public void Transact(byte[] packetBodyOut, GPacketReceived packetIn)
{
//log("Transact --------------------------- started");
int tries = 0;
while(tries++ <= 3)
{
if(tries > 1)
{
logError("Transact - try " + tries);
}
Send(packetBodyOut);
TransFlag.Reset();
if (!TransFlag.WaitOne((int)TransTimeout, false))
{
logError("Transact - Timeout waiting for ACK");
if(tries == 3)
{
ThrowException("Timeout - check GPS cable and baud rate");
}
else
{
// just send the packet again
continue;
}
}
// analyze response, hopefully should be ACK (for our Send()):
if(rxPacket.RxPacketId != (int)BasicPids.Pid_Nak_Byte)
{
// if this is ACK, wait for the real packet to come.
// if not, assume we received the response packet
if(rxPacket.RxPacketId == (int)BasicPids.Pid_Ack_Byte)
{
//log("Transact - got ACK");
// receive actual response:
TransFlag.Reset();
if (!TransFlag.WaitOne((int)TransTimeout, false))
{
logError("Transact - Timeout");
if(tries == 3)
{
ThrowException("Timeout - check GPS cable and baud rate");
}
else
{
// just send the packet again
continue;
}
}
}
if(rxPacket.RxBadPacket)
{
logError("Transact - received bad packet - pid=" + rxPacket.RxPacketId);
continue;
}
else
{
//log("Transact - received good packet - pid=" + rxPacket.RxPacketId);
lock(rxPacket)
{
packetIn.isGood = !rxPacket.RxBadPacket;
packetIn.size = (int)rxPacket.RxBufferP;
packetIn.pid = rxPacket.RxPacketId;
packetIn.bytes = new byte[packetIn.size];
Array.Copy(rxPacket.RxBuffer, packetIn.bytes, packetIn.size);
}
rxPacket.Dispose();
break;
}
}
else // NAK
{
// just send the packet again
logError("Transact - got NAK for my packet (id=" + pidToString(packetBodyOut[0]) + ")");
continue;
}
/*
else
{
RxBufferP = 0;
logError("Transact - expected ACK for my packet (id=" + packetBodyOut[0] + ") -- came RxPacketId=" + RxPacketId);
// may be we missed ACK, instead next packet came.
}
*/
}
//log("Transact --------------------------- finished");
}
public void Receive(GPacketReceived packetIn)
{
//log("Receive() - waiting...");
TransFlag.Reset();
if (!TransFlag.WaitOne((int)TransTimeout, false))
{
string str = "Timeout: receive state=" + packetState;
if(arxPacket != null)
{
byte packetId = arxPacket.RxBuffer[0];
// packet body structure: byte[] { pid, count, ...data... }
string hdr = arxPacket.RxBufferP > 0 ? ("<" + pidToString(packetId) + ">") : "";
str += " received so far: " + hdr + " RxBufferP=" + arxPacket.RxBufferP + " :";
for(int i=1; i < arxPacket.RxBufferP && i < 20 ;i++)
{
str += " " + arxPacket.RxBuffer[i];
}
}
logError(str);
ThrowException("Timeout - check GPS cable and baud rate");
}
lock(rxPacket)
{
packetIn.isGood = !rxPacket.RxBadPacket;
packetIn.pid = rxPacket.RxPacketId;
packetIn.size = (int)rxPacket.RxBufferP;
packetIn.bytes = new byte[packetIn.size];
Array.Copy(rxPacket.RxBuffer, packetIn.bytes, packetIn.size);
}
rxPacket.Dispose();
//log("Receive() - received good packet - pid=" + packetIn.pid);
}
