You might want to look into fabric production. One of the oldest automated industries. Spining/weaving/sewing. Do you know what a Jenny and a mule is? How does a shuttle work? Can you implement a PLC that can knot broken threads inside a loom or a sewing machine?
While all this was done as much as 250 years ago. Can it be improved whith what you are currently learning?
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.