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     , dtr(PA_11)
00014 {
00015     notifyStartSending();
00016 
00017     // Calculate the high and low watermark values
00018     highThreshold = mts_max(rxBufSize - 10, rxBufSize * 0.85);
00019     lowThreshold = rxBufSize * 0.3;
00020 
00021     // Setup the low watermark callback on the internal receive buffer
00022     rxBuffer.attach(this, &ATSerialFlowControl::notifyStartSending, lowThreshold, LESS);
00023 }
00024 
00025 ATSerialFlowControl::~ATSerialFlowControl()
00026 {
00027 }
00028 
00029 //Override the rxClear function to make sure that flow control lines are set correctly.
00030 void ATSerialFlowControl::rxClear()
00031 {
00032     MTSBufferedIO::rxClear();
00033     notifyStartSending();
00034 }
00035 
00036 void ATSerialFlowControl::notifyStartSending()
00037 {
00038     if(!rxReadyFlag) {
00039         rts.write(0);
00040         rxReadyFlag = true;
00041         //printf("RTS LOW: READY - RX[%d/%d]\r\n", rxBuffer.size(), rxBuffer.capacity());
00042     }
00043 }
00044 
00045 void ATSerialFlowControl::notifyStopSending()
00046 {
00047     if(rxReadyFlag) {
00048         rts.write(1);
00049         rxReadyFlag = false;
00050         //printf("RTS HIGH: NOT-READY - RX[%d/%d]\r\n", rxBuffer.size(), rxBuffer.capacity());
00051     }
00052 }
00053 
00054 void ATSerialFlowControl::handleRead()
00055 {
00056     ATSerial::handleRead();
00057     if (rxBuffer.size() >= highThreshold) {
00058         notifyStopSending();
00059     }
00060 }
00061 
00062 void ATSerialFlowControl::handleWrite()
00063 {  
00064      while(txBuffer.size() != 0) {        
00065         if (serial.writeable() && cts.read() == 0) {  
00066             dtr.write(0);                  
00067             char byte;
00068             if(txBuffer.read(byte) == 1) {
00069                 serial.attach(NULL, Serial::RxIrq);
00070                 serial.putc(byte);
00071                 serial.attach(this, &ATSerialFlowControl::handleRead, Serial::RxIrq);
00072             }
00073         } 
00074         else { 
00075             if (cts.read() == 1) dtr.write(1);             
00076             return;
00077         }
00078     }
00079 }
00080