This week, I spent much of my time working on the design presentation with my teammates as well as extensively researching the parts that went into that presentation. Of this, I spent most of my time looking over two things: the FPGA pinouts and the camera’s specifications. As discussed by Jullia and in the team status report, we had a major issue with selecting our FPGA. If we used the board from 18-240, we had access to better PLLs, more Logic Elements, and more RAM, but only 40 GPIO pins. The boards from 18-341 had 80 GPIO pins but sacrificed in all other areas. Eventually, we were able to resolve this by looking into a daughter expansion board for the DE2-115 (18-240 board) that I found. The DE2-115 has an expansion slot on the side that can be connected to a number of devices, namely a GPIO expansion board that provides 3 additional GPIO bays. This board can be had relatively inexpensively (~$60, depending on retailer) and gives us all the GPIO pins we need to run our cameras.
Additionally, I also spent much time looking into the OV7670 specifications as that is the camera we decided to use. I searched extensively to find the FOV of the camera as that is required to calculate the size of our studio, however, all I was able to find was a vague reference to 25 degrees with no mention of diagonal, horizontal, or vertical (or vertical from the axis). I was able to find some test images, and judging from these and my photography background my best guess is the FOV is 25 degrees vertically from the horizontal axis. From this, I was able to estimate the size of our studio at around 8 inches by 8 inches, but this is subject to change if the camera’s FOV turns out to be significantly different.