If you work outdoors, making an automatic temperature sensor for the winter season could be beneficial in the long run

 

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Colder weather is fast
approaching, which means keeping a careful eye on your body temperature if you
spend a lot of time outdoors. Winter’s risks toward your body include frostbite
and even hypothermia if your temperature falls too low. To find a solution to
those chilly days of yardwork or outdoor exercise, Makezine user Jason Poel
Smith designed an automatic
temperature sensor
that monitors the warmth of your fingers, toes, and
torso in relation to the day’s temperature. Try following his steps, shown
below, to make your own temperature sensor before the coldest days of the year
come around.

 

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While there are various different
sensors you could use for this project, Smith incorporated a TMP36 integrated
circuit because of its linear output and ability to work without any
calibration. Having transistors with differently sized emitter layers, the
sensor ultimately has different outputs at different temperatures, and you can
determine a certain temperature by comparing the sensors. This particular
sensor also has an operating range of –40°C to 125°C, giving you usage in even
the most extreme temperatures. Smith also shared an Instructable
link
for specifics on how to use the TMP36 sensor.

 

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After determining what type of
sensor to use, you can add connector wires to the leads of your sensor. Since
the finalized sensor will be mounted several feet away from your
microcontroller, you’ll need to connect the sensor with these wires. Smith used
header pin connector cables, cutting one end off the cable and fusing three
wires to the sensors’ leads.

 

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Next, in order for the
temperature sensor to measure finger and toe warmth, you’ll want to place the
sensors inside pairs of gloves and shoes. Smith recommends using gloves with
multiple layers for secure mounting. When you’ve selected an ideal pair of gloves,
cut a slit in the inside cuff’s fabric lining and then slide the sensor and its
wire between the liner and the glove’s next layer. Situate the sensor by the
end of the middle finger’s space. When mounting a sensor inside a shoe, no
modification should be needed, and just sliding it into place should do the
trick!

 

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The
next challenge is to connect sensors to the Arduino. Smith’s TMP36 sensor can
connect directly to Arduino pins, and he advises that the sensor’s left pin be
connected to the Arduino’s 5-V pin/3.3-V pin and the right one be connected to
the GND pin. The Arduino’s center pin can connect to one of the board’s analog
input pins.

You’ll
then need a second set of connector wires to fit between the Arduino and the
original wires found on the gloves and shoes. As with the original fitting,
these wires should also fit between layers without an issue.

 

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Because
the system needs to alert you when your body is growing too cold, you should
invest in earbud headphones to include in the device setup. Smith was able to
connect headphones to his Arduino’s pins by adding a headphone connector and
soldering on an extension wire and 100-kΩ resistor. The resistor is needed to
adjust the tone that PWM output pins will play on headphones.

 

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Next,
download the Arduino code
and upload it to the device.

 

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Your
next task is to track down an insulated project enclosure large enough to hold
the Arduino and your 9-V battery. After drilling holes in one side of the
enclosure for the headphone connector and wires, position everything and seal
the enclosure.

 

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Now
your sensor should be totally prepared for use in cold weather. The Arduino
board is capable of working with six sensors at once, so Smith recommends that
you make even more so you’re thorough in regulating your body temperature. If
any sensors reach below your set alarm value established in the Arduino code,
you’ll hear a tone in your earbuds to fix the technical issue.

 

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Since
the colder weather will be here before we know it, looking into making your own
temperature sensor is definitely a smart idea.

Source: Makezine