After being stuck forever because I didn't realize the noise on the 5V line was causing me trouble, things seem to be going much more quickly now. I've now got the code setup to send data to my MQTT broker. I can see it in Home Assistant and in Python's Eclipse Paho client. Next step is calibration (I think I need roughly a +2C adjustment) and then a test from out in the smoker. At that point I'll know that everything up to the point of controlling the fan works.