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Vibration sensor for espresso machine


jtara92101

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I thought it was high time for an ON-TOPIC post here!  :mrgreen:

 

I have a silly little pet project.

 

I once left my espresso machine on when I left the house, and when I got back it's thermal shutoff had tripped. But I didn't know that, and didn't have espresso for months while I contemplated sending it back to the east coast for an expensive repair. (I had a leak repaired once so had experience...) Eventually, I realized there is a resettable thermal shutoff with a teeny-tiny hidden reset switch, and found the photos online to locate it and - yay - there was nothing wrong with the machine.

 

I decided to use Insteon and ISY to make sure that didn't happen again, enhance safety, and to boot remind me to use the machine when it is ready. If you leave it on too long before pulling the first shot, it will be too hot. 

 

It is a rather manual machine - a spring-loaded manual pull type. ( Requires not much skill for the pull, as you push it down and the spring takes care of pushing the piston at a constant rate. There is some timing to pre-charge the chamber before releasing the lever.)

 

I want to add a vibration sensor now so that ISY knows when I actually pull the shot. It should be:

 

- sensitive enough to pick up the vibration when I pull the shot. That's not hard. The Elfa shelf it's sitting on isn't particularly stable. It will hold the machine, but I don't dare use the knock box! (I do that at the kitchen counter.)

 

- not so sensitive that it will trigger if I happen to grab a cup or saucer or other object sitting on the shelf

 

- ideally, then adjustable sensitivity, or sends a magnitude of vibration to ISY

 

- reasonably unobtrusive

 

- It might be sticky-taped to the back of the machine, or perhaps to the bottom of the shelf

 

I have a Z-wave module in my ISY. I've never used it. I'd meant to use it for a lock at my old place. (So, shoot me Teken...)

 

I don't care if I use Z-wave or Insteon. The machine is 15-20 feet from the ISY, but in next room.

 

I would like recommendations for a vibration sensor. I know there is a CAO tag. But I know there are other alternatives, and looking for the best one for this application.

 

 

----

For amusement only, this is my morning routine. I know the dialog is wordy. It will be shortened. I was showing off!

 

Parts:

 

 - Elektra Micro Casa (espresso machine)

 - Mazzer Mini (grinder)

 - Insteon dual on/off  outlet 2663-222

 - Google Home Assistant

 - watusi/google-cast-public-address.js webservice (nodejs/Express

 - Mac Mini (but will be moving to raspberry pi) to run the above

- ISY with a couple of small programs

- ISY network module

 

Me: Knock puck out of basket, clean machine and basket. Grind espresso if needed, fill basket and assemble.

 

Me: Flip switch on espresso machine to "on".

 

ISY -> public-address -> Google Home: "I see you're going to make some espresso! I'll let you know in a few minutes when your machine is warmed up".

 

(14 minute delay)

 

Google Home: "Your espresso machine is warmed-up, and ready to pull some shots!"

 

me: "Hey Google, I'm making espresso!" (This is the part the vibration sensor is meant to eliminate...)

 

[

    If I fail to do this: (10 minute delay in ISY program)

    Google Home: "You're espresso machine is too hot, so I'm turning the outlet off. You wouldn't want to drink the stuff anyway!"

    ISY: turns off outlet

]

 

Google Home: "Thanks, but espresso gives me the jitters. It's stimulating my olfactory senses, though!"

 

ISY -> public-address -> Google Home: "Remember to turn the machine off when you are done. I'll turn the outlet off in a few minutes, just to make sure you don't burn the place down!"

(works around Google Home response length limitation. There actually was a REASON for the wordiness, I was testing stuff and discovered the limitation, and wanted to develop a work-around technique.)

 

me: make espresso, turn off machine

(concurrently, 10 minute delay in ISY program)

 

ISY: turns off outlet

Google Home: blessed silence. I don't need to know that ISY once again prevented potential disaster.

 

-----

I promise I will publish the Google Cast Public Address piece this weekend, after I give it a once-over for anything else I want to get in to V0.1. Currently, it can send TTS, local MP3s from files, MP3s from network, or MP3 streaming radio stations to any Google Cast device. (It's unpolished for video devices!) It doesn't restore any previous audio source after it is done, but looking at API pretty sure this will be possible in the future.

 

 

 

 

 

 

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I'd think there is a better way to solve this than with a vibration sensor.

 

Maybe replace the top of the handle with an "Open/Close" sensor attached to a mercury tilt switch?

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Yes, I have a home/away scheme.

 

But I am even more keen about not burning the place down while I am home as I am about not burning the place down while I am away.

 

And, yes, the simple solution is a timer circuit. In fact, I think newer models of the machine have one built-in. I could have it retrofitted, or order the parts and do it myself.

 

The biggest advantage is the "ready" timer, which gives me consistency.

 

Let me think about the tilt sensor. Is there something small and wireless?

 

The plastic handle is glued/cemented to a brass shaft, which threads into a chrome(ed) clevis. Something could thread in-between, and hide some wireless sensor inside. It would have to be very compact.

 

I love mercury tilt-switches, actually. I wrote code for one of those crawling LED signs once, a long, long time ago. The case for the sign was asymmetrical, it had a mounting base moulded-in. With the mercury switch added, it could sit on a surface, or be hung from a ceiling, and you didn't have to set some DIP switch to configure the display to invert. The firmware read the status of the mercury tilt-switch, and inverted the pixel buffer as needed.

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If the switch on the machine is an electronic latching circuit, even a short power blink could drop out the ON mode.

 

A Synchrolink, and an OnOff, module could sense and disrupt the power flow to the machine but a little clunky with parts on the cord.

 

A Synchrolink would report you are using it, by sensing current flow, and ISY could allow X minutes and power blink the machine into the Off mode. The Away /Home scheme would only be one logic element for the off logic.

 

An Insteon receptacle and  Synchrolink may be more acceptable but the Synchrolink would be offline most of the time. Maybe a microModule inside the expresso machine.

 

 

Glad I stopped supporting drugs from Columbia, a few years back. I got burned on a few shipments.

 Wait!... It was the coffee that was burnt, until they called it "Dark Roast"  :)

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I promise I will publish the Google Cast Public Address piece this weekend, after I give it a once-over for anything else I want to get in to V0.1. Currently, it can send TTS, local MP3s from files, MP3s from network, or MP3 streaming radio stations to any Google Cast device. (It's unpolished for video devices!) It doesn't restore any previous audio source after it is done, but looking at API pretty sure this will be possible in the future.

*This* I look forward to! :)

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I have a Aeotech Multisensor 6 in my humidor (for measuring temp and humidity).  Every time I open the lid the "Tamper Alarm" value changes to "On".  It doesn't take much movement to trigger the change, and the response time is within a second.  I'll probably replace this with a wireless tag eventually, as the multisensor is too expensive/capable to use for for this simple purpose.

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A Synchrolink would report you are using it, by sensing current flow, and ISY could allow X minutes and power blink the machine into the Off mode. The Away /Home scheme would only be one logic element for the off logic.  An Insteon receptacle and  Synchrolink may be more acceptable but the Synchrolink would be offline most of the time. Maybe a microModule inside the expresso machine.

 

I picked up a Z-Wave on/off module specifically because the ZW075-A02 reports current power usage (watts).   This would allow the same approach with a single plug-in module.

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I agree with KeviNH. There is a lot you can do with devices that monitor power. I use the DSC06106-ZWUS to monitor whether my LED TV is on or off. (No I never fall asleep in front of the TV). Well the TV and cable box never stay on all night long. If the espresso maker uses more power when on, you can tell the ISY to do something when the power dips after creating your favorite beverage.

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I agree with KeviNH. There is a lot you can do with devices that monitor power. I use the DSC06106-ZWUS to monitor whether my LED TV is on or off. (No I never fall asleep in front of the TV). Well the TV and cable box never stay on all night long. If the espresso maker uses more power when on, you can tell the ISY to do something when the power dips after creating your favorite beverage.

 

I don't need to actually monitor power, though.

 

I want the ISY to know if I have operated the lever on the machine. I want to be able to shut off the outlet if I've flipped the switch, it's heated up, and I have walked away and gotten distracted, etc. (If I've left the apartment, that is handled by an "away" program).

 

If it's been too long, and I haven't pulled shots, I will want the machine to cool down. Google Home will let me know that the outlet is being turned off and that I should wait for it to cool down.

 

When I operate the lever, it cancels the ISY timer so that I will not get the announcement about turning the outlet off.

 

As well, once I operate the lever, it starts a timer, and after the timer the outlet is shut off, just in case I forgot to flip the switch on the machine to off.

 

The lever is manual as can be. It loads a spring. There are no microswitch on the lever, and no practical way to unobtrusively add one. I am not adding an exposed microswitch to a polished brass handle! ;)

 

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BTW, the on/off switch on the machine is equally low-tech. It is a simple on/off switch. It interrupts the power to the machine.

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