我想用CH340做一個簡單的工具，單片機和上位機通信，單片機除了和CH340通信，還可以傳遞出兩個低電平信號，我想用CH340得到這兩個低電平信號，但不知道上位機如何檢測到傳遞過來的信號，應該用到的是CTS#和DSR#，請指導下在上位機程序中如何檢測CTS#和DSR#變?yōu)榈碗娖剑?/p>

到參看一下windows API 函數(shù) GetCommModemStatus 的使用。

Syntax

BOOL?WINAPI?GetCommModemStatus(
??__in???HANDLE?hFile,
??__out??LPDWORD?lpModemStat);

Parameters

• hFile

• A handle to the communications device. The CreateFile function returns this handle.

• lpModemStat

• A pointer to a variable that receives the current state of the modem control-register values. This parameter can be one or more of the following values.

  ValueMeaning

  MS_CTS_ON
  0x0010

  The CTS (clear-to-send) signal is on.

  MS_DSR_ON
  0x0020

  The DSR (data-set-ready) signal is on.

  MS_RING_ON
  0x0040

  The ring indicator signal is on.

  MS_RLSD_ON
  0x0080

  The RLSD (receive-line-signal-detect) signal is on.