Currently, the most significant risk to our project is our ability to accurately determine which items are inside versus near the backpack. To mitigate this risk, we are exploring a new idea of light-based switching of the beacon tags. The concept is that tags inside of the backpack will not be exposed to light (assuming the backpack zipper is closed), whereas a tag next to the backpack would still be exposed to the ambient lighting within the room. Another mitigation we are using is a notification to the user to check that there are no items next to or near the backpack when they are about to leave for an event. By having the user check for such items, the system will not need to be able to distinguish between close to versus inside the backpack.
Another risk we have discovered is that the usage of 4 bluetooth adapters for the scanning process has caused the Raspberry Pi Zero to slow down due to processor overload. To mitigate this risk, we have decided to use only 3 out of the 4 adapters for our scanning process, which will lighten the burden on the RPi Zero. Additionally, we are increasing the timeout update intervals from 500ms to 1s to further reduce the load. Although this increases the time between when a beacon’s signal is lost to when it is removed from the item list, this tradeoff is necessary to ensure that the RPi Zero can still operate without slowing down.
The only changes we’ve made to the existing design of the system involve using 3 rather than 4 adapters for our scanning process, for reasons discussed above.
Our updated schedule can be found here.
A video demo of our interface update from BLE tags can be viewed here.