Fall break was this week, but that doesn’t mean I did not get some good work in.
I started the week by looking more closely at layer 3. What I wanted to figure out was if the the temperature sensor is necessary or if the one integrated into the pressure sensor is good enough. To do this I just had the two sensors output the temperature and compared them to each other at a range of temperatures. I found that temperature sensor can give more significant figures and responds more quickly to changes in temperature. The data sheet says that the temperature sensor has about ±0.5°C while the pressure sensor only claims ±2°C. This seems realistic from my tests. To decided if I will keep the real temperature sensor I still need to meet with the rest of the team and flesh out how much precision and response is needed by the temperature sensor. Getting rid of if would reduce both the power draw and complexity of the system, which is a definite up side.
Also this week the boards for the new RTC came in. I worked on assembling them and determining an optimal order of operations for assembly. The first one I fully assembled worked, which is always very exciting. I was able to confirm that it is programmable over I2C with a 3.3v Arduino Pro Mini, and that the alarm interrupts seem to be functioning as expected. Now I’m going to assembled two more of them, and go forward with the sharkduino design overhaul with confirmation the new clock circuit is good. A picture of working breakout board is below.