Post by thread:[OT]: oyster sizing

Would this have any similarities to weighing chickens? If so, I think this topic has been well covered in the past <VBEG>. Dan On Wed, 13 Dec 2000 22:18:04 -0700, Robert Rolf wrote: >How about KISS? >Just pass them single file through a gate/tray that weighs them. >Or do you get short oysters that weigh more than long ones? > > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Yeah, like what is somebody supposed to do with US$5, Dan? Andy Dan Michaels <spam_OUToricomTakeThisOuTUSWEST.NET> on 12/14/2000 03:17:55 PM Please respond to pic microcontroller discussion list <.....PICLISTKILLspam@spam@MITVMA.MIT.EDU> To: PICLISTKILLspamMITVMA.MIT.EDU cc: (bcc: Andrew Kunz/TDI_NOTES) Subject: Re: [OT]: oyster sizing At 02:09 PM 12/14/00 -0600, you wrote: >Would this have any similarities to weighing chickens? > >If so, I think this topic has been well covered in the >past <VBEG>. > Hey did anybody ever win that $1000[OZ] that was offered a few months ago for weighing chickens? -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

The oysters have to be sized by length to supply restaurants. They do not want them sorted by weight. (PLEASE NOTE! I don't want this to be another chicken thread.) I would just like help with links to information on scanners and equipment? The solution being considered is to use three lines of leds (8 leds in a line) and phototransistors (8 matching the leds) with the signals going into a microprocessor. When an oyster has passed the last led row the other two rows are sampled to determine the length. (small, < 60mm, medium, 60 to 70 mm and large, >70mm) The leds are driven from a 4060 cmos oscillator and counter and a drive transistor at 3600hz. Each line of phototransistors are fed into an 8 input nor gate then through a 4046 PLL to detect the presence of the pulse train. The output of each PLL is connected to the microprocessor input. The microprocessor can then acutuate a gate to redirect the different sizes. The application is complicated because of the wet, dirty condition of the oysters. Thanks Edgar. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Edgar Twining wrote: ..... >The solution being considered is to use three lines of leds (8 leds in a >line) and phototransistors (8 matching the leds) with the signals going into >a microprocessor. > ........... >The application is complicated because of the wet, dirty condition of the >oysters. Hmmm, how are you keeping the sensor circuitry clean? Probably a lot of splashing and humidity and condensation in this environs. I wonder that the gameboy camera chip that Alice mentioned a few days ago wouldn't be good for this type of app. - danM -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Some of the following companies sell all in one area sensors: Banner Engineering http://www.baneng.com Pepperl + Fuchs http://www.pepperl-fuchs.com Honeywell http://www.sensing.honeywell.com Sunx (no url known, US distributers are: Ramco Electric Co. 800-280-6933 Sunx Sensors 800-280-6933 Optek http://www.optekinc.com I know that sunx has area sensors. I think some of the others do as well, but I don't have the time to look. Essentially photoelectric line of sensors space 20mm apart in a line. I didn't look to closely, but I imagine they have a diffuse reflective mode which could (with a little coaxing) tell the difference between the conveyer and the oyster. They are pricey, but you'll tear your hair out trying to make something of your own. -Adam Edgar J Twining wrote: {Quote hidden}> > The oysters have to be sized by length to supply restaurants. They do not > want them sorted by weight. > > (PLEASE NOTE! I don't want this to be another chicken thread.) > > I would just like help with links to information on scanners and equipment? > > The solution being considered is to use three lines of leds (8 leds in a > line) and phototransistors (8 matching the leds) with the signals going into > a microprocessor. > > When an oyster has passed the last led row the other two rows are sampled to > determine the length. > (small, < 60mm, medium, 60 to 70 mm and large, >70mm) > > The leds are driven from a 4060 cmos oscillator and counter and a drive > transistor at 3600hz. > > Each line of phototransistors are fed into an 8 input nor gate then > through a 4046 PLL to detect the presence of the pulse train. The output of > each PLL is connected to the microprocessor input. > > The microprocessor can then acutuate a gate to redirect the different sizes. > > The application is complicated because of the wet, dirty condition of the > oysters. > > Thanks Edgar. > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

imho, examine egg sorting equipment. It uses shaped inclined rollers, no electronics. Similar devices exist for veggies etc. One of them might work for oysters. They are notorious for working even if submerged in dust and mud (this is a design requirement). Some of them *require* a steady water stream to run through the product to help moving it. Sorry about no PICs ;-) Peter -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam.....mitvma.mit.edu with SET PICList DIGEST in the body

>(2) LET THE OYSTER COME BY ORIENTED ANY WAY IT WANTS. > In this method we will acquire a "snapshot" of the oyster's shape. >An x-y array of sensors is used. As soon as the presence of an oyster >is detected, the state of each photo-cell is stored in a memory array. >This memory array is then "scanned" horizontally, vertically, and >double diagonally. The largest "shadow" is then assumed to be the length >of the oyster. It is best if only one oyster at a time is over the >sensor array, but the layout actually does tolerate more than one >oyster, and it also tolerates a fair amount of "noise" in the form >of debris. In software you simply ignore anything that is smaller >than a certain size. I saw something like this done to read a hook carrying an item on a conveyor belt. The hook had been drilled with holes to give it a 16bit number plus a direction bit and a couple of parity bits. two parity bits were needed as the holes were drilled as 2 columns on the hook, so one column had 9 hole positions, and the other 10 hole positions. The reader used an 1802 CMOS micro, which was programmed with several tables to allow for various angles of swing of the hook when the reader took a snapshot of the LEDs as the hook passed through the reader. System worked very well, and I was not aware of any misreads due to problems with the hook movement through the reader. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads