Enclosure + Octopod plugin project: Smoke detector?


I am new on this forum and new Octoprint user

Would like to have advises on my project:

My current configuration:
Prusa MK3S + Pi 3 B+ + Octoprint & Octopod plugin
Octopod client on my iPhone to control
All that is working perfectly well together! Amazing system!

Now my project with Enclosure plugin would be to:

  • Command printer supply to stop if needed
  • control led light
  • measure one or two temperature for safety monitoring
  • add a smoke detector (thinking to hack one with a discrete output or something like that... to receive an alarm on my smartphone

First question: is the Enclosure plugin compatible with the Octopod plugin?
Then any advises to do what is described above, in particular for smoke detection?

Thanks a lot for your help


1 Like

You can use the Enclosure plug in to have a smoke detector automatically switch off the printer. First you need to control the power of the printer via a relay via Octoprint. The Enclosure plugin allows you to do things like power down the printer x minutes after a print has finished or is cancelled/failed. Next you need to configure a GPIO input in the Enclosure plugin configuration to respond to a high signal and then activate the power supply control pin you set up earlier. The enclosure plugin allows you to link inputs from a sensor or a switch to gcode OR another output pin. It is very flexible.
You can hack many of the optical smoke detectors to get a fire signal out of them. Many models have a controller chip with the "interconnect" function but most don't use this pin so it's just left disconnected on the pcb. You can attach wires to this pin and the negative of the battery and grab the signal. One example is the CS2105 control chip and pin 7 is the interconnect pin. See: https://www.crmicro.com/Home/product/icdevice/measurement/smoke/201409/t20140902_309410.html
The interconnect signal is active high (to 9v) so it needs to be conditioned (reduced) before connecting it to the gpio pin on the Pi. I recommend using 1K resistor and a 3v3 zenor diode in series across the interconnect and 9v battery ground. Attach the ground and the top (cathode) of the zenor diode to the pi. When the smoke detector is triggered, 3v3 goes to the gpio pin - it is active high. I recommend checking your voltage converter for a 3v3 signal BEFORE you connect it to the Pi. I've done this myself and have an active fire control switch off on my Octopi / Taz 6 setup.