Making a height sensor to measure my Kids height

Hey guys,

I am relatively new to Arduino (I have had a couple of boards for a while, but am just now really trying to explore with them)

I had an idea that I mostly understand how to do it, but I am having trouble.

My Son and I go to the local National Science and History Museum fairly often, in the Children's section and they had a tall Giraffe, that when you stood under its head, it would talk to you and tell you your height. I looked up, and it was a Paralax Ping))) sensor they used. I figured I could make this.

So that is my goal, to have a Ping sensor above, and have it display height, probably through a 7segment display or something of the like.

What I have so far:

Running an UNO, with the Ping))) sensor off of the example Ping Sketch, It currently CONSTANTLY shows ping distance in inches and centimeters in the serial monitor.

The device will be installed at a known height, so what I WANT it to do is: 1.Press Button to activate 2.Measure Result 3. Display RESULT(Minus) Known Height = Object Height Displayed hopefully in feet and inches (i.e. 3 feet 4 inches)

So the main things that I need help on: Adding the proper math to the sketch (confusing me a little) Adding the push button to activate the program Out putting the proper information to the display

So, pretty much all of it I need help on.. :) I am about to go research segment displays and see if it is possible to do what I want with one. And going to try to learn button command.

Also open to suggestions.

The goal is to install this in my Mothers house, She has a wall that she measures every family member since I was a little kid, and I would like her to be able to measure my son, and everyone else with ease, and accuracy.

Thanks for the help!

Actually an LCD display I think would work better than a 7 segment.

Adding the proper math to the sketch

Start off working in inches. Put in the install height in inches as a constant then the person's height is just

PersonHeight=InstallHeight-PingReadingInInches;

Adding the push button to activate the program

Use digitalRead. Use the internal pull-ups to avoid the need for your own pull-up resistor

Out putting the proper information to the display

How about using an LCD, then you can print the results using the LiquidCrystal Library