PROXIMITY SENSOR - TBD

[daveross100]

WOULD LIKE TO USE a TBD ? device AS A PROXIMITY SENSOR TO DETECT MIRROR DOOR POSITIONS, "OPEN" OR "CLOSED" .
,AT CLOSE POSITION THE MIRROR IS ABOUT 15 TO 25 [CM] =[ 6 " TO 10"] FAR FROM THE TBD [RECEIVER AND TRANSMITTER.... [opto magnetic other not mechanical bar can be used] ?],
MIRROR DOOR MOVES TO OPEN POSITION ABOUT 45 DEGREES .

Question : What device (PROXIMITY SENSOR) TBD can DETECT DOOR distance +/- 0.5 [cm]or better from device [POSITIONS-open or close] ?
Note: device size shall be within 10 mm x 5 mm x 5 mm and not use the 930 nm light frequency.

 

[VEBill]

Ultrasonic is pretty common. The Arduino programming ecosystem can provide endless options and guidance. The modules are all over eBay and are as cheap as chips. You might also need an Arduino board to interface it back to the rest of your project. It's much easier than you may expect, as YouTube videos will explain everything and the example software is ready to download.

 

[Skogsgurra]

Is here any other meaning for TBD than the common one? Or does it just say that the sensor type hasn't been decided on yet?

Having resorted to just about any contactless technique, from reed element+magnet to nozzle with air stream in environments where high radiation killed organic insulation materials and darkened optical glass, it has often been worth-while to examine the reasons for the contactless part of the specification and what the alternatives are.

Has that been done? Or did the specifier (without thinking) imagine an arrangement that she/he thought would work and put down words that described her/his conception of a viable arrangement?

Asking such questions often leads to a simple, reliable and low-cost solution.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[Strong]

Search TBD sensor and get a lot of useless hits, so what is the definition for the OP?
Walt

 

[MacGyverS2000]

He's still deciding...

Dan - Owner

http://www.Hi-TecDesigns.com

 

[daveross100]

Thanks for the reply's ,
1-The Ultrasonic is big size if my understanding is right, please see sizes needed at my question, Thanks VE1BLL
2-The issue was not solved yet=TBD it is on a military project that is using a 3D 930nm optics. thanks Skogs....
3-Seems to me to use a receiver=RCV transmitter=Tx mechanical way, but than may have an issue with adjustments of TX & RCV [ yes STRONG !!!]
Was thinking will not have to invent the wheel ....... thanks for the answers

 

[IRstuff]

I'm not seeing the love for a Hall sensor, which would have been my first guess.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[VEBill]

Perhaps the door (cover?) or its hinge mechanism could include pegs that would trip optical sensors, blocking an optical path. The sensors are the sort with the U-shape gap between the IR LED on one side and the Phototransistor on the other side. You'd normally have one for the fully closed position, and another for the fully open position (could use just one with two pegs, but at risk of getting out of sync).

It'd be best to have a microcontroller monitor the whole thing including motor current and timings. Then report CBIT results for any excursions from normal.

Some systems might even include an absolute encoder to track the cover motion from end-to-end, and self-calibrate (learn) based on hard stops. Current spikes and lack of motion indicates the end stops. Next time approach the end stops more carefully.

In the old days, they'd used plain old mechanical microswitches with the usual reversing diodes. But these days they'd want something with "unlimited life" based on naive assumptions.

If it's a cover, such that the primary system is not used when the door is closed (or on the move), then perhaps you even could reuse the same wavelength by locking out one or the other. Maybe, maybe not - depending on the details.

 

[daveross100]

May use the VL53L0X of

http://www.st.com

this is a "Ranging sensor" up to 2 meter , that the reported range is independent of the target reflectance

 

[daveross100]

Trying to use the vishy and ST devices Was fail , very complex did not run on windows 10 , and need programming of the I2C
seems the device we will use is the simple SHARP distance sensor GP2Y0A41SK0F , 4 cm to 30 cm distance sensor that need only simple A/D to read the Analog output .