We recently picked up one of those Aquasaurs kits for the kids – which lets you hatch and care for some neat little aquatic fish (or shrimp) that date back to pre-historic times. After reading the instructions we got everything set-up and all was good, until we read the part about the temp of the water needing to remain between 72 – 80F. Problem is, we tend to keep our house around 70ish, and during the day, we have our automatic thermostat drop the temp to more frigid temps (to conserve you know!). 
We quickly realized that these things would likely not get past the larvae stage at those temps. For the first two days, we had the tank propped up on the stove under the halogen lights to keep the water warm. However, over time, they would heat the water too much and need to be monitored / turned off for periods of time. We needed to come up with a longer term solution.
One option would be to simply go out and drop $$ (insert cost here – I don’t know) on a aquarium heater – but that would be too easy. I’d rather take my $300+ extra NXT & temperature sensor and make them work for a bit. Now you ask yourself, how the heck would the NXT heat the water. Well, that’s where dSwitch from Dexter Industries comes in. Interestingly enough, the dSwitch did not come to me with the intent of using it to heat the Aquasaurs tank. It was more like irony and good timing that I just received the dSwitch and we got the Aquasaurs going.
Other times, robots are built based on random ideas. This robot is a case of solving a LEGO challenge – specifically, with their Technic 
