如何切换RTS PIN？

我用PIC32 MX795F512L实现了USB串行连接。我想用MC2200突破模块和SpkFun RS485突破模块来实现USB到串行到RS485的连接。我已经通过手动切换RS485模块的RTS引脚，检查了从MC2200到RS485的TX和RX。现在我需要从MC2200中切换RTS引脚，有没有方法可以切换RTS引脚？



      以下为原文

    I have implemented the USB serial connection using the PIC32MX795F512L. I want to implement USB to Serial to RS485 connection using MCP2200 breakout module and Sparkfun RS485 breakout module. I have checked both TX and RX from MCP2200 to RS485 by manually toggle the RTS pin of RS485 module, its working. Now I need to toggle the RTS pin automatically from MCP2200, is there any way to toggle the RTS PIN?