為解決當(dāng)前計算機(jī)串行通訊接口只有USB，難以滿足舊型號設(shè)備或某些單片機(jī)要求RS232通訊的問題，設(shè)計出兩款RS232/USB電路。采用CH341A與MAX223集成電路芯片構(gòu)建標(biāo)準(zhǔn)9線RS232/USB通用接口轉(zhuǎn)換器，無需編程。采用CH341A與PIC16F877A構(gòu)建單片機(jī)與計算機(jī)之間的USB通訊電路，軟件遵循RS232通訊協(xié)議，硬件進(jìn)行電平轉(zhuǎn)換。實際使用表明，這兩款產(chǎn)品與計算機(jī)端Windows 操作系統(tǒng)下的串口應(yīng)用程序完全兼容，且通訊過程中無握手失敗現(xiàn)象。
Abstract: To solve the problem that current computer serial communication only with USB interface can not satisfy with the old type equipments or MCU to communicate with RS232， two kinds of RS232/USB circuit were designed.CH341A and MAX223 integrated circuit chips were used to create a standard 9-line RS232/USB universal interface convertor without programme. CH341A and PIC16F877A chips were adopted to build the USB communication circuit between computers and MCU. The software follows RS232 communication protocol， and the hardware converts electrical levels. Actual practices indicate that the two manufactures are compatible with serial application program of Windows operation system completely，and get avoid of handshake lost.
以AVR單片機(jī)ATmega8和USB接口器件PDIUSBD12為核心，基于標(biāo)準(zhǔn)的USB1.1協(xié)議，設(shè)計一種通用USB接口模塊，以滿足嵌入式系統(tǒng)中對USB接口的需求。對模塊的硬件電路或單片機(jī)固件程序的硬件接口層稍加修改即可用于其他各種微處理器。該模塊可為各種嵌入式系統(tǒng)增加USB接口,實現(xiàn)與USB主機(jī)系統(tǒng)通信。
Abstract:
Based on AVR microcontroller ATmega8 and USB interface chip PDIUSBD12, a general USB interface module is designed according to USB1.1 protocol for various requirements of embedded systems. Only with few modifications in circuit or hardware abstract layer of firmware, the module can be used on many types of microprocessors. All kinds of embedded systems can realize high speed and stable communication with USB host systems, owing to the facility of this module.
