ATSerialFlowControl.cpp

00001 #include "mbed.h"
00002 #include "ATSerialFlowControl.h"
00003 #include "MTSLog.h"
00004 #include "Utils.h"
00005 
00006 using namespace mts;
00007 
00008 ATSerialFlowControl::ATSerialFlowControl(PinName TXD, PinName RXD, PinName RTS, PinName CTS, int txBufSize, int rxBufSize)
00009     : ATSerial(TXD, RXD, txBufSize, rxBufSize)
00010     , rxReadyFlag(false)
00011     , rts(RTS)
00012     , cts(CTS)
00013 {
00014     notifyStartSending();
00015 
00016     // Calculate the high and low watermark values
00017     highThreshold = mts_max(rxBufSize - 10, rxBufSize * 0.85);
00018     lowThreshold = rxBufSize * 0.3;
00019 
00020     // Setup the low watermark callback on the internal receive buffer
00021     rxBuffer.attach(this, &ATSerialFlowControl::notifyStartSending, lowThreshold, LESS);
00022 }
00023 
00024 ATSerialFlowControl::~ATSerialFlowControl()
00025 {
00026 }
00027 
00028 //Override the rxClear function to make sure that flow control lines are set correctly.
00029 void ATSerialFlowControl::rxClear()
00030 {
00031     MTSBufferedIO::rxClear();
00032     notifyStartSending();
00033 }
00034 
00035 void ATSerialFlowControl::notifyStartSending()
00036 {
00037     if(!rxReadyFlag) {
00038         rts.write(0);
00039         rxReadyFlag = true;
00040         //printf("RTS LOW: READY - RX[%d/%d]\r\n", rxBuffer.size(), rxBuffer.capacity());
00041     }
00042 }
00043 
00044 void ATSerialFlowControl::notifyStopSending()
00045 {
00046     if(rxReadyFlag) {
00047         rts.write(1);
00048         rxReadyFlag = false;
00049         //printf("RTS HIGH: NOT-READY - RX[%d/%d]\r\n", rxBuffer.size(), rxBuffer.capacity());
00050     }
00051 }
00052 
00053 void ATSerialFlowControl::handleRead()
00054 {
00055     ATSerial::handleRead();
00056     if (rxBuffer.size() >= highThreshold) {
00057         notifyStopSending();
00058     }
00059 }
00060 
00061 void ATSerialFlowControl::handleWrite()
00062 {
00063     while(txBuffer.size() != 0) {
00064         if (_serial->writeable() && cts.read() == 0) {
00065             char byte;
00066             if(txBuffer.read(byte) == 1) {
00067                 _serial->attach(NULL, Serial::RxIrq);
00068                 _serial->putc(byte);
00069                 _serial->attach(this, &ATSerialFlowControl::handleRead, Serial::RxIrq);
00070             }
00071         } else {
00072             return;
00073         }
00074     }
00075 }