Raspberry Pi Powered Blimp

Bill of Materials (BOM)

Raspberry Pi 3 Model B
- technically any Raspberry Pi will do
- even the Pi Zero will work, as long as you also get a WiFi dongle and USB OTG connector
- NOTE: we had trouble fitting the USB OTG connector into the a WiFi dongle so we don't recommend this approach
Raspberry Pi Camera
comes with cable, so you don't need to separately buy one
Pimoroni Explorer pHAT for Raspberry Pi Zero
two small DC motors
two small (3") propellers
we purchased these from a local hobby store, but they are similar to these from Amazon.com
small 1200mah lithium battery
PowerBoost 1000C
The 1000C is often out of stock, and you can easily use the PowerBoost 500C instead or anything from the PowerBoost family
44" mylar balloon
holds about five cubic feet of helium
9 cubit foot helium tank
WalMart had the lowest cost for the helium, and oddly, the price per cubic foot went UP with the higher capacity tanks

Many suppliers have these parts, but we mostly bought from Adafruit so those are the hyperlinks we are including.

RC Blimp using Raspberry Pi and Explorer pHat

     $ npm install

     $ DEBUG=raspberrypi-blimp:* PORT=3000 sudo npm start

NOTE: the PORT environment variable is optional, but sudo is not (wiring-pi needs it)

node.js v4
- simple RESTful web service that accepts POSTs and DELETEs to /left and /right to independently control the motors
- NOTE: we did not use the old node.js that comes with Raspian
  - to uninstall the old node.js on Raspian, run sudo apt remove nodejs
  - to install a new node.js, follow the instructions on node.js for installation with a package manager
wiring-pi NPM module used for GPIO for the Pimoroni Explorer pHAT for Raspberry Pi Zero
Raspbian Jessie Lite
WebStorm for editing HTML/Javascript

it was much too heavy
recommendations for weight reduction
- use Raspberry Pi Zero instead of Raspberry Pi 3 (saves ~32 grams, as the Pi 3 is ~41g and the Pi Zero is only ~9g. You'll need to add WiFi via a dongle or somehow
use pure helium
- I heard most balloon helium is only 80% pure, but pure helium seems to be pretty hard to find
use a smaller battery
- the small DC motors from Adafruit only use ~30mA IIRC, so even a 500mAh battery will last pretty long and save you precious grams (1200mAh battery is 23g, while the 500mAh battery is only 10.5g.
motors were not powerful enough to really push the whole thing around
- recommendation: use bigger propellers and/or more powerful motors, especially drone motors