I'd love to see youngsters playing with Arduinos in schools.
I envision a "box" with....
USB connector (for connecting Arduino inside box to "big" computer, for various things)
Several "type X" connectors into which a carefully restricted range of robust sensors and switches could be plugged
Several "type Y" connectors which would allow a range of output devices (LEDs, Buzzers) to be plugged in.
("type X"/ "type Y"... I'm not talking about any specific range of connectors here... just trying to indicate that the users would not be able to plug a sensor into a socket dedicated to being an output from the Arduino)
Now... IF (and it is discussion for a DIFFERENT thread!) you could "knobble" the compiler's pinMode command, so that the pins of the Arduino were "permanently" (within the environment of the project) be "pre-programmed" as inputs or outputs, can you think of ways a user could damage the "box"?
(Also, please, with respect, for OTHER threads: "Why would you want such a box?", etc!)
(And yes, the "box" would probably carry a momentary switch or LED or two, in addition to the sockets for plugging in other goodies. Details! Is the "box", in general viable? It needs to be "indestructible", before schools can be persuaded to invest.)
Marketing: Anyone see anything wrong with "Rugguino" as a name for it? ("Rugged Arduino"... and if anyone wants to think "Arduino for rug rats", I'm not going to blush.) To Italian speakers, does it sound like something unfortunate?
can you think of ways a user could damage the "box"?
Now you are just asking for it on this forum aren't you.
There will always be ways of damaging inputs and outputs with excess input voltages reverse currents, mains input, RF inputs and so on. You can protect to a certain extent but these things can't be made student proof.
asking for it
... tee hee... yes!
I had in mind that the students could be persuaded to ONLY plug in things provided to them from a drawer of "known safe" "peripherals". So, for instance, if they were being given access to a relay, there would be a diode across the coil of the "relay peripheral" supplied with "the box".
The students wouldn't be using breadboards, etc, to break out the signals coming from/ going to the sockets on "the box".
(PS: And the "things" that can be plugged in, would, by their physical connectors, be resticted so that things that should be plugged into an input can only be plugged into an input, and outputs to outputs.)
Perhaps different connectors for the inputs vs the output? Was going to suggest 3.5mm headphone jacks + 2.5mm headphone jacks but Mike's warning are ringing in my ears....
There used to be a product called SMART box for logicator which was designed for students to make it easy to build devices and plug in sensors/lights/buzzers etc. It was basically to teach about control systems but they can't have done too well with it as it does not appear that you can purchase them any more (or have been able to for quite some years)
I presume it used a PIC chip internally as it was controlled by logicator, possibly with some internal protection but the main idea was to plug ready made compatible sensors etc into it so the risk of blowing it up was minimised.
I'm not sure how well this would work now with an arduino. Depends how the input/output devices were implemented.
I think something like this (presumably designed for this purpose) is the closest so far:
There is a rugged acrylic cased one with screw terminals too but I can't find it now (they obviously need to work a bit on website meta tags)
There is always this one as a starting point: --> RUGGED CIRCUITS http://www.ruggedcircuits.com/html/mb324p.html
Neat products... particularly like the clever use of the perspex mask on the RuggedCircuits unit...
But still inspired to work on my Rugguino... products listed seem a little complex for my target audience, who might be able to plug in, say, two switches, two LEDs, and "play" with what the switches do in response to switch closures.... but not be "clever" enough to be trusted with "naked wires" with 5v, etc. Would hate, for instance, to see what would happen if the 5v line of either board were connected to a pin configured as output, and set to output "0". Etc.
Please re-check original question? What can go wrong, if WHAT can be plugged in, WHERE, is reasonably under control, and pins cannot be reprogrammed to make pins intended to be inputs into outputs.? (And, though not as critical(?), vice versa).
This product might be of interest to you:
It's compatible with Phidgets - www.phidgets.com