We at the Softwareschneiderei are constantly searching for ways to gather feedback from our projects. We get feedback from our customers and their users, but we also get feedback directly from the code, be it through test results or code analysis. A great way to make your code speak for itself is to provide it some Extreme Feedback Devices (XFD).
Introduci
ng the Smell-O-Mat
One thing we always wanted to have was “code smells” that really smell for themselves. When we ran across an ultrasonic humidifier that can produce room-wide smells by dispensing essential oils, we found the right device for this feedback. We bought two humidifiers and labeled them “good” and “evil”. The hardest part was to find a smell everybody relates to “evil”, but won’t distract you too much from your work. Whenever our code analysis finds a new real code smell, the “evil” humidifier is turned on for some minutes. If an existing code smell is fixed, we get the “good” smell.
The effects
We do not produce code smells all too often. But once in a while, it happens. And this incident can now be perceived throughout the day just by breathing. On the other hand, fixing old smells is a source of refreshing air. Whenever the office atmosphere needs replenishment, all you have to do is to fix some code smells in our large code base (they do get rare!). Of course, most junior developers just open a window for that.
We chose grapefruit being our “good” smell, so our work area tastes mostly limony now instead of just “developer’s thoughts”, a fragrance that yet has to bottled.
The technical solution
Technically, the integration of the two humidifiers with our reporting infrastructure was very easy. Every XFD is controlled by an IRC bot that understands certain commands suitable for the device and hangs around at our central IRC server. As an humidifier only understands “on” and “off”, it could be controlled just like the ONOZ! lamp. We connected the humidifiers to a remote controlled power supply, switched it on and let the bot control the supply.
Our reporting infrastructure forwards its results to an aggregation software that interprets the numbers and produces IRC commands for the device bots. All of this is done with a combination of website scraping (Hudson as our continuous integration server has a wonderful XML API) and IRC messaging.
The history of XFD so far
Over the last years, we gathered XFDs for almost every human sense. We have visual effects, audible feedback using speech synthesis and even bought an USB rocket launcher for forced feedback needs. With the Smell-O-Mat, we can now deal with smelling, too.
The last human sense we have to address is tasting. Plans for the “coffee salter” were impeded by our sense of humanity. We keep searching.
Read more about our Extreme Feedback Devices:
- The Code Flow-O-Meter: https://schneide.wordpress.com/2008/10/06/extreme-feedback-device-xfd-the-code-flow-o-meter/
- The LED Bar: https://schneide.wordpress.com/2008/11/17/spelling-the-feedback-the-led-bar/
- Audio Feedback: https://schneide.wordpress.com/2008/09/04/give-your-project-a-voice/
- The ONOZ! Lamp: https://schneide.wordpress.com/2008/10/27/extreme-feedback-device-xfd-the-onoz-lamp/
Schneide Blog 
Vanilla as an evil smell? Is this a joke? You don’t like vanilla ice cream?
Vanilla ice cream is still tasty, but artificial vanilla scent is evil. You don’t get it out your nose for a long time. Yet, it’s not as cruel as patchouli or other inhuman smells.
We have one too. Ours is called “That build stinks!” and uses a hacked airfreshner.
Did you blog about it already? Sounds very cool. Our devices need very intensive care (refilling, cleaning, etc.) so I would love to hear about low-maintainance alternatives.