There are lots of ways to get your projects airborne – we’ve looked at two options in past cover features: drones and rockets. However, there’s a less common, more calm, and controlled option: blimps. These use a lighter-than-air gas (typically helium) in a balloon to lift the weight, then use several small motors driving fans to manoeuvre the aircraft around. Since there’s no weight to lift (the blimp should be neutrally buoyant so neither fall nor ascend when floating free in the air), these motors don’t have to be particularly powerful, and so a blimp needs much less power than most aircraft.
The downside of this setup is that it’s much slower and much more susceptible to wind. The Blimpduino 2 is, as the name suggests, an Arduino-compatible blimp. All the electronic functions are packed onto one board, which has an ARM Cortex-M0, accelerometer, LiPo charging port, and lidar. Additionally, the kit comes withthree motors with propellers. You can also order a 3D-printed gondola ($9.12) if you don’t have a 3D printer, a LiPo battery ($7.81), and a helium balloon (from $5). The only thing JJRobots doesn’t supply is the helium, which you should be able to source from local party shops.
JJRobots recommends that its blimp be flown inside. Although the hardware should continue to work upwards for quite some distance (until the air pressure changes enough to stop the helium lifting enough weight), the lidar distance sensor is only accurate to four metres.
Although the blimp is Arduino-compatible, this isn’t actually relevant for the basic operation. Once the hardware’s connected up and powered on, you can control it via a phone app. This gives you basic controls for flying. We found that the app didn’t work properly on the first phone we tested (there’s a thread about this on the forums).
However, we were able to get it working on another phone. This gives you a basic, WiFi-controlled remote. You can steer the blimp, and take it up and down. These controls aren’t simply connected to the motor output: there is enough intelligence in the Blimpduino 2 to compare your instructions to the received data from the accelerometer and lidar so it will behave intelligently, not just spin out of control.
‘Attempt’ is an important word here as it’s limited by the hardware as to how effective it will be. For example, if your balloon is poorly balanced, it might not be able to ascend and descend properly.
It’s a little hard to give good estimates of how long it will fly for, as the amount of energy it has to expend depends so much on how you fly it. In ideal conditions, it should be able to hold its altitude without expending any energy, so could hover indefinitely. However, you’re probably going to be moving it around. We found we got about 20–30 minutes from a 500 mAh battery between recharges, but you may find you get different results.
If you want to go further, the firmware behind the device is written in Arduino C++, and the programming port is open, so you can add whatever extra features you like, whether that’s some form of autopilot or additional sensors. You can add more weight without it being a burden on the motors, provided you’ve got enough lift capacity in your balloons. You can add larger (more) balloons, but this will eventually slow down your blimp and make it harder to control.
While there aren’t any specific guides to modifying the hardware or software, the source code (available here) is commented and reasonably straightforward to follow. Perhaps the most unusual part of it is that the default app communicates via UDP, rather than the more common TCP. This isn’t particularly hard to use, but it’s less likely to be familiar to users. There is no need to stick with this communication method – you’ve got full control of the hardware, and can communicate with it however you like. The only slight issue is that you don’t have access to the programming port on the ESP8266 used for WiFi, so you’ll need to be familiar with the commands for this if you want to modify the wireless setup.
We really enjoyed how adaptable the Blimpduino 2 is. In its most basic use, it’s a remote-controlled blimp (some assembly required). You can switch out the balloon and 3D-print replacement parts if you need, and you don’t need any particular technical skills to get to this level. However, if you like to tinker with things, it’s easy to dive further in, and everything’s accessible to you. You can add other things that don’t require programming, such as an off-the-shelf FPV camera/transmitter module (these just need power and will transmit automatically without programming). If you do want to go further, there is the hardware to support it.
Verdict: 8 out of 10
A fun flying machine, suitable for all ages.