I recently bought a “Mini 1D/2D Barcode Scanner Module Bar Code Reader Scan Module Fast Decoding USB” for an upcoming project.
However as is often the case with Chinese eBay items, there was no documentation and a Google search only found other sellers of the same thing.
The only markings on the board are “YK M4A”. Although I also found reference to “YK-E2000”; there was still no sign of a data sheet or pinout diagram.
After much wrangling, the seller managed to provide me with the pinout diagram to actually connect the thing up (The note for pins 13 & 14 said “Note: These pins are grounding pins to stabilize both sides of power strip” which I think actually means that they are the mechanical support for the connector).
The connector is a 0.5mm pitch FPC with a 60mm flat flex cable provided. I am now waiting for a connector and breakout board so I can test it (and find out if both the RS232 TTL and USB are enabled together or if the firmware only provides one or the other).