Normally DIY cat feeders uses simple dispenser. This works great, but it is hard to predict the amount of food that drops in to dish. Mgrenonville started with dispenser based feeder and now introduces second version which is more controllable and predictable. The feeder is controlled by Arduino with proto-shield attached. Time is kept using DS1307 RTC board. And feeder is run with screwdriver motor.

There is also an LCD screen where status can be seen. A serial interface is used to modify settings like time, number of feeds and other. Most fun part in this is screw feeder. It is made of Poly-morph which has low melting temperature and is fairly easy to work with. Feeder seems to work pretty smooth and is well blended above cat dish.

Robotic hand is one of most important parts in robot equipment. This is main manipulator that interacts with outside world. Complex robotic hand may be very expensive part that may be hardly achievable by hobbyist. Anyway you are always free to experiment and find new ways of reducing cost while making it worth using. Aaron Thomen have been experimenting with interesting robotic Arm solution controlled by Arduino.

As you can see. Few smart approaches makes it really responsive and realistic enough. It is basically made using servo motors and spring-loaded fingers. Fingers are maid of bicycle chains that have many joints and are really flexible. Servo motors activate finger by pulling strings. It is able to pick small objects pretty well what makes it great candidate in many awesome projects. So this is an example of how complex things can be done simple way.

There are many ways of putting real world data to webserver. You can use third party services like cosm. But if you do like to keep everything under your control then do it simple way. Luca chares a tutorial how to do this using simple PUT and GET methods. For this he uses PHP pages to read data from Arduino with Ethernet shield and then display on webpage in your desired form.

His example is based on reading SD18B20 temperature sensor. Data is stored in CSV file, but it is recommended to use database instead. But for demonstration purposes it is enough.

Well, if you ask what is common between Arduino, BeagleBone and Raspberry Pi, I’d say they are pretty popular in hobby market. Roger Meike has made an interesting comparison between those development platforms some time ago. We could argue that there could be more boards in the comparison list, but these are already interesting to look through.

The fact is that all three platforms are pretty mush same size (about 2”x3”). Each of them has their own benefits and shortcomings. No argue that Raspberry Pi and BeagleBone leave Arduino far behind in terms of performance, memory and connectivity.  Beagle bone is a bit pricy but has an analog input what we miss in Raspberry Pi. I would say this is a bit unfair comparison, but pretty interesting read. Who knows – maybe someone will find this a useful as a selection guide of next platform.