This week I spent a lot of time working on software. The code was not complete for integration, so I both debugged and added features to get it to the point where it could be tested along with the rest of the project. This included splitting up and reconstructing files, fixing the way boards are identified to use individual names (Black and White, to match their 3d printed parts), increasing usb speed, and much more. The software is now in a state where it works and it can deal with packets with errors, but if there are errors in protocol packets that do not contain any file data, it sometimes fails.
I worked on integration a lot this week. Early in the week, I fully integrated hardware and FPGA firmware with Anju, and demonstrated transmitting data at various speeds at various distances between two boards. This fulfilled our testing for hardware for the most part, and it worked very fast!
During integration, I discovered that when a large number of 1’s are send consecutively, the ambient light filtering loop kicks in and thinks it is ambient light, since the parts we use are designed for laser rangefinders, not communications. To fix this for now, we have disabled ambient light filtering, and the system works. However, we are testing a new way of encoding data where the first half of a bit is data and the second half is 0 to prevent this from happening. This may allow us to keep the light filtering on. I have found experimentally that ambient light filtering is not necessary in most cases, since the board is not facing high intensity green light. Based on preliminary testing, this approach works very well! It limits our speed to 4.167 Mbaud over lasers, but it has zero errors!
I finished our slides this week, which includes having data for most of our tests, and a video demonstrating that we can send files!
Schedule
We are still working on integration. The whole system is now together, and we are working on debugging issues for the next week or two until the demo.
Deliverables
Next week, I will continue working on integration and fixing issues. I will work with Anju to finally select whether we will turn off ambient light filtering or change data encoding to allow filtering to stay. I will also work with Roger on debugging the usb driver, since it fails when reading sometimes, preventing us from transmitting large files.
