barrier that detects when a card was pulled out. And there is also a light barrier on the back side of the box to detect if there are any cards left. An ultrasonic sensor on the left side of the car detects a player when the car drives by. It stops than and deals a card. To stay on the table the car has two infrared distance sensors mounted on the front-left and rear-left bottom of the vehicle. To initially start the dealing process and to control the vehicle we designed and Android App that communicates via an HC-05 Bluetooth module with the controller of the vehicle (an Arduino UNO).


The Card Dealing
For the card dealing mechanic we hacked an actuator to use it as dealing motor. We had to rasp off a little stopper on the bottom of one cogwheel and had to make sure that the potentiometer inside of the servo does not move anymore. To draw the cards we mounted a wheel of an old laser printer to the “motor”. It has a sticky rubber surface that is perfect to grab some paper (or in our case a card).
The card box looks like a dice and takes up the whole card playing theme. It was created with leftover plastic parts and a laser cutter. In front of the card ejection device is a light barrier that stops the motor when a card was pulled out from the bottom of the stack. On the rear side of the box is another light barrier that stops the whole program if there are no more cards left.

The Car Control
With the two infrared distance sensor we were able to detect the edges of the table. While driving forward the front sensor constantly sends the distance as analog value. When it detects that the distance is too far or respectively that the sensor is not above the table anymore the car stops. To stop the accelerated car it will not only stop it also drives backward for a few milliseconds. The same takes effect for driving backward in combination with the infrared sensor on the rear side.
After the front sensor was triggered the car starts with the corner driving process. First step of the process is to drive backward and steer left for a few milliseconds or till the rear infrared sensor was triggered. Then the car stops and drives forward and steers right for a few milliseconds or till the front infrared sensor was triggered. When the car was driving right without triggering the front infrared sensor the program will start again to drive forward till the front sensor triggers again. With that method it can drive along almost every edge. When both sensors were triggered it will drive right for a few milliseconds because the front sensor has more distance to the front wheels than the rear sensor to the rear wheels has.
The whole car was designed as a driving house of cards. Each card was cut and shaped from wooden panels with a laser cutter. The final prototype looks like this:

cardinator 3cardinator 4

The Video


linked categories 2014b, Projects


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