I don't see what you narrowed it down too. Was it from switching the audio path? Was it the generated waveform? Was an offset in the waveform? Was it the external circuit? Did you change from the default CODEC bias? Did you get a startup glitch from turning on an amplifier? Did you forget to soft switch the CODEC? Was it digital crosstalk from the data path? I can go on.
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.