Today, our group gathered in A406 to prepare the Monday presentation. We already had the overview of our project, the use cases, an idea of the architecture and some technical constraints. The remaining work was to plan the project with PSSC (Project Specific Success Criteria: a testable criteria, with a due date and a member in charge of the task), and to think about the usage of the BLE in our project.
However, it turned out to be more difficult than expected, mostly because the more we thought about our project, the more questions we raised. For example, the BLE is already extremely abstract, and if we want our system to be abstract too, we can’t use the power of BLE. So we will certainly have to build an additional abstraction layer above the BLE stack, so that very different apps can use drops.
Personally, I read a lot of documentation about BLE. It helped me a lot to figure out how the whole stack works (including the subtle but crucial difference between services and profiles). Then, I discussed a lot with Lauriane who has already studied BLE for her presentation yesterday, and we started to think about the additional abstraction layer. We have defined a Message service for accessing the messages (which is basically like a memory bus). We will have to think about the Box service and the drop administration tomorrow. However our main concern is about power consumption: adding an additional layer means that we will need more communication to read or write messages. So we need to keep that in mind!
We also thought about the components we will need. Our system will certainly be very simple, because it is basically a wireless mailbox. So it will require a micro controller, a BLE chip (possibly integrated in the micro controller), a mass storage and the power supply. We also thought about an external interface which would allow the user to plug a sensor (e.g. a thermometer) which would be accessible in a specific box. However we need to think a little more about it, because it would certainly require a lot of work.
Last thing I did today was some consulting for the RoseOnRails group. I discussed a little with Noémie and she explained me that her group wanted to do a little game with the trains in order to make the project more attractive. So we began to brainstorm about this and we came to some great ideas, even if none of them involves Jedi. I let Noemie explain all the details, but just note that it may remind you the good old days of Pacman, Snake, Mario Kart, …
May the force be with you!