This week we spent some time working on integration in preparation for our interim demo. We worked on adding to our PCB design as well as coding the LEDs to work in conjunction with the displays based on some hard coded paths and being able to pick the corresponding direction and highlight its matching path. I have also been working on finding the threshold for the smoke sensor that we will use for our fire detection but am still running into issues where different sources have different values but I am determined to get past this block this upcoming week to even see if we are getting accurate smoke readings based on how we wire them up.
One particular step that I am struggling with is figuring out the best plan of action for our PCB design. While Aidan has also been working on our design, we know that this can be applied to the machines in techspark that we had visited last week. However, there does not seem to be resources available besides youtube videos and manuals which have been our research for now. I have also been communicating with Quinn about possible resources as I had mentioned wanting to do in my last status report, and he had mentioned two embedded TAs but after messaging they actually only have experience assembling already fabricating PCBs. Quinn also recommended using JLCPCB in parallel so at least we have a way of getting these PCBs especially after realizing we might be having a 2 layer board. After our interim demo, we also brought up these concerns with Professor Mukherjee and Kaashvi to which we were recommended to reach out to a student of Professor Carley, Brandon Gonzalez, about our options there as he has done research in the area so I plan on reaching out quickly.
For the components that I am working on, I have a testing mechanism that relates to each individual circuit. For example, for the smoke and temperature sensors we have created a threshold of fire in proximity to the sensor itself and we will be able to detect if our node senses this fire or not. For the sake of testing, we would be using a lighter or a candle. For the LEDs circuits, Aidan and I have already tested being able to input different North, East, South, West directions and have the LEDs correspond to those directions. We also tested hardcoding a path based on four nodes and three edges allowing us to output a specified path. This was also highlighted in our display which shows some of our initial integration between working with the ESP32 to both the individual LEDs and also the display. In regards to testing the actual PCBs, that would come with assembling them when they come as we want to make sure that based on our Eagle file that we can replicate the circuits that we have already breadboarded. My components relate to the fire detection use case requirement where we specified that 95% of fires are detected and in order to do so one way to go about it is as we keep testing our nodes by moving a flame towards the sensors, we want to ensure that 95% of the time they are detecting the fire, which currently doesn’t seem to be an issue as we have both temperature and smokes sensors. The other design requirement that my components relate to is the use case requirement that we want to show directions in less than 100s after fire detection. Here this integrated the pathfinding computation with downloading time and the time to display instructions so while this combines separate subcomponents, ideally when testing we could time this to see if we are within our limits.
In the upcoming week, I want to figure out how to get precise smoke sensor readings, wrap up the PCB design and either act on a response from Brandon or send out the PCB design to be fabricated in parallel as well as finalize the rechargeable battery circuit to be able to order the hardware necessary (diodes, resistors, battery holders) as well as figure out how that plays into our PCB design. Furthermore, we would like to continue more steps toward integration especially between pathfinding on Jason’s end so that we can make progress away from just hardcoding paths but paths that actually correspond to smoke and temperature data. With regards to the Gantt chart, we updated it with smaller tasks that need to be done to reach our bigger goals and most notably, we pushed back the PCB component of design and fabrication. With these new edits I am mostly on schedule especially when prioritizing the smoke threshold and using that in conjunction with the temperature sensors so I can test them simultaneously.