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Processing Count.

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Current Situation: workers take a wide veriaty of objects and classify them into several price categories. The items are placed in bins cooresponing to the value (.50,1,2,3,4,5,6,7,other). Another person goes to each bin, makes tick marks on a tally sheet to count items by price, then sorts them into baskets to be taken to other processes.

Problem: Tick counts are extreemly unreliable and other methods of counting are two intrusive to the process (at this point)

Solution Attempt: Place a button in each bin that can be hit each time an item is placed in that bin. These button hits should be sent to a serial port or other port on a nearby computer. Once I can get a signal into the serial port of the computer, I can take it from there.

Attempt 1: Looking into PLC's and building ladder logic to count the button clicks and send to serial port. This seems to be kind of overkill. I would bet there is a simpler solution

Attempt 2: I have taken the logic board from a computer keyboard , mapped the imputs on the bard, carted switches to replace keys, found a way to distribute the buttons. It works, but is kind of kludgy and is a real wiring birds nest. There has got bo be an easier way (or at lest cleaner) using IC's

Anybody want to help brain storm this with me? There is no money to be made (all this is for a none profit thrift agency), but it may be an interesting challenge.

Charlie R Chisholm
The simplest solution to this which I can think of is to use Modern Digital Weighing Scales which also has product counting facility. To count the number of pieces, all you have to do is put the machine in counting mode, put one piece of product, let the machine make a record of it and then put your entire bin on the platform. The machine will immediately show the number of pieces. Also facility is available to auto-zero or offset the weight of the bin. So this is not a problem out here.

I am looking forward to see if anyone has any better ideas.
well charlie if u are to send the signal to the computer sooner or later,
then y have any processing at the 'bin' at all. just fix a fm transmitter
on the bin and an fn receiver at the compu such that any press on the bin causes a 'press' at the compu and do what u want to do with it right there on the compu. (i.e. count them or whatever).

though u would like to modulate/demodulate the 'pressses' to eliminate false triggering but thats a trivial job.
also doing all this wirelessly isnt important as u havnt mentioned that.

this can b built in some 5 to 8 dollars.
i m not sure how much a new weighing machine wu cost.
I would also like to add one more thing. These new weighing scales have a RS232 port so you won't have any trouble connecting it to the PC.
You can buy a 5kg weighing machine at around $100.
Now the rest of the story: Sorry, I didn't do a great job of explaining the problem.

The objects we are "processing" are donated goods. We have no idea what they are ahead of time. These objects are broken onto six major categories and then by value. The value given to the object ranges from 50 cents on up. At this point, we are only interested in three categories (textiles, books, and Shoes) and the price ranges in each of .50,.75,1,2,3,4,5,6,7, and >7. There is a bin for each value point, but the object may be any one of the tree categories.

Now, the keyboard device that I created put three buttons in each bin. One button is to be mapped to one alpha numeric key stroke on the computer and the other two would be mapped to the alt or ctrl keys, thus changing the ascii code returned by the first key. The problem with this arrangement is that it is a wiring nightmare. I don't have any problem getting the buttons out to there locations using a conventional 25 conductor serial cable. The problem is at the machine with the device that replaces the keyboard. First, there is now no keyboard for other functions like bulk entry, and second, it looks like an old style switch board from the early 20th century.

I was hoping that there might be a way to send back a numeric value to the serial port indicating the bin and category selected What I would truly like to have is something that could send back something in the form BBCC where BB would be bin 00 throu 99 and CC would be category 00 through 99.

Do we feel challenged yet? Please remember that you are talking to a software developer who is interested in electronics and even started an EE degree, but never got past the point of understanding simple electricity and a extreemly vague understanding of resisters, capasitors, and diodes and such.

Thanks in advance. You'all are great for even considering this mess.

charlie i didnt quite get ur requirment properly.

what i get is this. correct me if i m wrong.

1) there will be a queue/row of bins.
2)all bins would be similar
3)pple will come with the goods.
4)one would come, stand in front of the bin, choose a number using the keypad on the bin to specify the cost of the item in his/her hand, and then drop the thing in the bin ?
5)te bin would then send this number(cost) augumented with its (bin's) own number to a computer so that u can keep account of the collection ?

seems to b a trivial thing except that u would need a arbitration algorithm
to keep the bins from talking to the computer simultaneously.
in any case it would b fun to write the software for this thing.
Very close.

1) People will place goods in bin according to their value.
2) Another person will go down the row of bins and click a button once on each bin for each item in that bin. Since the goods in the bin might fall into one of three categories (books, shoes, or textiles) , then I would need ether three buttons for each bin, or a momentary switch indicating that (now I'm books, or now I'm Shoes, or if no category button is pressed, I am Textiles)
3) The items will be removed from the bin and go to the next process.

#2 is where I am. I just need a way to get these button pushes into the serial port of the computer. I can create the software to read the serial port and get the data where it should go. As you said, the problems are before it gets to the computer. Simaltanious button pushes would have to be considered, but I could live without solving that right away. Mainly, I guess the question is... How can I turn a button push into a signal that would identify which category is selected and which bin it was in to the serial port of the computer.

I read this three times and it even confuses me, so please ask any question that will clerify.

so initially the bins will be labelled something like "$ 0.5", "$1", "$2", etc.
so that pple will put items worth $ X on the bin labelled "$ X" ?
i.e. all items (be it books,textiles, or shoes) priced equaly go in the SAME bin.
they dont do any 'button pushes' ?

then an employee visits each bin, looks whats the topmost item, presses button 1 if its a book, 2 if a cloth or 3 if a shoe. right ?

so the net goal is to have just three buttons on the bin ?
pretty much, you got it.

Just so you know, the overall goal is that we have never been able to quantify this process, so if we make any changes to what people do, we have no way of knowing if it helped or not. If we can get a handle on how much of what stuff is processed in a given time, we know if we are making things better or worse.
any idea how many bins in all there would be.
i.e. in case there r multiple bins per "$ X" category.

asking this to b able to decide what chips to use.
There are, at most, two sets of bins with the same value, so a total of about 20 bins. There is also another processes that works very similar to this except that there are no bins...only piles of clothing. These items will also be broken down into value categories, but I would think on another computer in another location. I would imagine that any solution to this problem could be made to work with the clothing also.

BTW, I said earlier that the three categories are Textiles, Shoes and books. It really dosn't make a diferance, but three categories are WARES, shoes and books.
sorry for making this post late but one more question.

will the employee be visiting the bins in a preset order or just in any random order.

cos if its done in order, then there wont b any need to transmitt the bin number. and in that case i might b able to come up with a schematic quite soon though i m going quite busy nowadays.
also the circuit will b for parallel port.

on the other hand if the employee visits the bin in random order then this topic needs a bit more brain storming.
Since we can't predict what will come in, there is really no order that they would follow. It could be that there are items in the first couple bins, then nothing for a few and so on...

The parellel port would work great.

I appricate that you are busy and am very appriciative that you can even consider this. If it were not for the good help of people like yourself, the non-profit industries like mine would not survive. Thank you very much.
Parellel Port

How many inputs does the parellel port have? It seems to me that if there were 8, I could use 2 to indicate the category and six the bin. That would give me 0 through 63 for bin numbers. If I could set a dip at each bin to indicate the "address" of the bin, then I would have to figure out how to read the perellel port and I would have it.

Am I over simplifiing it? Seems like ther might not be 8 inputs to work with.

Sorry if I am not looking at this correctly.

Can I add a comment.
This design may be affected by a 'collision' per say should two buttons be pressed at the same time. This may cause the 3->2 encoder to register an incorrect value... :?:
A priority encoder can solve this problem and generally most encoder ICs have these in-built so it won't cause any trouble.
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