SiO2 for sure and maybe   GaAs, or GaP, or  GaSaP or InGaN and pleanty of Co2 and H2O

as Tom Carpenter said, the explosion is caused by pressure. Explosions occur when a solid or liquid is rapidly converted to gas. In the case of the LED, I think everything... wire,silicone,plastic, etc becomes volatilized in the energy pulse.

Sorry LMVN, Looks like the MAX6682 has no problem with 5 volt inputs... I was thinking of the MAX6675 which needs 3.3 volts

Also, does the shield you are using drop the voltage from the digital outputs on the Arduino to around 3.3 volts into the 6682?

The manufacturers of the wire would be the best place to get answers. Here is a link that might get you started. As MarkT says, You also need to think about the substrate you will mount the wire on.



http://www.jacobs-online.biz/nichrome/NichromeCalc.html

Seems like an over kill... this guy just used a pancake fan and a pot.

http://www.youtube.com/watch?feature=player_embedded&v=XVLB9c0j1iU#t=8s

If you want to do mostly robotics and you have a $76 budget, I would recommend that you shop around on e-bay and buy JUST what you need. The kit you linked to is for general use and has a lot of stuff you may not want or need for robotics. Even if you did want all of it, you could probably do better buying individual items. Did you read the reviews? They are a little mixed, but generally good... but once again, theses are reviews for a generic kit and if your interests are more on the electronics side than the robotics, then it might be worth it.

 That is a very ambitions first project. You have a lot of cool stuff going on. Congratulations. It  sounds like you put it together pretty quickly also.

 The EZ-Robot kit web site advertizes a Heavy Duty Servo... you might try that. I'm not sure what servos are used in the kit.

So any speed gain going from 8-bit to 4-bit makes no practical gain for human eyes.

Makes sense... but why would virtually all display manufacturers waste so much effort to implement something that has so little payoff?

Did you unplug the shield and try just the Arduino. If so then the next thing to do is buy another atmega chip with boot loader and replace the one you probably fried.

You can't do that. The buzzer robs too much current ( amps) from a LED in series. You will probably have to wire them in parallel and use an external voltage source... if you are not already doing that.

It is not good to hook anything up between the pins and ground without a resistor of some kind.  For an LED probably around 300 ohms is OK. for the buzzer it's hard to say. It might not buzz if you have a resistance in series. The pins might burn out if you push more than 40 or 50 mil-amps through them.

If you are going to do much more than just blink LED's, then you need to learn a little bit of electronics.

Google "Ohms law"  for a start. Also you probably need to buy at least a cheap multimeter to know what is going on in your circuits.

I assume your electrode is a dual electrode that includes both a glass and reference junction.

Practical Makers shield appears to be an amplifier for pH signals. It doesn't give much info on what the output range is but I guess you can adjust it for a 5 volt full range. I tried to look at the PDF file they had but the link was empty... not a good sign.

Developing a instrument amplifier from scratch, is not something you want to do. If you can confirm that the shield will give you a 5 volt output in the pH range you are looking for, I would advise you to use it and get on with the chemistry rather than spending lots of time on the electronics.

oric_dan(333) is correct. If these devices are not "patient connected" you will have far less safety requirements than if they are. In either case you will have to probably deal with testing agencies ( which are expensive ) before you can produce a product for use in a medical facility.

Yeah, I got 10 ATMEGA chips from Mouser in a box almost big enough to put a lap top in... Shipping was paid by the receiver. I also got a couple of Chinese shields packed in an envelope with a wrap of bubble pack with half the pins bent over... Shipping paid by the sender. Oh well...