I would like to pay someone $300 (not including parts) to build me an Arduino device that hooks to three MaxBotix sonic range finders and sends back X Y Z measurements in inches.
PM me if interested. I'm in Canada.
School project?
Which sensor exactly? there are many maxbotox sensors? e.g http://www.maxbotix.com/uploads/LV-MaxSonar-EZ1-Datasheet.pdf
Seems you just need a serial port as the device provides the distance in inches on the TX line. Quite a nice sensor.
robtillaart,
I'm not sure of the exact senor and I don't care but the following looks very good XL-MaxSonar-EZ4. From my reading a narrow beam is better for my app. What I want is to locate the three sensors in XYZ space, each sensor would be 40 inches away from 0,0,0 point. I would then place a box at 0,0,0 and then the sensors could give me the length, width, height with a little math. Ideally I would want to read all 3 measurements with a single string thus the Adruino.
LxWxH or 12x20x20
I'm not an Arduino or hardware person.
One problem with what you are proposing is how to discriminate between the object, and the surface it is sitting on/against. Is there a particular reason this isn't being done with optical sensors?
That being said, the build would be quite easy, if the sensors can provide clean data. I'd suggest instantiating NewSoftSerial for each sensor, and using the standard UART for your PC communication.
All you need to do is define the output data format you would want, and just build that string of output from the three sensors.
The Arduino and electronics side for this isn't difficult at all.. I'm questioning whether the proposed system would actually work consistently..
I was not aware there were any optical sensors for the platform but I'm open to what would work the best. I have my concerns about interference/noise from the three sonar devices. The idea of the Arduino would be to cycle between the three to get readings but this is not my area .... nor do I want to pursue it 
I was looking originally at laser sensors but could not find anything but If anyone has better ideas I would love to know.
I would still pay to find out if the sonar path was doable. I mean it's an experiment and sonar devices look like the least expensive to play with.
cheers.
Your correct in your assumtion that the key decision for success is what kind of sensor you use. I've been playing with a Sharp IR analog range sensor ( a 12" model) and it looks pretty good so far. Not sure if the reflection surface of your box would work for IR, but the sensors are in the $20 each range and interface directly to a Arduino analog input pin.
http://www.acroname.com/robotics/info/articles/sharp/sharp.html
Lefty
The surface would be a cardboard so I'm not sure about it's reflective surface
The surface would be a cardboard so I'm not sure about it's reflective surface
That would work I think. The sensor doesn't use the intensity of the reflected IR light, but rather the angle that it returns at.
From the link:
"This new method of ranging is almost immune to interference from ambient light and offers amazing indifference to the color of object being detected. Detecting a black wall in full sunlight is now possible. "
so which of the sharp sensors would you use to measure anything from a 4" square box to a 36" square box?
I was reading this article earlier: Webcam Based DIY Laser Rangefinder
so which of the sharp sensors would you use to measure anything from a 4" square box to a 36" square box?
Well that is a desired measurement span of 32 inches so the following IR ranging sensor would be the best fit which has a 52 inch span (8" to 60"):
I'm not sure if I'm reading the sensor specifications correctly. Would that sensor you suggest pick up a 4"x4"x4" cube ?
I'm not sure if I'm reading the sensor specifications correctly. Would that sensor you suggest pick up a 4"x4"x4" cube ?
I think so if I understand your physical arragment correctly. You want 3 sensors (x,y,z) externally mounted to all look back at a central point (0,0,0). You then place a 4"x4"x4" box where the center of the box is at 0,0,0. So the external sensors if mounted at say 55" from 0,0,0 will measure 51" length with the box in place and 19" range if a 36" box is used instead of the 4 " box. The 8" to 60" range of the sensors would all be within measurement range of your min and max box sizes, correct?
Lefty
center of the box is at 0,0,0
Probably more like the far corner of the box. I picture three angle-irons meeting at the corner and you stuff your box into the corner for the measurement to take place.
Capturing the measurements of a box is a common requirement for the postal system. The cost is partly based on the volume, and it's a bottleneck in the process of capturing a package from the retail postal customer to be measuring with a tape and typing in the data. A POS box measuring appliance would be good stuff.
On a unrelated note, make sure the package is oriented properly so that the correct distance is measured.
Korman
I was thinking about fabricating a unit that with a corner brace to align the package.
If you still think you need to pay someone $300 for a few lines of code, I'm willing.
But, I don't think you do.