https://blog.tindie.com/2019/08/accidental-3d-printer-fires-smoke-detector/
While 3D printers are an exciting technology, in many cases people leave them alone to work on their projects for hours at a time. As is the case with any kind of machinery, there’s an inherent risk of malfunction or fires. However small, it’s important to have something in place to shut down the printer.
The device cuts off power to your printer when a wireless smoke detector senses the presence of smoke or a fire.
Easy to use and operate. Use one transmitter to match more socket receivers or program more than one transmitter to each socket

### How to make it

* things to purchase
1 × remote control power outlet (isolated power supply,10A resettable fuse)
1 × smoke detector (tiny optical)
1 × radio transmitter
If you don't have the mood to build it yourself you can just buy from [Tindie](https://www.tindie.com/products/niujl123/shut-down-printer-by-smoke-alarm/)

### soldering the radio transmitter into detector.
* there is a header which contain 3 pins(G/S/V) on the detector'PCB.
G:negative power supply,
S:Signal output ,
V:positive power supply,

* there are 2 pins to on the radio transmitter (GND/VDD)
VDD:positive power supply,
GND:negative power supply,

soldering the radio transmitter's 'GND'/'VDD' line to detector's 'S'/'V'. when the somke detector senses the smoke or fire,it will set the 'S' voltage from 3.3v to zero,then the 433MHz radio transmitter will work, and send the signal to close the power socket.https://youtu.be/5yT8nklCmxI

### how to pair wireless between power socket and smocke detector? (had paired by default)
1,power on the power socket and smocke detector(2 AAA battery);
2, Press and hold the Power socket's button until the LED flashes;
3, click the button on the smock detector;
4, and then the LED on the Power socket will flash quickly,means it's paired successfully.