我想用CH340做一個(gè)簡(jiǎn)單的工具，單片機(jī)和上位機(jī)通信，單片機(jī)除了和CH340通信，還可以傳遞出兩個(gè)低電平信號(hào)，我想用CH340得到這兩個(gè)低電平信號(hào)，但不知道上位機(jī)如何檢測(cè)到傳遞過(guò)來(lái)的信號(hào)，應(yīng)該用到的是CTS#和DSR#，請(qǐng)指導(dǎo)下在上位機(jī)程序中如何檢測(cè)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.