Diff: MTSSerialFlowControl.h

Revision:

1:d34b566d6f47

Parent:

0:6585b7c8cd41

Child:

4:d348d001283b

--- a/MTSSerialFlowControl.h	Thu May 15 22:07:16 2014 +0000
+++ b/MTSSerialFlowControl.h	Mon May 19 11:18:10 2014 -0500
@@ -1,4 +1,62 @@
 #ifndef MTSSERIALFLOWCONTROL_H
 #define MTSSERIALFLOWCONTROL_H
 
-#endif
\ No newline at end of file
+#include "mbed.h"
+#include "MTSSerial.h"
+
+
+namespace mts
+{
+
+/** This class derives from MTSBufferedIO/MTSSerial and provides a buffered wrapper to the
+* standard mbed Serial class along with generic RTS/CTS HW flow control. Since it
+* depends only on the mbed Serial, DigitalOut and DigitalIn classes for accessing
+* the serial data, this class is inherently portable accross different mbed platforms
+* and provides HW flow control even when not natively supported by the processors
+* serial port. If HW flow control is not needed, use MTSSerial instead. It should also
+* be noted that the RTS/CTS functionality in this class is implemented as a DTE device.
+*/
+class MTSSerialFlowControl : public MTSSerial
+{
+public:
+    /** Creates a new MTSSerialFlowControl object that can be used to talk to an mbed serial
+    * port through internal SW buffers. Note that this class also adds the ability to use
+    * RTS/CTS HW Flow Conrtol through and standard mbed DigitalIn and DigitalOut pins.
+    * The RTS and CTS functionality assumes this is a DTE device.
+    *
+    * @param TXD the transmit data pin on the desired mbed serial interface.
+    * @param RXD the receive data pin on the desired mbed serial interface.
+    * @param RTS the DigitalOut pin that RTS will be attached to. (DTE)
+    * @param CTS the DigitalIn pin that CTS will be attached to. (DTE)
+    * @param txBufferSize the size in bytes of the internal SW transmit buffer. The
+    * default is 256 bytes.
+    * @param rxBufferSize the size in bytes of the internal SW receive buffer. The
+    * default is 256 bytes.
+    */
+    MTSSerialFlowControl(PinName TXD, PinName RXD, PinName RTS, PinName CTS, int txBufSize = 256, int rxBufSize = 256);
+
+    /** Destructs an MTSSerialFlowControl object and frees all related resources.
+    */
+    ~MTSSerialFlowControl();
+    
+    //Overriden from MTSBufferedIO to support flow control correctly
+    virtual void rxClear();
+
+private:
+    void notifyStartSending(); // Used to set cts start signal
+    void notifyStopSending(); // Used to set cts stop signal
+    
+    //This device acts as a DTE
+    bool rxReadyFlag;   //Tracks state change for rts signaling
+    DigitalOut rts; // Used to tell DCE to send or not send data
+    DigitalIn cts; // Used to check if DCE is ready for data
+    int highThreshold; // High water mark for setting cts to stop
+    int lowThreshold; // Low water mark for setting cts to start
+
+    virtual void handleRead(); // Method for handling data to be read
+    virtual void handleWrite(); // Method for handling data to be written
+};
+
+}
+
+#endif /* MTSSERIALFLOWCONTROL */