My group and I are working on the SmartShelf, a prototype for helping dieters stick to their diets.
The system is going to use magnets to provide users hepatic feedback when removing certain items from the shelf/fridge and give them a reminder which foods are not on their diet.
We started be experimenting with electromagnets. We want to be able to control the magnets using the handyboard
so that we can programmatically control how much magnetism each container gets. Our first challenge was to wire this up in such a way that it would work correct. We quickly found that the handyboard did not provide enough juice to really power the magnets as necessary. We then turned to an external power source, but we had trouble wiring the setup in such a way that we could control the strength of the magnets. After some research we found our handmade magnets too weak to get the job done. We ended up buying magnets from an external supplier. The magnets purchased were strong enough but we still were having lots of trouble wiring the system to give us variable resistance. We tired using resistors and potentiometers, but nothing seemed to give us the control and variable strength we needed.
One comment I would make for future classes is to not think so much out of the box on this project. I understand that thinking out of the box helps foster creative ideas, but thinking about the technologies we had to implement this project a little more would have kept us from trying to implement ideas that were too far out of our range. I am disappointed that we were asked not to worry about the technologies when first looking at ideas for TUI's. It personally caused a lot of frustration when we were having such a hard time implementing the variable resistance.
After lots of frustration we were able to wire some relays to an external power source and the handyboard to generate the variable resistance we needed for the magnets. Once we were able to get this going we started to implement the RFID section of this system. We decided to use RFID to sense which items entered and left the shelf/fridge so that we can control the magnets on the fly based on which items were in each container. This section was fairly straight forward. RFID setup was the hardest part to get right. Making sure all the classpaths are set correctly is the biggest challenge, but once this was set, most of the RFID section was fairly easy.
Our final problem to battle was the interaction between the handyboard and RFID. We had no drivers that would help us communicate between the two systems. After researching online we were not able to find much help. We did however come up with a way to communicate between the two. We decided to use java robot class to issue keyboard and mouse clicks to the handyboards interactive mode. This allowed us to mimic someone typing on the keyboard the commands we would need when items entered and left the shelf/fridge.
We are now working on putting the finishing touches onto the system. More updates to come...