Diff: MTSSerialFlowControl.cpp

Revision:

1:d34b566d6f47

Child:

3:8e3cb3371b09

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MTSSerialFlowControl.cpp	Mon May 19 11:18:10 2014 -0500
@@ -0,0 +1,79 @@
+#include "MTSSerialFlowControl.h"
+
+#include "MTSLog.h"
+#include "Vars.h"
+
+using namespace mts;
+
+MTSSerialFlowControl::MTSSerialFlowControl(PinName TXD, PinName RXD, PinName RTS, PinName CTS, int txBufSize, int rxBufSize)
+    : MTSSerial(TXD, RXD, txBufSize, rxBufSize)
+    , rxReadyFlag(false)
+    , rts(RTS)
+    , cts(CTS)
+{
+    notifyStartSending();
+
+    // Calculate the high and low watermark values
+    highThreshold = MAX(rxBufSize - 10, rxBufSize * 0.85);
+    lowThreshold = rxBufSize * 0.3;
+
+    // Setup the low watermark callback on the internal receive buffer
+    rxBuffer.attach(this, &MTSSerialFlowControl::notifyStartSending, lowThreshold, LESS);
+}
+
+MTSSerialFlowControl::~MTSSerialFlowControl()
+{
+}
+
+//Override the rxClear function to make sure that flow control lines are set correctly.
+void MTSSerialFlowControl::rxClear()
+{
+    MTSBufferedIO::rxClear();
+    notifyStartSending();
+}
+
+void MTSSerialFlowControl::notifyStartSending()
+{
+    if(!rxReadyFlag) {
+        rts.write(0);
+        rxReadyFlag = true;
+        //printf("RTS LOW: READY - RX[%d/%d]\r\n", rxBuffer.size(), rxBuffer.capacity());
+    }
+}
+
+void MTSSerialFlowControl::notifyStopSending()
+{
+    if(rxReadyFlag) {
+        rts.write(1);
+        rxReadyFlag = false;
+        //printf("RTS HIGH: NOT-READY - RX[%d/%d]\r\n", rxBuffer.size(), rxBuffer.capacity());
+    }
+}
+
+void MTSSerialFlowControl::handleRead()
+{
+    char byte = serial.getc();
+    if(rxBuffer.write(byte) != 1) {
+        logError("Serial Rx Byte Dropped [%c][0x%02X]", byte, byte);
+    }
+    if (rxBuffer.size() >= highThreshold) {
+        notifyStopSending();
+    }
+}
+
+void MTSSerialFlowControl::handleWrite()
+{
+    while(txBuffer.size() != 0) {
+        if (serial.writeable() && cts.read() == 0) {
+            char byte;
+            if(txBuffer.read(byte) == 1) {
+                serial.attach(NULL, Serial::RxIrq);
+                serial.putc(byte);
+                serial.attach(this, &MTSSerialFlowControl::handleRead, Serial::RxIrq);
+            }
+        } else {
+            return;
+        }
+    }
+}
+