Arduino Voltage Reader Code That Utilizes

Arduino Voltage Reader Code That Utilizes

This is a very simple Arduino code that utilizes the interrupt pin 0 (digital pin 2) of the Arduino.

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Use a Hall effect sensor to detect the presence of a magnet and make a speedometer, a burglar alarm, and more.

For instance, if we need to detect a door closing; then we simply have to attach a magnet to the door and a hall sensor to the frame of the door.

Whenever the door closes, the magnet is placed near the hall effect sensor and we are able to detect that the door has been closed.

If a magnet is attached to the wheel and a Hall Effect sensor is placed somewhere in the frame of the bike, the time taken for the wheel to complete one revolution can be measured, and with a bit more math, we can detect the bikes movement speed How Does It Work The Hall effect sensor works on the principle of the Hall effect, which states that whenever a magnetic field is applied in a direction perpendicular to the flow of electric current in a conductor, a potential difference is induced.

This voltage can be used to detect whether the sensor is in the proximity of a magnet or not.

The Arduino can detect this voltage change through its interrupt pin and determine whether the magnet is near the sensor or not.

The basic working of the Arduino Hall effect sensor is shown in the picture below.

For applications where the speed of detection is not crucial, ordinary Hall effect sensors like 44E can be used.

However, for applications that involve high-speed detection, like in the case of speedometers, high-frequency Hall effect sensors like US5881 or US1881 should be used.

There are two main types of Hall effect sensors: latching and non-latching.

The sensor gives out an output HIGH (5V) voltage whenever the north pole of a magnet is brought close to it.

Even when the magnet is removed, the sensor still outputs a HIGH voltage and does not go LOW (0V) until the south pole of the magnet is brought close to it.

The sensor gives an output HIGH voltage whenever the north pole of a magnet is brought close to it, and switches LOW whenever the magnet is removed.

I personally prefer non-latching Hall effect sensors like the US5881 for my projects.

Hall effect sensors have three pins: VCC(5V), GND, and Vout(Signal).

The GND of the sensor is connected to the GND pin on the Arduino.

The Vout or signal pin of the Hall effect sensor is connected to the Arduinos interrupt pin (digital pin 2).

Furthermore, a 10K resistor is connected between the VCC and Vout pins of the Hall effect sensor.

This is done to pull the output of the Hall effect sensor to 5V.

The connections are done as shown below (the side with the printed number is facing toward you in the diagram).

The Arduino Hall effect sensor code can be used to detect a magnet and count the number of times it detects it.