I have a simple USB barcode reader which I intend to use to scan COD 39 barcodes. I know that just scanning the barcode while having a text field on focus will get me the text input of the barcode I'm scanning. However my requirement is a bit different.
I need to create a C# application where upon reading a barcode it will check the read barcode with a list I have to see whether it exists. The problem is I cannot keep a text box on my app in focus all the time as the app does other things as well. Instead what I want is for my program to keep looking for some sort of "event" which will be raised once the bar code scanners scans a code.
So does anyone know if there is such an event which will be raised when the barcode is scanned some code so I can instruct my program to do the rest of the work when the scanners scans a barcode?
Ideally, the scanner would've come with some kind of SDK or library that you could use.
Less ideally, you may have to resort to reading it as if it's a serial port.
Actually, you should probably read the following link instead. as I was looking up how to do that, I ran into a similar post already on StackOverflow with a similar answer.
Reading from an USB barcode scanner
Related
right now I am using a barcode reader connected to the computer via usb. The reader in question is an optic one of the brand Alberici, model LT-B001-0010.
I use this reader to scan health cards (ehic), and I would need to save the scan image and save the barcode string.
My problem comes from the fact that the reader in question is not sold with its own software for use and therefore I can not use it as I would like.
I tried to use a couple of software but they were either not functional or were not compatible with the barcode reader.
Although it should simulate a keyboard, the situation is a bit ambiguous because if I open the notepad and scan the ehic the barcode reader does not automatically write it to the text file.
Does anyone have any advice on how I should move? A software that could help me, lines of code, it’s all right as long as it’s functional.
Thank you
R.B.
I am currently implementing a web app with the goal of keeping track of the location of all the packages in a company I am working for. Our plan is to have a barcode for each package and scan that barcode at the different sectors of the company, indicating where they are. The problem is that I have no idea where to start. I've done some research on Google but haven't found much. My main questions are:
How do barcodes work in the first place?
How do you program with barcodes? Is there a specific language I should use? Do I have to buy anything?
How do you read barcodes and enter them in your program and how do you generate them in the first place?
Any hints on how I should proceed with my implementation?
I look forward to hearing back from you as I need to implement this as soon as possible.
This is a pretty broad question, but I'll do my best to answer:
How do barcodes work in the first place?
Essentially, for this type of project, you can think of the barcodes you're going to be implementing as merely serial numbers. If you really want to know how barcodes work, Wikipedia has a pretty good write up - but essentially, at this level, just think of them as a serial number, encoded in such a way that a machine can read it.
In your web app, you'd be taking a number (say, 42) that has no meaning on its own, and associating with a package and a location.
How do you program with barcodes? Is there a specific language I should use? Do I have to buy anything?
You don't really "program" with barcodes per se... Again, it's just a machine readable implementation of some kind of information. In terms of "specific language", just build your web app as you already are, and add, say, an extra integer field. The integer doesn't mean anything on it's own - it's just going to be what's printed in the barcode. In this use case, you don't even have to have a barcode per se - you could just write it on the box! The usefulness of barcodes comes in speed and accuracy of data entry - you'd be having a computer device scan the barcode and type it in instead of a human.
How do you read barcodes and enter them in your program and how do you generate them in the first place?
It doesn't sound like you're at the point where you're doing any kind of machine vision or anything, so the most common entry method would be to buy a basic USB barcode scanner, like a Symbol LS2208. Use the manual that comes with it (or you can download the manual) to configure it as a keyboard emulation device - that way, your user would just select a field in the web app, scan, and the scanner would type out whatever was stored in the barcode (in the example above, the number 42).
As far as generating, depending on your volume, you have lots of options. For low volumes, you can find a generator online and print them out onto Avery label-type sheets using an inkjet or laser printer. You could also find a barcode font and print right from, say, Word, onto a label sheet. For higher volumes, you could purchase specialized software and use a label printer, or you can even write this yourself. Personally, I have a Zebra LP2844 with a network interface, and I wrote some custom PHP to send commands in the printer's native language (EPL2) over a socket to print onto roll labels.
EDIT: You'd probably want to use either Code128 or Code39. These are two different "symbologies" (types of barcode) that are appropriate for what it sounds like you're doing. They're 1-dimensional (like UPC codes and not like QR codes), so a cheap reader can decode them, and they're pretty flexible and VERY common.
Any hints on how I should proceed with my implementation?
Just think of barcodes, the way that it sounds like you want to use them, as arbitrary serial numbers that don't mean anything on their own. For example, doing this sort of box tracking in a previous warehouse environment, we printed THOUSANDS of unique serial numbered barcode labels. Those labels didn't have ANY value until they were attached to a box and a picker started to put stuff into that box. They were just numbers. Just remember to keep them unique.
I'am developing a server for a GPS Tracker that can send pictures taken by a camera connected to it, inside a vehicle.
The problem is that I follow every step in the manual and I can't still decode the bytes sent by the tracker into a picture:
I receive the picture in packages separated by the headers and "tails", each one. When I receive the bytes I convert them into hexadecimals as the manual expecifies, then I have to remove the headers and "tails" and apparently after joinned the remain data and saved as a .jpeg, the image should appear, but it doesn't.
the company name is "Toplovo" from China. Have anyone else solve something similar?
Are the line feeds part of your actual data? Because if so I doubt that's supposed to happen.
Otherwise, make sure you're writing the file in binary mode. In some languages this matters. You didn't really specify, but make sure you're not in text mode. Also make sure you're not using any datatypes unsuited for hexidecimal values (again, we don't even know what language you're using, so, it's kind of hard to give specific suggestions.)
I'm pretty much a noob. I've been wondering how mobile barcode readers worked. I've seen several apps on the market that would let you scan a barcode, and then show you corresponding product data.
I was wondering where the product data typically comes from. Is it usually from a built-in database, or do apps tend to connect to a server to access a database?
Thanks for any and all assistance!
Barcode readers/scanners work by using some sort of standard format to communicate data to the device 'reading' the code. There are typically two types of 'barcodes' used today:
The standard Barcode - often referred to as a UPS code
And the QR code - popular for cell-phone apps.
From a developer's standpoint, both work the same way:
A device 'reads' the code, the code is interpreted to represent a set of numbers (typical of the standard Barcode), or numbers and characters (QR code).
The interpreted code is used to seek the related data in a database somewhere - A UPC code would have a database of items referenced with a number (just like the number you would read at the bottom of a UPC label), and a QR code frequently references a URL that can be opened in any web browser.
The information from a barcode comes from the referenced data that the barcode points to - so you don't have to carry around a database of information anytime you want to scan a code - you just have to be able to connect to that source of information.
Hope this helps.
I have a very specific problem: I want to write my own DMX-Software to control our DMX-fixtures. Does anyone know a interface to use? It would be great if there would be any Framework for using it, so that I only have to sent the channel and the value to the interface.
I noticed your question was for Mac, but I wrote a Windows specific C++ program, which could probably be easily modified. It's adapted from the C# example on Enttec's OpenUSB website. See:
https://github.com/chloelle/DMX_CPP
There's some really good information & code samples (including a working class that I wrote) here: Lighting USB OpenDMX FTD2XX DMXking
Ultimately, you end up setting byte values (between 0 and 255[FF] (brightest) in a byte array.
It's fairly trivial to implement simple effects such as fades or chases.
You would need to use a USB controller to convert your program's instructions to the actual hardware.
I suggest using a simple iphone application talking to a webservice which then interacts with the hardware.
Code samples above are in c# though will show you how to interact with a DMX controller