Arduino Uno: Hall Effect Sensor

While brainstorming ideas for our float, we stumbled upon a problem. How would we be able to calculate the length of the tether in the water? We thought of a few different ideas, but nothing very feasible. One day someone mentioned the Arduino Hall Effect Sensor to us. The Hall Effect is used in things such as bicycle speedometers. It uses the diameter of the wheel and calculates the speed of the rider by timing how long it takes for the sensor to make one rotation.

Hall Effect Sensor

1. We used the UA Package Hall Effect sensor. For more information visit this sheet. A sketch of the sensor and chart explaining which wires connect to the Arduino is below:

1. Hook up three wires (red, black, and blue) to the sensor and to the Arduino Uno. Connect the red wire to 5v, the black wire to GND, and the blue wire to Analog 0.  After making sure the connections are correct and you're ready to rock!

3. The code we modified for our tether spool was found here. If you would like to see the code we used go here and find the folder named Arduino - Hall Effect Sensor. Upload it to your Arduino Uno and then view the serial monitor. Every-time the magnet passes the sensor you should see this: