reception of empty packets with and without callback (sandeepmistry#103)

* allows receiving empty packets with and without callback

* bug fix

* Update examples/CANReceiver/CANReceiver.ino

Co-authored-by: emekBaris <[email protected]>
Co-authored-by: Sandeep Mistry <[email protected]>

Author: 3 people

examples/CANReceiver/CANReceiver.ino

@@ -20,7 +20,7 @@ void loop() {
   // try to parse packet
   int packetSize = CAN.parsePacket();
 
-  if (packetSize) {
+  if (packetSize || CAN.packetId() != -1) {
     // received a packet
     Serial.print("Received ");
 

src/MCP2515.cpp

@@ -442,7 +442,7 @@ void MCP2515Class::handleInterrupt()
     return;
   }
 
-  while (parsePacket()) {
+  while (parsePacket() || _rxId != -1) {
     _onReceive(available());
   }
 }