Hi
few year back when i playing to make my own pick place i got idea to use
Barcode scanner as vision system ,and never got opportunity to try this
since i just buy a lot of barcode reader and 1 have broke handle it time to play
so it use nice linear CCD whit 3648 pixel all that fit on a box whit optic in place
put 5 volt supply and internal pcb start scan the sensor ,just need to tap into desired signal
http://www.oceanoptics.com/technical/de ... 1304ap.pdf
we need "shift gate" , clock ,"analog out" signal for make thing easy analog was route to a voltage comparator and feed into a interrupt pin of a ardunino or similar same for shift gate and clock .. ( i let you do code part since i now own 2 MyData pick place so DIY project was dead)
"shift gate" pin was trigger for start a counter and take clock as clock source
then you use comparator out to latch counter value for raise and falling edge of signal
raising edge was part start and falling was part end , counter value between the 2 edge will tell you part dimension and value from start the distance from pixel 0
so on machine setup you need to find nozzle position (clock cont) then whit bit of math
you able to got if measured part position from nozzle position ...
since i knot that i not clear sometime since english was not my first language
let see image ... http://youtu.be/fFdDQuVusrw
white trace = analog out , green trace = "shift gate" and yellow = clock
when i put the 30awg wire you see wire position and pulse width = wire width
and if it see a 30awg wire it will see any part whit no issue
feild of view was bit under a inch so in theory you may resolve 1/3648 of a inch
ok so i let you complete that project .. some minor note i found useful ..
1-) for work need a white back ground since no back ground = like it see black and part are black
2-) background need to be a 45 deg angle , if not CCD will see part shadow on the background
3-)barcode i use was IT3800 CCD barcode scanner it come in ton of clone model to ..
p.s. if some one was ambitious it may also use a bottom vision and use X or Y for simulate more CCD line by swipe part over the sensor just like MyData line scan camera but that need opti swap ...
DIY Camera for Pick & Place the easy way ..
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- alphatronique
- Posts: 231
- Joined: Fri Jun 25, 2010 8:30 am
DIY Camera for Pick & Place the easy way ..
- Attachments
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- optical block detail
- ccd2.jpg (53.45 KiB) Viewed 2137 times
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- CCD module and setup ...
- ccd.jpg (60.77 KiB) Viewed 2141 times
- alphatronique
- Posts: 231
- Joined: Fri Jun 25, 2010 8:30 am
Re: DIY Camera for Pick & Place the easy way ..
Hi
Have play a bit more ,initially i expected that analog signal was send through a ADC
to a DSP for decoding the barcode .
but got surprise to find that it actually make most of the job for us
it filter signal ,do automatic gain control and turn it into 3.3V TTL signal pulse
so mo need of voltage comparator and seting it all was done by itself
just need to hook into the right test point , please refer to this image for the Test point
and i include image of a real bar-code and one of the same 30awg wire
so just need to hood to a CPU and write some code
Have play a bit more ,initially i expected that analog signal was send through a ADC
to a DSP for decoding the barcode .
but got surprise to find that it actually make most of the job for us
it filter signal ,do automatic gain control and turn it into 3.3V TTL signal pulse
so mo need of voltage comparator and seting it all was done by itself
just need to hook into the right test point , please refer to this image for the Test point
and i include image of a real bar-code and one of the same 30awg wire
so just need to hood to a CPU and write some code
- Attachments
-
- 30 awg see from Test Point
- TEK00000.jpg (110.43 KiB) Viewed 2131 times
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- real barcode see from the TP
- TEK00001.jpg (86.7 KiB) Viewed 2131 times
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- Test point location
- ccd3.jpg (249.46 KiB) Viewed 2131 times
Please be positive and constructive with your questions and comments.