We decided to build a floating balloon installation with LED lights inside the balloons. Our first step was to make a materials list. First we wanted this thing to float so we needed some helium, second we needed to put the helium into something: balloons, third we needed to attach the balloons to the Arduino: wires, fourth we needed to make it visual: lights (LEDS), finally we needed to power it: 9 volt battery.
So we created our materials list, now what? We had to create our script for the lights. To do this we went to arduino.cc and download the ADE (Arduino development environment). When you open the program on your computer you add the following two functions:
1. void setup(){}
-this function is used as the constructor, here you tell the Arduino what inputs and outputs you want to use.
2. void loop(){}
-this function is the never ending loop, everything you want to happen has to be done here. You can write functions outside of the loop function but they must be called from loop().
Since this isn’t a programming post I will stop all the code talk and skip to the part where *ta da* we have our program and our lights are blinking in a programmed sequence!
Ok so…now what? How to make this thing float? …Balloons!
Our next step was to go buy balloons and fill them with helium. We purchased twelve balloons for a prototype to figure out the weight to balloon ratio, this proved exceedingly difficult because the smallest amount of weight added or taken away altered the balance so severely that the whole thing would either fall to the floor from the former or take off to the sky with the latter! So, after many experiments with just balloons and a bag of objects for weight we finally figured out about how many balloons we would need to make the project float.
Next, we wired and soldered the LED positives to the outputs on the Arduino, while all the LEDs negative leads were soldered to one master negative that went to the Arduino’s ground. This wiring and soldering was by far the most time consuming part of the whole project.
Then we constructed a light weight carrier for the Arduino and the 9 volt battery, this was a simple box made out of a light weight but sturdy material called foam core.
The Next thing to do was to get the lights inside the balloons! This was a two man job, first we put the light inside an un-inflated balloon, then we filled it up with helium a bit, then moved the light further inside so it would be closer to the middle, then while one person pinched the end the other tied it with a cut elastic, then taped it with duct tape. Surprisingly this worked pretty well and we only had one very slow leak.
Once we had all the LEDs inside the balloons we had to start adding “booster” balloons to help float the device. We needed more than the original estimate of 12 because of the added weight from the elastics and duct tape on each LED. This part of the project became a very delicate game of trial and error because we had to keep adding balloons and removing helium until the right balance was found for “floatage”. The final number of balloons needed was around 20.
Once we had it floating the cheers rang out! …and yes we launched it to “final countdown” by Europe!
