Hello,
Question
Which sensor is suitable for detecting whether a turntable is rotating or not? Can this be achieved by a motion sensor or vibration sensor? Which microprocessor would be a good choice to make a battery powered system, which could be placed above my turntable or attached to the dusk protection.
Background
I have an automation which is switching off my HiFi, if no music is playing for some time. The HiFi is quite good, but pretty old, so I connected a Bluetooth Dongle to play music remote from our phones. I am using a smart plug as switch and have an automation which reads our phone sensors to check whether a phone is connected via Bluetooth and if it is currently playing music. So far so good - everything working fine, but now I have a problem where I hope to get an advice:
I am also playing music via a turntable connected to the HiFi now and then. I tried to prevent automatic switching it off when the music is playing via turntable by checking if the power reading from the plug exceeds a certain value (once the turntable is rotating the motor needs some power and my smart plug measures about 1 or 2 W increase in power). My problem is that this is a very inaccurate way to determine if the turntable is playing or not, which is only working if the volume is at a certain level.
Idea
I want to use a sensor connected to something like ESP8266 or 88w8801 to check if the turntable is rotating. The system must be small and battery driven. Unfortunately I do not know a chip that could do this even better using ZigBee - does someone know if a ZigBee ic exists?