Acidity Tester
Project Summary
We built a robot to sort a set of beakers into "acidic" and "safe" liquids.
Project Description
This robot uses a Vernier pH Sensor to test the acidity of a solution. The NXT ultrasonic, light, and rotation sensors are used to find the solution and to track the robot's position. First, the robot rotates until the ultrasonic sensor finds a beaker, and then the robot advances towards that beaker. Once the robot reaches the beaker, a third motor lowers the pH sensor to test the pH of the solutions.
The two beakers are filled with plain water and vinegar. If the pH Sensor detects an acidic solution, the robot shouts and pushes the beaker towards the area marked "ACID". If the solution is not acidic, the robot says "good" and moves the beaker towards the "SAFE" side. Using the light and rotation sensors, the robot comes back to its starting location, finds the third beaker filled with distilled water, and rinses itself to comply with good laboratory procedure.
The pH Sensor can also be interchanged with any other Vernier probe that tests the properties of liquids, such as conductivity, temperature, salinity, etc.
The movie below shows a complicated Mindstorms program in action. For starting projects like this, we strongly recommend starting with a much simpler program (such as the MINDSTORMS NXT program download) which approaches a cup, sticks the pH sensor in the cup, and then makes noise if it finds an acid.
Demo Movie
Project Downloads
- Download the Acidity Tester MINDSTORMS NXT program »
- Download the Acidity Tester ROBOLAB program »
- Download the Acidity Tester building instructions (HTML format) »
- Download the Acidity Tester building instructions (LEGO digital designer format) »
Project Equipment
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