Zonal Range Finder using TSL1401

VRizzo

I need the ability to detect a moving object within 3 zones. Zone 1 is 5 to 15 feet from the sensor, Zone 2 is 15 to 30 feet away, and Zone 3 is 30 to 45 feet away. All I need to know is what zone the moving object is in.

I plan on scanning the area with the sensor mounted on either a stepper motor or servo, but first things first. I need to get the sensor working!

I have looked at a Maxbotic acoustic sensor but the range when detecting soft objects like humans or animals is only 10 feet.

I currently have a TSL1401 mounted along side a Beamshot Ultra laser. I figured I would use the triangulation method. To prove feasibility, I am using the TSL1401-Monitor to verify a shift in pixels depending on distance.

I am seeing a shift, but only a few pixels from Zone to Zone. I would expect significantly more than that.

Does anyone have any ideas? Does this sound possible using the TSL1401?

Phil Pilgrim (PhiPi)

You can increase the apparent pixel shift by moving your laser much further off-axis. Another thing that could help is using a longer focal-length lens to narrow your field of view.

-Phil

VRizzo

Thanks Phil for your reply.

The laser is currently 3.5" from the sensor. Should I look at doubling or tripling the distance?

Do lens options exist for the TSL1401 or do I have to order a different lens from someone like Edmunds and plunk it in?

Phil Pilgrim (PhiPi)

3.5" is way too close for a 45-foot range. Can you move the laser out a couple feet or more?

Regarding lenses, anything with a 12mm x 0.5mm thread should work. The supplied lens has an 8mm focal length. So if you can get one at least double that, it should help. Any lens designed for a 1/3" or larger sensor should work fine. In addition to Edmund, try these suppliers:

Universe Kogaku
Marshall Electronics
Sunex

-Phil