I’ve been diving into the world of MQTT sensors and automation in Home Assistant, and it’s been a fascinating journey! 
Let me share some of my experiences and insights with you all.
First off, I’ve been experimenting with a binary MQTT sensor that’s designed to go into deep sleep mode. It’s a self-made PIR sensor with an AM312 on battery power, and it only sends “on” commands. To handle the absence of “off” signals, I’ve been using the delay_off function in Home Assistant. While this works, I’ve encountered a couple of minor issues that I’d love to get some feedback on.
One challenge I’ve faced is the requirement for an availability topic. Since my sensor is mostly in sleep mode, I haven’t implemented one. Instead, I’ve been manually activating it by sending an “online” message with the retain option. It’s functional, but it feels a bit hacky. I’m curious if there’s a more seamless solution within HA to handle this scenario without relying on manual intervention.
Another thing I’ve noticed is that after a reboot, the sensor goes to the “on” state initially and then turns off after the delay_off period. This means my lights would temporarily switch on after a reboot, which is both amusing and a bit inconvenient. I’m wondering if there’s a way to ensure the sensor starts in the “off” state post-reboot to avoid this brief light activation.
Moving on to a different topic, I’ve also been exploring how Home Assistant handles naming conventions for entities. For instance, I have an entity named switch.bathroom_small_ventilator, which appears as “bathroom_small_ventilator” on my dashboard. While it’s functional, I’d love to translate it into another language and give it a more user-friendly name. I’m curious if there’s a way to achieve this without disrupting the automation references tied to the entity ID.
In my setup, I’ve been using MQTT to control various devices, and it’s been a breeze integrating them into my smart home ecosystem. However, I’ve also come across some hurdles, like ensuring smooth communication between devices and maintaining consistent performance. It’s been a learning experience, but the satisfaction of seeing everything work seamlessly is truly rewarding!
If anyone has tips or tricks for optimizing MQTT sensor setups or enhancing entity naming conventions, I’d love to hear them. Let’s continue to explore and innovate together in the world of smart home automation! 
Best regards,
Matt