Best barcode scanner

[danrogers]

barcode scanner circuit

Hi all could someone link me to a good barcode reader circuit? I am going to have a go at making one. i guess IR scanners are easier to make than laser?

The more simple to implement the better

Thanks

 

[Reloadron]

Not sure what you mean? I have and use Adesso Barcode Scanners and like them. But you say "Best Barcode Scanner" then go on to say reader circuit? What exactly are you trying to do?

Ron

 

[danrogers]

Hi Ron, I was a bit tired and not thinking straight earlier!

I have just edited the post

I'm going to have a go at making one, possibly with a screen to display the number it reads off

 

[Reloadron]

If you have not found it yet, this article is a good read. Several years ago I did a project but the hand held scanner was provided (I got to keep it) and it was an Adesso Nu Scan 3000 (USB Interface).

Scanners themselves come in a few flavors as to how they do what they do. All I did was populate some text boxes on a form then the user clicked a button and it brought up data on the item scanned.

Ron

 

[cr0sh]

Technically, the electronics and optics are fairly easy to implement; basically the same kind of setup as the reader in a rotary encoder (an LED focused on the surface to be scanned, reflecting to a phototransistor). Unless you are looking to get into a "contactless" (that is, held a certain distance from the barcode) reader - then the optics can become more complex to implement. I would start with a contact scanner (ie, one that requires the barcode to be within say a few mm of the LED/sensor pair).

Now this setup, when you run it past (or run past it) the barcode, will generate a series of high/low pulses, the width of each determine the value of that point in the code. IIRC, there's also checksum and other values to help you know what direction the barcode was scanned (so you can reverse it if necessary). You basically have to record these pulses, analyse them, then decode them (reversing them if needed), and verifying them using the checksum (if implemented for the barcode type - there are several different standards available) - then outputting the data to your display.

All of this would be best accomplished using a microcontroller; for the code/algorithms needed, google is your uncle (look up "barcode decoding algorithm" and the like - tons of stuff out there to work from).

 

[danrogers]

thanks for the help guys, and the link Reloadron - will have a good read later and continue with some research. I will be back