How to compile a C++11 app on Travis CI

I have recently been adding Travis CI builds to code that I host on GitHub, so that I don’t need to host my own build infrastructure.

To users, this just means that there is a green badge at the top of the README, but not much else:


To build a simple C++ project, I added in this .travis.yml file:

langauge: cpp
sudo: false

      - libusb-1.0-0-dev

  - make

Unfortunately, on this infrastructure, the default build tools are currently ancient, and installed on Ubuntu Precise (12.04):

$ make
g++ src/missile.cpp examples/basic-sync/basic-sync.cpp -o bin/basic-sync -lpthread -lusb-1.0 -std=c++11 -Wall
cc1plus: error: unrecognized command line option ‘-std=c++11’
cc1plus: error: unrecognized command line option ‘-std=c++11’

Option 1: Update the toolchain

There is some structures you can use to install an extra repository and some named packages, instead of using apt-get directly.

langauge: cpp
sudo: false

    - ubuntu-toolchain-r-test
    - gcc-4.8
    - g++-4.8
    - libusb-1.0-0-dev

  - make

Because the old version was still installed, I had to refer to the exact version in the Makefile, as in:

g++-4.8 src/missile.cpp examples/basic-sync/basic-sync.cpp -o bin/basic-sync -lpthread -lusb-1.0 -std=c++11 -Wall

Option 2: Update the platform

You can also change to a more recent Ubuntu distribution. Presumably Ubuntu Precise is only the default because existing builds use it.

If you need to build C++11 apps on Travis CI, then builds will work under Ubuntu Trusty (14.04), which happens to be the newest distribution currently available:

langauge: cpp
sudo: required
dist: trusty

      - libusb-1.0-0-dev

  - make

Missile Launcher on Raspberry Pi

This post covers a few setups to experiment with if you have a DreamCheeky USB missile launcher and a Raspberry Pi.

A newer version is being sold on ThinkGeek, but the one I used was:

DreamCheeky USB Missile Launcher

Setup 1: Direct to PC

The launcher comes with some software to let you connect it straight to a computer. Of course, USB can only go 5 metres, which is not much fun for cubicle warfare:

USB Missile Launcher setup with PC

I included this setup because it is the easiest way for Debian/Ubuntu users to test that they can use this driver, which is needed for the other setups.

Setup 2: Networked with Raspberry Pi

So for this setup, you need a Raspberry Pi Model B. They look like this:

Raspberry Pi Model B

Running Raspbian, upgrade to Debian Jessie, and compile the code:

apt-get install git libusb-1.0-0-dev libncurses-dev gcc g++
git clone --recursive
cd missile

You can then place the pi anywhere with network and power:

USB Missile launcher setup with Raspberry Pi

To operate the launcher remotely, use SSH to log in, and run missile/bin/keyboard-ctl.

Setup 3: Wireless with Raspberry Pi and Battery

Of course, network and power can be provided with a power bank and wifi adapter:

Power Bank for mobile phone
USB WiFi Adapter

The wifi adapter will take some work to set up (see Debian Wiki), so I wont document that here. You will need a power bank that has enough power for the Raspberry Pi with launcher and wifi. Mine had to be close to fully charged to work.

An obligatory diagram of this setup:

USB Missile launcher setup with Raspberry Pi (WiFi and Battery)


The reason this helps with cubicle warfare is simple: The launcher, Raspberry Pi and battery can be fitted into a tissue box or other small space. Proof:

Box interior

On a desk you would see this as:

Box exterior
Box open

And a quick demo for completeness:

In the above, the Pi is connected to DC power, because the battery didn’t have enough juice to power the unit.

USB Missile Launcher

Back in February I coded up a userspace driver to control a USB missile launcher manufactured by DreamCheeky. The video below shows one of the example programs in action.


The code being executed in the video is from basic-sync.cpp, the simplest demonstration I could think of:

Missile *launcher = new Missile(launcherHandle);

launcher -> async = false;
launcher -> move(ML_DOWN, 1000);
launcher -> move(ML_UP, 1000);
launcher -> move(ML_LEFT, 1000);
launcher -> move(ML_RIGHT, 1000);
launcher -> fire();

delete launcher;

The USB driver uses libusb, and was coded in response to this trivial bug not being fixed in the Ubuntu repositories for over a year.