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Project: Do I have my keys? We have chosen to create a device that will remind a person leaving their apartment if they have their keys (or other important items) in their possession. We agreed this this should be a subtle and unobtrusive reminder. In the end, hopefully we can avoid people getting locked out, forgetting a cell phone, etc. Part 1: Observations In designing this device, one of the most important elements is how people interact with their doors. We need to understand this process so we can implement our solution. I came up with a few conclusions that would be important in developing our product. 1. People often leave in a hurry 2. Doorways are different sizes 3. People have a lot of stuff on them already 4. People have small apartments Overall, the basic process of exiting a doorway does not change very much. More important is the environmental factors which make each doorway unique. Part 2: Early prototype This week, our group further discussed how our final device would work and what components we would need to complete the project. After a few field trips in the real and the online worlds, we purchased the major parts needed. These primarily included a sensor, RFID reader and a RFID tag. The sensor will be used to indicate whether the door is open and thus engaging the entire circuit. The RFID components will be used to confirm the location of the keys. If the door is open and your keys (attached to the RFID tag) are not within the range of the RFID reader, then you will be notified by either a LED or tone. Part 3: Ug Our group struggled this week trying to (a) setup the TI RFID chip, (b) understand the communcation protocol, (c) establish serial communcation between a computer and the RFID chip (d) and trying to get/create/modify Processing code to operate the TI chip. Following a schematic provided by TI, we created a breadboard with the TI chip, a MAX232 chip and some LEDs. The MAX232 chip was necessary to enable the RS232 serial and USB connection to the computer. As I understand it, the computer uses 12v and the RFID chip accepts 5v, hence the need for the MAX232. We were able to get the breadboard setup but could never confirm if it actually worked (ie, read our tag) because we could not establish a serial communcation. Thanks to 2nd Year studen Alice, we got some code that would return a reader ID (tag), but it did not seem to correlate to our tag. It seemed to be just sending back our the same tag we sent out. After some assistence from multiple resident researchers, in both software and hardware, we made a descion to use another RFID solution. The TI was very difficult to work woth and probably was more sophisticated than we needed. Resident researcher Doria had a parallax Low frequency RFID reader which we borrowed. With Bryan's programming background, were were able to get some Processing code and talk to the parallax chip. Some non-ITP folks, provided us with code that has some additional functionality. We will look at that to see how it works, but for now we have a basic, working prototype. |