Shenzhen Xingtong IOT Technology Co., Ltd.
Barcode Scanner Manufacturer with development & Invention ability
Meta description: Compare USB HID, USB CDC and UART interfaces for embedded barcode scanner modules used in kiosks and OEM equipment.
The right interface depends on how the host software needs to use the barcode data.
| Interface | Best For | Main Limitation |
|---|---|---|
| USB HID | Fast testing and simple data entry | Sends data to the selected input box |
| USB CDC | Software control through a USB port | Software must handle USB reconnection |
| UART | Fixed connection to a controller board | Requires hardware wiring |
USB HID: Simple Data Entry
USB HID makes the scanner work like a keyboard. After scanning, the barcode appears in the selected input box.
It is easy to test and does not require the software to open a communication port. It is suitable when the host only needs the barcode result.
HID becomes less suitable when the software must control the scanner. If another window takes focus, the barcode may be entered in the wrong place. Long QR data may also take more time to arrive as keyboard input.
USB CDC: Scanner Control Through USB
USB CDC creates a virtual serial port. The software reads barcode data directly from this port instead of receiving it as keyboard input.
The host can also send commands to trigger scanning, change scanning modes, enable or disable barcode types, and set prefixes or suffixes.
CDC software should be able to find and reopen the port after the scanner or host restarts. A properly designed USB cable with twisted data wires can improve the physical connection, but the software must still handle USB reconnection.
UART: Fixed Connection for OEM Equipment
UART connects the scanner directly to the customer’s controller board. It does not use a USB virtual serial port, so there is no USB driver or enumeration process.
For fixed OEM equipment and custom mainboards, XTIOT engineers normally recommend UART when the host hardware supports it.
XTIOT scanner modules use 3.3V UART logic. Their default baud rate is 9600, and other baud rates can be configured.
Which Interface Should You Choose?
Use USB HID when the scanner only needs to enter barcode data.
Use USB CDC when the host has a USB port and the software needs command control.
Use UART when the scanner will be connected permanently to a custom controller board.
XTIOT models such as the XT206M1 and XT206H1 are available with USB HID, USB CDC and TTL UART interfaces. Serial integration uses the XTIOT communication protocol and does not require an SDK.
