Posts tagged Arduino Project
Arduino Pitot Tube Wind Speed and Airspeed Indicator - Theory and Experiments

The pitot tube is a device used to approximate the speed of vehicles traveling by air and water. An in-depth article on NASA's website is dedicated to pitot tubes (also called pitot-static tubes, Prandtl tubes), where it cites the primary application as airspeed indicator on aircraft. For more information on design and limitations of the instrument, I recommend perusing that page. For this tutorial, only the basic theory is explored using Bernoulli's equation and a practical application. An inexpensive pitot tube and a digital differential pressure sensor are used to measure pressure, which is converted to a digital signal using an Arduino board.

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Arduino Thermistor Theory, Calibration, and Experiment

Thermistor, whose name is derived from a combination of thermal and resistor, is a temperature sensing device that registers changes in internal resistance as a function of temperature. Thermistors are often chosen over thermocouples because they are more accurate, have a shorter response time, and are generally cheaper. For most applications, thermistors are the smart and easy selection for temperature sensing below 300 degrees Celsius. In our case, we will be using a Negative Temperature Coefficient (NTC) thermistor, where the resistance decreases as the temperature increases. NTC thermistors are most common in commercial products that operate in the tens of degrees like thermostats, toasters, and even 3-D printers. An NTC 3950 100k thermistor will be used, which is designed for 100kOhm resistance at 25 degrees Celsius. This tutorial will introduce methods for relating resistance to temperature by fitting factory calibration data. The performance of the thermistor will also be evaluated using an Arduino board and a simple Newton’s law of cooling experiment.

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Arduino SoftPot LED Meter (Membrane Potentiometer)

How to use a soft, circular-membrane potentiometer with an Arduino board. Potentiometers function by altering the voltage of a system by mechanically changing the resistance associated with a voltage divider. In a traditional potentiometer (think of turning a volume knob), we are physically changing the voltage of a system. In the case of a soft potentiometer (where the name SoftPot comes from), we are altering the resistance of the voltage divider by physically depressing the potentiometer, thereby changing the resistance at a contact point. The working principle is exactly the same, but in the SoftPot’s case, we are pressing, and for a knob we are rotating.

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Capacitive Touch Sensor with Arduino

Capacitive sensing from human touch. Create a switch without any moving parts with an Arduino board and an inexpensive capacitive touch sensor.

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A Heat Transfer Experiment with Coffee