# first project - Density Altitude

I want to build an arduino that can calculate the current density altitude.

The minimum information that I need are:

1. Actual pressure (station pressure) in Hg
2. Temperature in Celsius

Would like to output it to a display.

I plan to use the Arduino uno kit but with so many sensors for temperature and barometric pressure I don’t know which one would be best for my first project.

I want to upgrade this project with altitude, angle compass and gps in the future.

help with sensor selection and screen is greatly appreciated at this point.

Go throught the Arduino shield list and search for available shields. It's the easiest way to get started.

"It's the easiest way to get started", maybe if the shields are still available.

Get something like this http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=TP-29-ND Measure the analog voltage it creates with temperature. May need some amplification. Or maybe this http://www.gravitech.us/i2c12ditese.html

Barometer like this, SPI interface. http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=MPL115A1T1CT-ND

http://wahiduddin.net/calc/density_altitude.htm

Good page, from an aviation viewpoint.

You might have a look at this:

markbee

Temp/Humidity

How do you calculate the density altitude from humidity & temperature? ;)

markbee

See reply #3 markbee. Need the other elements also.

Just finished looking over the math and figured out the formulas for calculating Density Altitude.

Here are the information I need to run the math:

Temp Relative Humidity Station Pressure

I do need a humidity sensor. After doing some reading and searching I think I will start with this sensor for humidity

http://www.sparkfun.com/products/10239

and this board for Barometric Pressure and Temperature

Did you make a sketch? I’m wanting to create a small device that can display OAT, Altitude, Field pressure setting inHg and Density Altitude. I know the formula on paper to calculate this but is there a way to make an Arduino do it using a BME280.

Density Altitude = pressure altitude in ft (120x(OAT-ISA temp)

Density Altitude is obtained by setting sea level reading of altimeter to 29.92

OAT is outside air Temp in degrees C

ISA is 15 degrees C plus 2 degrees per 1000 ft above sea level.

The BME 280 can obtain this data, I am just unsure on how to program the math.