Off Topic (for now) Prototype

[karbomusic]

This is actually the very beginnings of a new stompbox and the first step is to get my toes wet by designing a laser matrix alarm (using mirrors) to keep my cat from sneaking downstairs at night. This is a prototype of the "Catnip Tripwire Laser Defense System" I dug out my old "vaper" to make vapor to show the beam and demonstrate just how sensitive it can be set....

Etched a prototype PCB and tried some liquid tin, neat stuff...





I have a bunch of hobby mirrors on the way so I can create the matrix. Basically it'll be in a box with both the laser and the LDR. The laser will be bounced around the "protected zone" finally reentering the box hitting the LDR. If the beam is broken anywhere, the alarm sounds.

[deadastronaut]

neato....

[garcho]

New switching system for your TS?     Bravo

[karbomusic]

New switching system for your TS?     Bravo

More like a laser harp but for a guitar pedal fun.

[garcho]

YES   looking forward to seeing/hearing it. Lots of applications coming to mind...

[samhay]

what colour and how powerful is that diode laser?

[R.G.]

I have a concept pedal on the work bench, back amid the composting rubble, that I call the "Smoking Gun".

It's an e-cigarette guts, a one-shot timer with some other electronics, a white LED and a small air pump. When you stomp the pedal it sends out a time-able puff of vapor/smoke, and illuminates it according to several settings with the white LED.

When you stomp in a good lead setting, your pedalboard *should* emit smoke.   

[karbomusic]

what colour and how powerful is that diode laser?

Red single color pointer style. This one's from an Arduino kit but I have 20 others on order that should arrive soon. I'll probably use 3-6 of them depending. It's as powerful as a laser pointer, goes far, not hot. I'm currently working out (in my head) the axis and params I can and want to emulate. It wouldn't be out of scope to end up going in several directions since it could end up going the analog and/or digital route such as firing off MIDI commands. Arduinos are cool like that. Current operation for the kitty alarm is...

LDR is 1/2 of a voltage divider with the center of the divider going to an analog read pin. The read operation has a configurable threshold which if exceeded fires off the alarm code which runs a predetermined amount of time. With all those analog and digital pins + coding possibilities one could dream up a lot of cool stuff.

^I originally did most of this using a TL071 set up as an oscillator and a transistor switching mechanism so that the LDR fired off the oscillator. That was fun but a little too limited as far as speed of development/R&D was concerned. Plus with this, I can program it and change features after the device is constructed.

[Joe Kramer]

It's a great way to help your kitty stop smoking.  

Nice work there, Mr. Karbo!

[karbomusic]

It's a great way to help your kitty stop smoking.  

Nice work there, Mr. Karbo!

Joe! You need more posts here, you have too much to offer! Side note: The package with the PCBs to etch etc. shows "out for delivery" so I should have them today. Can't wait!

[mth5044]

Neato. So light is blocked, LDR goes high, chip pin reads on (or off, depending how your voltage divider goes), starts buzzing. I have to wonder though - wouldn't a gate just keep the cat out? Does the alarm scare the cat and make it not go down, or are you just awakened by an alarm and still have to get up on the middle of the night and remove the cat?

[karbomusic]

wouldn't a gate just keep the cat out? Does the alarm scare the cat and make it not go down, or are you just awakened by an alarm and still have to get up on the middle of the night and remove the cat?

Cats are basically tiny acrobats, she'd just jump it while snickering at my futile attempt. It's not that loud and her safe zone is upstairs. When she sneaks down, she is on high alert. AKA she never comes down when anyone is up and about so even this small alarm that I would never hear from the bedroom will invoke the "Runaway, runaway as fast as you can" response back to her safe zone. She could and may figure it all out but in the meantime, I get to make the kitty laser matrix which is well, too much fun.

Edit: Chip pin reads between 0 and 1024 about ~10,000 times per second and moves higher when the laser is blocked. I have it calibrated so that pretty much nothing but the laser (within reason) will turn it off. I just set my sensitivity by deciding in code which value between 0 and 1024 is the alarm condition which will be set by another analog pin on a potentiometer.

[garcho]

wouldn't a gate just keep the cat out?

You mean, like, on a FET? Ah, there's my coat...

[Joe Kramer]

Joe! You need more posts here, you have too much to offer! Side note: The package with the PCBs to etch etc. shows "out for delivery" so I should have them today. Can't wait!

Thanks brother, I'll return from vacation with renewed energy and do what I can!  

   

[Luke51411]

What next installing lasers ON cats? Sheesh... Don't give them that power! Really though, looks pretty cool!

[Luke51411]

What stops the cat from pawing at the laser continually setting the alarm of at the most inconvenient times? That's what my cat would do...

[karbomusic]

What stops the cat from pawing at the laser continually setting the alarm of at the most inconvenient times? That's what my cat would do...

LOL, my previous cat would have taken a nap right in the middle of the beams.