NEW PRODUCT: TSL1401-DB Linescan Imaging Sensor
Phil Pilgrim (PhiPi)
Posts: 23,514
Parallax has just introduced the TSL1401-DB Linescan Imaging Sensor:
This is a product that I've had in gestation for several years, through numerous revisions, and it's the latest in a series of linescan imagers I've been involved with since 1981. These imagers have been used for things like sorting fruit, orienting gin bottles, measuring lumber, orienting plastic heads for toy figures, tracking seams for automatic pipe welders, and measuring tires, among many others.
I hope this particular imager can find similar uses in industry. But unlike my other imagers, which sold for hundreds of dollars, this one is priced to appeal to hobbyists and amateur roboticists as well. If you have any questions or comments, feel free to ask them here, and I will do my best to answer them forthwith.
Thank you!
-Phil
Post Edited (Phil Pilgrim (PhiPi)) : 6/2/2009 10:57:29 PM GMT
This is a product that I've had in gestation for several years, through numerous revisions, and it's the latest in a series of linescan imagers I've been involved with since 1981. These imagers have been used for things like sorting fruit, orienting gin bottles, measuring lumber, orienting plastic heads for toy figures, tracking seams for automatic pipe welders, and measuring tires, among many others.
I hope this particular imager can find similar uses in industry. But unlike my other imagers, which sold for hundreds of dollars, this one is priced to appeal to hobbyists and amateur roboticists as well. If you have any questions or comments, feel free to ask them here, and I will do my best to answer them forthwith.
Thank you!
-Phil
Post Edited (Phil Pilgrim (PhiPi)) : 6/2/2009 10:57:29 PM GMT
Comments
1) Will there be lenses available to select between different colors? I haven't had time yet to go through the whole datasheet, but I assume it measures intensity of all colors.
2) How would you consider using this for a robotics application? Could it be used to measure the rate of motion if it's pointed at the ground (similar to an optical mouse I guess).
3) Will there be a protective cover made available? I'm in a constant state of fear around lenses: will I scratch it?
4) Some links to examples where this (or a similar sensor) has been used would be great.
5) Would it be possible to use this with a laser as a range finder? I'm thinking of those examples where roboticists use a webcam and a laser. Also similar in principle is the sharp IR sensors.
Looks great!
1. You can get inexpensive plastic color filters from Edmund. These can be cut to size to fit the square cavity in the lens holder behind the lens. You could also arrange a set of RGB filters on a filter wheel in front of the lens, turned by a servo. This is the way the Mars Rovers obtain color images with their cameras.
2. The two robotics apps I had in mind that would work with a Boe-Bot are line following (using a separate light source) and flame detection and location. I've done both and hope to have app notes available for these soon.
3. The lens element is fairly small and recessed enough in its barrel that the chance of scratching it is pretty slim. However, if you're still worried, you could take a 1/4" paper punch and punch a hole in the center of the included lens cover. Then cut out a thin piece of transparent plastic to put behind it before placing the cover over the lens. This technique would also work with color filters.
4. I'll see what I can find. My own customers, who used my industrial sensors, would rather I not reveal who they are or what they were doing.
5. Yes. You would need a laser line generator that you could mount some distance off-axis from the imager, such that the laser line and sensor line are perpendicular. You would probably want to modulate the laser on and off, too, so you could separate it from any bright background objects. A color filter will also help.
-Phil
How fast can it make a photographic image - one line only scan?
What is the practicality of acquiring one full image by scanning line by line (moving the sensor by servo), i.e. how long to scan a full 128 pixel by 128 pixel x-y image and save the result?
humanoido
It's entirely practical. Here is a setup I used as a quick and dirty demo. I had to use two Stamps, since my monitor software for the MoBoStamp-pe wasn't configured to rotate a servo. (It could be, though.)
Here is a snapshot of the monitor screen after one scan:
A full scan across the screen (512 x 128 pixels) takes about two minutes. The limiting factor is the 38,400-baud data rate for transmitting the pixels to the PC for display.
-Phil
Post Edited (Phil Pilgrim (PhiPi)) : 6/3/2009 5:51:33 PM GMT
When can we expect a Propeller Object in the OBEX for this one?
Any idea how many photons you need to register a signal on a pixel with this?
Great job!
A Propeller object is in the works.
-Phil
Also brilliant timing, I was just surveying what was available along these lines, for an upcoming industrial application.
can't help wondering what else you have 'in gestation'... hope the other products don't take as long to hit the market.
tubular
Since you're interested in industrial apps, I can disclose that there's an RS232 daughterboard in the works that interfaces directly to a Koyo (www.automationdirect.com) PLC via an RJ12 cable. It would plug into socket A of the MoBo, with the linescan sensor (or another sensor) in socket B. That way the PLC can power the whole system through the comms cable. The docs and DirectNET protocol PBASIC software are done. I just need to get some made. If this is something that might be of interest, please let me know.
I also want to do both a 4-20mA output module and an isolated discrete I/O module, but haven't settled on designs for them yet.
-Phil
Koyo, interesting. I've only ever come across one in this country, however I believe there may be a lot of them monitoring small gas plants (nitrogen storage etc). RJ12 is great for quick lashups though.
I don't have an immediate use for the modules you mention, but am sure to one day. I'll let you know when it happens! Good to see some more industrial options appearing for the prop.
I'm about to laser cut & mark some brushed stainless fascias for an assortment of sensors. I'd like to do one for this line scanner too, so can I trouble you for the diameter of the lens barrel? The datasheet mentions an M12 fine lens thread but not the OD which will be slightly larger.
It also looks like it would fit very tidily in a 1 1/2" square stainless tube (1.6mm wall thickness)
tubular
I've closed up shop for the evening, but I'll post a photo of the extrusion tomorrow. I'll also mike the lens holder barrel and post the diameter for you.
-Phil
humanoido
The diameter of the lensholder barrel is 0.586" at its thickest point. Here is a photo of the TSL1401-DB/MoBoStamp-pe installed in one of the extrusions I mentioned (sans endcaps and top plate):
-Phil
Here's a copy of the file that's automatically loaded into the MoBoStamp-pe by the PC host program that produced the scan shown above:
' {$STAMP BS2pe} ' {$PBASIC 2.5} io PIN 6 ext PIN 3 busy VAR Bit mode VAR Byte exp VAR Byte led VAR Byte gate VAR mode.BIT7 trig VAR mode.BIT6 strobe VAR mode.BIT5 autoexp VAR mode.BIT4 sync VAR mode.BIT3 lock VAR mode.BIT2 pixno VAR Byte pixval VAR Byte char VAR Byte(16) i VAR Byte maxbrt VAR Char NUL CON $00 SOH CON $01 EOT CON $04 BAUD9600 CON 84 BAUD CON 6 mode = 0 exp = 64 led = 0 PAUSE 10 LOW 14 SEROUT 16, BAUD9600, [noparse][[/noparse]NUL, NUL, NUL, "R", NUL, EOT] SERIN 16, BAUD9600, 200, GoAhead, [noparse][[/noparse]WAIT(SOH, "M"), HEX2 mode, HEX2 exp, HEX2 led] GoAhead: pause 10 SEROUT 16, BAUD9600, [noparse][[/noparse]NUL, ">", NUL, EOT] OWOUT io, 1, [noparse][[/noparse]$EC, 128, 8, $00, $EB, strobe << 7 | led, $EE, exp] ', $A4] GOSUB Ready DO DO WHILE (gate and ext) : LOOP IF (sync) THEN IF (trig) THEN DO : LOOP UNTIL ext DO : LOOP WHILE ext ENDIF LOW 0 : INPUT 0 PULSIN 0, 0, char IF (char = 0 OR char > 96) THEN lock = 0 ELSE lock = 1 OWOUT io, 1, [noparse][[/noparse]$A0] ELSE OWOUT io, 1, [noparse][[/noparse]trig << 3 + $A0] ENDIF SEROUT 16, BAUD, [noparse][[/noparse]NUL, "M", HEX2 mode, HEX2 exp, HEX2 led, NUL, EOT] GOSUB Ready SEROUT 16, BAUD, [noparse][[/noparse]NUL, "P"] FOR pixno = 0 TO 7 OWIN io, 8, [noparse][[/noparse]STR char\16] SEROUT 16, BAUD, [noparse][[/noparse]STR char\16] NEXT SEROUT 16, BAUD, [noparse][[/noparse]NUL, EOT] IF (autoexp) THEN OWOUT io, 1, [noparse][[/noparse]$DA, 34] OWIN io, 8, [noparse][[/noparse]maxbrt] exp = $E000 / (maxbrt / $FF + 1 * maxbrt) */ exp max 255 min 1 OWOUT io, 1, [noparse][[/noparse]$EE, exp] ENDIF LOOP Ready: DO OWIN io, 4, [noparse][[/noparse]busy] LOOP WHILE busy RETURNIt's restarted every time the host needs to change a parameter. Then it just obtains scans and sends them to the host. SERIN and SEROUT communicate with the PC; OWIN and OWOUT, with the TSL1401 driver in the AVR coprocessor.
-Phil
Regarding the extrusion, we have 300 lineal feet in stock that we'd love to start cutting up with our new automatic drop saw. I've had to move it out of the way every year on June 30 for inventory count and I'm excited about the possibility of putting it in our inventory once and for all.
I'm curious about our customer's level of interest in the extrusion. I imagine it would be around $5 a section or so. We don't have endcaps, as Phil noted.
Anybody interested in the extrusion for this kind of application?
Ken Gracey
Jeff T.
Correct. The holes are sized to be tapped #8-32. So here's a question: If endcaps were available in a black G10 (epoxy-glass laminate) material with cutouts for the motherboard only (power, USB, LEDs, reset button) in a set with a blank top plate, would that be an attractive option, assuming people could finish them themselves? OTOH, suppose the top part of the endcaps were open, with just enough meat (i.e. a frame) to hold the boards and top plate in place?
-Phil
Something easier to work with than G10 might be nice. It's not the worst thing, but there are other plastics are easier for "one off" work.
In terms of the extrusion, possibly a "double" lenght could also be offered? I'm thinking for use with projects that don't involve the motherboard, or a line of sensors along a conveyer, as well as room for a conduit connector as mentioned above.
Keep in mind that the above opinions, along with a buck or two (depending on where you are) will get you a soda from a vending machine.
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John R.
Click here to see my Nomad Build Log
I'm guessing this extrusion could also work with the Color sensor, correct?
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John R.
Click here to see my Nomad Build Log
Yes, it works with the color sensor, and all the other daughterboards. A little history here: I got stuck with a bunch of customized extrusions when a customer went out of business before buying the LED backlights they were designed for. So, when I designed the MoBo and daughterboard line, I sized them to fit these extrusions — just in case. But the extrusions were not perfect for the job. For one, it was hard to use the bottom slot without causing a short to the MoBo. Second, it really needed one more slot. So I designed a new extrusion from scratch, with a recess below the bottom slot, and an extra slot. Here's a photo that compares the old with the new:
So Parallax had a bunch of these extrusions made to my design, and they've sat in their warehouse ever since, waiting for me to do the endcaps. The extrusions, BTW, are brushed and anodized and really look nice.
For industrial apps that require environmental protection, a better option might be an IP67-rated polycarbonate box with a plastic cover, like the one shown for the anemometer project I posted a couple weeks back. I used a backplate cut and drilled to fit the box and a motherboard. (The board shown is not a MoBoStamp-pe, but a Propeller half motherboard, which also fits the extrusion, BTW.)
-Phil
That extrusion is *exactly* what I was about to get custom manufactured for an industrial project (after exhausting readily available extrusion options here). My target slot width was 35mm to allow DB9 connectors, and it looks like it will do that beautifully.
I see real possibilities for extrusions like this as an industrial quality, mechatronic, "rapid solution" system. So much so I drafted a spec for discussion and am currently working on a flexible dev system for a company known to you both. You're already half way to a really neat solution. But rather than hijack this thread any further let me tidy it up over the next day or two and PM it through with a couple of photos of where its at.
Back to Ken's question, I think there would be interest in it as-is, and you should get it into the store asap, pref sold by a unit length (one unit could be the length of the Mobo)
I can't believe what you guys have tucked away there... sheesh
tubular
I can cut whatever length you want of this material - just let me know what you want and I'll get it together for you. 3" or 3' or anything else; your choice.
Ken Gracey
Parallax, Inc.
extrusion material. Question I don't see in the replies: What size board fits the slots?
Did I understand half sized protoboard?
I don't mind cutting a board down to fit. I'd love to see the end-caps.
OBC
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New to the Propeller?
Visit the: The Propeller Pages @ Warranty Void.
tubular
The slots are sized for a board 1.35" (34.3mm) wide (i.e. MoBos and daughterboards) and spaced on 1/8" centers.
Tubular,
That would be up to Parallax.
-Phil
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I like this POST and will keep reading this one and keep up the good work
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Sam
humanoido
' {$STAMP BS2} ' {$PBASIC 2.5} FOR W0 = 1100 TO 300 FOR W1 = 1 TO 7 PULSOUT 15, W0 PAUSE 20 NEXT NEXTIt's not synchronized to the camera program. It's strictly a matter of timing, and I adjusted the inner loop timing to produce the image with the best aspect ratio. 'Quick and dirty for an instant demo.
It would not have been difficult for it to trigger the host slave program, though, since that feature is built in. It uses one of the data lines that's common to socket A and socket B on the MoBo for the trigger.
There are no comments in the slave program for the host, since it was never meant for human eyes. It exists only in the Perl source code for the PC monitor program and is uploaded automatically when the monitor program starts. I posted it here only because you asked.
The docs for the TSL1401-DB explain all the ins and outs of interfacing with the AVR driver program and include many example code snippets. It's easily the best place to start.
-Phil
Just wondering out loud here.
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Watching the world pass me by, one photon at a time.
In a typical industrial environment, it's the product that's moving on a conveyor, sometimes with an encoder signal present, so the camera doesn't have to move.
-Phil
*This is a natural consequence of extruding a U-shaped form. The only way to avoid it would have been to include a supporting web across the top and then machine it out. But that would have added enormously to the overall cost.
A minor request for the next revision - could we have some kind of indication on the PCB as to the scan line orientation? One less thing to think about.
I worked it out from the experiment photo of the money
thanks
tubular