Keep-whole modulesKeep the moduleHand tools, works as-is
USB barcode scanner
Also called HID scanner, hand scanner.
Most handheld barcode scanners from an office cleanout show up to a computer as a keyboard. You plug them in and they type the code followed by enter. That is a finished instrument, not a pile of parts.
If you are new to this category
Some scrap is already a finished object: a webcam a computer recognizes, a barcode scanner that types numbers, an amplifier board between a jack and a speaker. Opening these to pull a chip almost always throws away the useful thing. If it still works when you plug it in, stop there.
Test the whole module before you unscrew it. A working webcam is worth more than the parts inside a dead one.
Plug the module in before you take it apart. A webcam the computer already sees, a scanner that types into a text box, or a speaker board that plays music is the finished part. The chips on the board are not an upgrade.
Extracted laser diodes. Inside a player the diode is a Class 1 product because of the optics and the power limit. Pulled out and overdriven, DVD and Blu-ray diodes are an eye hazard, including the infrared one you cannot see.
| What to look for | Usual figure |
|---|---|
| Interface | USB HID, or a PS/2 wedge on older ones, or RS-232 on the industrial ones. The connector tells you. |
| Config | A sheet of barcodes in the manual sets the suffix and the symbologies. If you do not have it, search the model. |
Volts are electrical pressure, amps are how much current is flowing, and ohms are how hard the part resists that flow. A higher voltage than the part was built for is how salvage parts die on the bench. If a cell in the table says “read the stamp”, that stamp is the whole specification.
What people actually use it for
- Inventory
- A quick input device for anything that can accept keystrokes
Leave this one when
The scan engine is dead and you wanted the laser. See laser diodes, and then don't.
Buying a new one is the better idea when
Only if this one will not enumerate. The module is the product.
How to tell if this one still works
Plug it in, scan something, look at a text editor.
Tools you will want: A computer.
Where people actually find it
1 notes, most useful first. “Leave it” means the part is in that machine and you should not take it: it is dangerous, worn out, or only useful if you already know that exact repair.
| From | Call | How many | How often | Where it sits |
|---|---|---|---|---|
| Barcode scanner | Prize | 1 | usually | The whole unit. |
- In this particular machine
- USB HID keyboard wedge, sometimes RS-232.
- Where to look
- The whole unit.
- How to get it out
- Test it. Find the manual for the suffix codes.
- The condition to expect
- Usually good.