The wireless printing module is built on the ARM-based AT91RM9200 processor, with its software platform running on the Android operating system. By integrating with the Linux kernel’s CUPS (Common UNIX Printing System), the system enables direct file printing from an Android device. While Android provides robust support for mobile and embedded applications, it currently lacks native USB printing capabilities and specific printer drivers. This paper introduces a novel wireless printing solution that leverages open-source Linux drivers and CUPS to enable USB printing on Android devices, bridging the gap between application-level interfaces and kernel-level configurations.
The overall system design involves an embedded printing module that receives files via WiFi, displays print queue information on an LCD screen, and sends the data to a USB printer through the USB interface. The system architecture includes key components such as a core processor, a WiFi module, a USB printing interface, and a graphical display. The hardware design uses the Atmel AT91RM9200 as the main controller, along with the Philips ISP1161A1 as the USB host controller, which supports full-speed and low-speed data transfer. The WiFi module utilizes the RTL8187 chip, while the display features a 320x240 color LCD with touch functionality controlled by the S1D13503 and FM7843 chips.
The software platform is based on Android, with a streamlined and cross-compiled version of the OS. The user interface is developed in Java, and JNI (Java Native Interface) is used to access the print framework. This allows communication with the background print service, following the CUPS standard. The system also includes a CUPS printer driver that supports various printer languages, such as PostScript, PCL, and ESC/P, enabling compatibility with different printers.
The backend filter handles the USB interface, allowing the system to communicate with the connected printer. The driver initialization process includes setting up the I/O buffer, configuring the USB host chip, and enumerating the connected device. Once the printer is recognized, the system checks its status and initiates the printing process using appropriate commands. After printing, the system resets the printer and waits for the next request.
Experiments were conducted using an HTC smartphone to send text files to the print module, which was connected to an HP laser printer via USB. The results demonstrated successful printing, with the system displaying a configuration interface and a print operation page. The proposed solution addresses the lack of native USB printing support on Android devices, offering a practical and efficient way for users to print files directly from their smartphones or tablets. This innovation enhances user convenience and expands the functionality of mobile devices in office and home environments.
Cixi Xinke Electronic Technology Co., Ltd. , https://www.cxxinke.com