I don't understand this IF statement for the TT case. It appears to me as a contradiction like IF (!A && A) which will never happen. However I've now seen this in 2 arduino ethernet examples, so it must work somehow. Please help me understand.
// if there's no net connection, but there was one last time
// through the loop, then stop the client:
if (!client.connected() && lastConnected) {
Serial.println();
Serial.println("disconnecting.");
client.stop();
}
// if you're not connected, and ten seconds have passed since
// your last connection, then connect again and send data:
if(!client.connected() && (millis() - lastConnectionTime > postingInterval)) {
sendData(sensorReading);
}
// store the state of the connection for next time through
// the loop:
lastConnected = client.connected();
}