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.

raspberrypi-blimp

RC Blimp using Raspberry Pi and Explorer pHat

Instructions

• install dependencies:

     $ npm install

• run the Node.js app:

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

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

Software Design

• 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

Photos and Screenshots

After-Action Review (AAR)

• 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