Trying to figure out how ultrasonic humidifier detects low water level Answered
I'm currently working on a home automation system and have decided I want to throw my fragrance diffuser into the mix. What I'm trying to accomplish is I'd like the diffuser to come on whenever the unit has power so I can simply control it with a Sonoff SV. I was originally planning on just replacing the guts with an Arduino Nano or something until I tore into it and realized I have absolutely no clue how this thing detects when the water level is low! There's no sort of float switch or resistive fluid detection. In fact, the only part that has contact with the fluid is the ultrasonic transducer. I'm curious if anyone can look at the PCB and give me some more insight as to what's going on. On the far left the five pins coming into the board is the cable connector for the buttons and LEDs, the two large pins beneath that are the buzzer for making beeping noises when buttons are pressed, The SMD IC towards the middle is from what I can tell the brains of the operation. The three large pins (two with solder) near the top center are where 24vdc comes in. The two large pins on the upper right are for the fan and the two large pins on the bottom right are for the transducer. If anyone has any insight as to how this thing reads a low water level it'd be very much appreciated. Thank you!