These past two weeks, since I missed a weekly update last week, a lot of work was done. I first identified that our thermal sensor, which had been ordered earlier this semester, can only communicate between I2C and has a specific header that needs purchasing, as well as a logic level converter. I talked to Tamal and made a contingency plan of ordering a breakout cable and level converter needed, with the understanding that the thermal sensor will not be a part of our interim demo.
I then soldered male header rows onto both of the regulator boards and built the hardware for the interim demo. A completed picture of the hardware can be seen below!
The battery runs into a 3.7V to 5V boosting regulator (which doubles as a charging board). That 5V powers both the ESP8266 dev board (which powers the processor and wi-fi module) and the PIR sensor. During the demo, the PIR sensor was taped to the bottom of a table, however the idea is to eventually mount the entire system under a table so it is out of the user’s way. After further testing, I determined that we did not need the 5V to 3.3V buck regulator, since the dev board steps down voltage levels internally.
Finally, we completed our interim demo! I think that it went well overall, and we were able to take a reading from the PIR sensor and send it all the way to a mocked up version of the web app. My major next steps involve integrating the thermal sensor into the rest of the design both hardware- and software-wise, now that the parts have come in, and finally doing some battery testing and work on power saving to round out the end of the semester, and I am currently on schedule to finish that out.