Museomix is a short event where coders, designers, hackers, cultural and museum experts brainstorm on collections and museum installations. This document gives hints on setting up an electronic lab so attendees can benefit from real-world interactions.
Often, exhibits must sense their environment (is there light ? is there a visitor ? ...) or act on their environment (turn the light on ! make a sound ! ...).
Don't expect attendees to solder. Most people never used a soldering iron, or juste a few times in school. Since this is not a training session but more like a hackaton, where ideas must come to life as fast as possible, providing arduinos, knobs and resistors just won't work : you'll have to provide technicians for the job.
For the matter, recruiting in the local hacker space of fablab is the best option available. Not only they will know how to solder, but they also have experience in turning their own ideas into reality and have experience in simple electronic design.
From past editions, approximately half of the teams need varying levels of electronic design and soldering. This can be a simple button that lights a LED, to a complex array of LED, sensors, remote controlled vehicles, ...
So it is better if the organization can provide one hacker per team (i.e. 5 hackers for 10 teams). Another option is to have hackers as attendees, and let them integrate teams during the "team-mating"/recruitement process.
Soldering should occur in a open, well ventilated spaces, away from dining areas. Fumes (especially with lead-free soldering) can be very irritating. Workbench must be clear and big enough, and away from the crowd. Soldering irons are quite pointy and pretty hot...
There must be one soldering station per technician. Soldering a project can involve a lot of metal melting and time is limited for everyone. Stations are preferred over simple irons because or their physical stability and their ability to control temperature precisely.
A development platform
The best choice here is probably an Arduino kit with a ProtoShield and a breadboard. This let hackers quickly test their design on the breadboard and solder required components on the prototype shield when the design has been tested. they come with a handy LDR (Light Dependent Resistor)
One complete development platform for 4 teams seems a good ratio.
Starter kits can provide a good collection of sensors and actuators to add to development platforms. They are often targeted at specific platforms. Arduino being the most proeminent, kits from SeedStudio (like Groove - Toy Kit or Groove-Started Kit) should be considered. Having a pair of each kit at reach would probably be useful.
Other sensors and actuators should be acquired separately.
Must have sensors include PIR motion detectors and ultrasound rangefinders. They can sense if someone is present or moving in the measurement field. They let designers act on visitors presence.
Another category is the LDR, a chreap sensors that can "measure" ambient light levels. They also can be used as cheap presence or object sensors (when someone or something is blocking light for instance).
Buttons have often been used in exhibits involving mechanical parts (miniatures depicting antique machines, wheels, etc...) and must be in the parts grab bag.
LEDs are sometimes used to interact with users. However, it's not easy to have the proper samples (colors, number of items). It is advised to have a few samples of each color (red, green, blue, white, amber, ...), and a large batch of the same color if a team needs to make a LED array.
Sound players are among the most frequent requested items : some teams do not want or need to deploy a full multimedia system (e.g. a PC) but would be fine with a single sound player activated by some sensor (like a PIR sensor). In this case, Arduino sound shields or extension can be used. Several options exists in this area. A pure shield like Adafruit's Wave Shield, or integrated devices like FTDI's VMusic2.
Another way to go is to use an inexpensive RaspberryPi for sound play. While a RaspberryPi is somewhat overkill for the task, it is cheaper than an Arduino + Sound shield, and offers some new horizons.
Voltage controlled light dimmers have been used a few times (like the Botex UP-2RF) This model accepts voltage input between 0v - 2.5v and will dim light between 0 and 100%. This dimmer works with usual show lighting gear.
A grab bag of resistors, capacitors, voltage regulators, diodes, zener diodes, transistors should be provided. A pile of variable resistors, connectors, and miscellaneous parts is highly desirable. It is pretty hard to know in advance what you'll need, so it's probably best to bring as much small parts as possible.
A digital multimeter is a must have in this context (one for the whole lab should be enough). Sometimes, problems are tricky enough and can not be tracked down with a DMM (multimeter). A digital oscilloscope can save the day in this case. Some small portable oscilloscopes like the DSO Nano are good enough for this job.
If wireless communications are required, Snap modules can come handy. They are relatively cheap easy to deploy provided you purchase the proper boards along (at least an USB dongle on the PC side, and a shield on the Arduino side. The Snap modules can be programmed in python so when the infrastructure is up, programs can be deployed in a... snap.
Providing a successfull electronic lab in museomix-like events can be summarized in these items :
- have a dedicated electronic/soldering team, one hacker per team for consistency and equity
- have a grabbag of components, and let the hackers bring their own usual tools and parts
- have many development paltforms handy
- focus on light, motion and presence sensors; have a few switches/buttons too
Starting an electronic lab is not an easy task. Event to start small project, a lot of parts are required. Thus, for a short event like museomix, it might be wise to team with the local fablab to get the proper tools and acessories.