ethernet shield code.txt

Creates either a Serial or EthernetServer called INTERFACE

then calls INTERFACE.print() in the code to send output 
to the USB port or the Network Shield

Connects with SPI port using the ICSP header. If the stack
of boards blocks or doesn't expose the SPI, you need jumpers
to the pins on the Uno/Mega

< grbba : that would still be true if the connectors aren't accessible. In a standard CommandStation stack 
< from bottom to top Mega , EthernetShield, motorShield that should not be the case

Pins Used:

Uno  - 10,11,12,13
Mega - 10,50,51,52,53 (53 isn't used but has to be kept as an output for SS)

< grbba: bleow that is a good question and i have no idea but would the SD card be the only one 
< conflicting in this case. Not so sure we shall take that on for now but see if someone comes 
< along with such an issue

Also, pin 4 is used by the SDCard

We disable the SDCard because it shares the same SPI bus and only the ethernet
chip or the SDCard can be active at any given time.

NOTE ABOUT LIBARIES - We need to re-investigate libraries since the Ethernet
                      library added support up to the W5500 chip. So we may
                      be able to use just one library

< grbba: The above is true today no need for muktiple libraries for Ethernet all Wiznet chips starting from
< 5100 up to the latest are ok only use the std Ethernet library from the Arduino framework

---------- In Config.h ------------

// 0 serial port
// 1 Arduino.cc shield (W5100, 16kb buffer)
// 2 Arduino.org shield
// 3 Seeed Studio W5200 shield



#define COMM_INTERFACE = 1

// uncomment for static IP, otherwise DHCP will assign it
// #define IP_ADDRESS { 192, 168, 1, 200 } 

#define ETHERNET_PORT 2560

< grbba: Port 2560 is taken by IBM fro a service called labrat :) so we should look for an unassigned port. I suggested 6988 as the int representaion of 'EX'
< and which is currently unassigned

// FlightRisk - I think we need this mode since newer boards have a MAC
//#if defined(WIZ550io_WITH_MACADDRESS) // Use assigned MAC address of WIZ550io
//;
//#else
//byte mac[] = {  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xEF }

#define MAC_ADDRESS {  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xEF }

< grbba: All the Ethernet Shields don't have a MAC burned into them so you have to make one up. The newer shields come with a sticker having the MAC
< allocated to them written on. It's an issue when you have the same MAC twice on the network. Obviously this is aserious security flaw but outside of our reach. 
< When only being on the local network no issue but if you run across the internet mileage may vary. 
< I added some generated ones in the comments of my implementation but as haba suggested we can derive one from the chip Id to make it fairly unique across 
< multiple CommandStations. Then even when having multiple commandstations on the nework it would be fine. 

--------- in comm.h --------------

#if COMM_TYPE == 1                 // Ethernet Shield Card Selected

  #if COMM_INTERFACE == 1
    #define COMM_SHIELD_NAME      "ARDUINO-CC ETHERNET SHIELD (WIZNET 5100)"
    #include <Ethernet.h>         // built-in Arduino.cc library

  #elif COMM_INTERFACE == 2
    #define COMM_SHIELD_NAME      "ARDUINO-ORG ETHERNET-2 SHIELD (WIZNET 5500)"
    #include <Ethernet2.h>        // https://github.com/arduino-org/Arduino

  #elif COMM_INTERFACE == 3
    #define COMM_SHIELD_NAME      "SEEED STUDIO ETHERNET SHIELD (WIZNET 5200)"
    #include <EthernetV2_0.h>     // https://github.com/Seeed-Studio/Ethernet_Shield_W5200

  #endif

  extern EthernetServer INTERFACE;
#endif 

< grbba: All of the above isn't neeed anymore

---------- in main.h --------------

#if COMM_INTERFACE == 0

  #define COMM_TYPE 0
  #define INTERFACE Serial

#elif (COMM_INTERFACE==1) || (COMM_INTERFACE==2) || (COMM_INTERFACE==3)

  #define COMM_TYPE 1
  #define INTERFACE eServer
  #define SDCARD_CS 4

#else
 
 #error Can't compile, select the right COMM_INTERFACE
 
 
< grbba: I actually detect presence/absence of the shield and/or wifi card at runtime and report an error if there is an issue but do not abort as i assume that
< in the worst case scenario you still would have serial bia serial monitor aviailble to issue commands if needed 

----------- in main.ino --------------

#if COMM_TYPE == 1
  byte mac[] =  MAC_ADDRESS;                                // Create MAC address (to be used for DHCP when initializing server)
  EthernetServer INTERFACE(ETHERNET_PORT);                  // Create and instance of an EnternetServer
#endif

void setup(){  

  #ifdef SDCARD_CS
    pinMode(SDCARD_CS,OUTPUT);
    digitalWrite(SDCARD_CS,HIGH);     // Deselect the SD card
  #endif

  #if COMM_TYPE == 1
    #ifdef IP_ADDRESS
      Ethernet.begin(mac,IP_ADDRESS);           // Start networking using STATIC IP Address
    #else
      // FlightRisk - Probably need "if Ethernet.begin(mac)== 0 then print "DHCP Failed"
      Ethernet.begin(mac);                      // Start networking using DHCP to get an IP Address
    #endif
    INTERFACE.begin();
  #endif
             
  < grbba: Yes indeed if DHCP fails you should ty to assign a fixed ip adress and see if you can connect this way. In any case the fixed IP address will
  < have to be edidted by the user according to his/her network config. My base address range e.g. is 10.0.x.y
  
        
  SerialCommand::init(&mainRegs, &progRegs, &mainMonitor);   // create structure to read and parse commands from serial line

  Serial.print("<N");
  Serial.print(COMM_TYPE);
  Serial.print(": ");

  #if COMM_TYPE == 0
    Serial.print("SERIAL>");
  #elif COMM_TYPE == 1
    Serial.print(Ethernet.localIP());
    Serial.print(">");
  #endif

  < grbba: All of the above is done by the parser : btw the parser doesn't validate if i just send a valid command without the < > brackets it gets 
  < executed and if i send something like 'stuff' <s> gets executed. Not an issue for the Arduino but on any other computer that is a mega security hole 
  < as it would allow e.g. for code injection etc.. or any other wierd things. On a smaller scale here as well you don't want any commandsting just 
  < create havoc on the system and make all you locos etc.. behave in a non determistic fashion :)
  < i will try and see what hapens if i send a 300char long arbitrary string to the commandStation ... 

} // setup


   #ifdef IP_ADDRESS
      Ethernet.begin(mac,IP_ADDRESS);           // Start networking using STATIC IP Address
   #else
      Ethernet.begin(mac);                      // Start networking using DHCP to get an IP Address
   #endif 

void(loop) {

serialCommand.process()

} // loop   

------------- in serialCommand.cpp ---------------

void SerialCommand::process(){
  char c;
    
  #if COMM_TYPE == 0

    while(INTERFACE.available()>0){    // while there is data on the serial line
     c=INTERFACE.read();
     if(c=='<')                    // start of new command
       sprintf(commandString,"");
     else if(c=='>')               // end of new command
       parse(commandString);                    
     else if(strlen(commandString)<MAX_COMMAND_LENGTH)    // if comandString still has space, append character just read from serial line
       sprintf(commandString,"%s%c",commandString,c);     // otherwise, character is ignored (but continue to look for '<' or '>')
    } // while
  
  #elif COMM_TYPE == 1

    EthernetClient client=INTERFACE.available();

    if(client){
      while(client.connected() && client.available()){        // while there is data on the network
      c=client.read();
      if(c=='<')                    // start of new command
        sprintf(commandString,"");
      else if(c=='>')               // end of new command
        parse(commandString);                    
      else if(strlen(commandString)<MAX_COMMAND_LENGTH)    // if comandString still has space, append character just read from network
        sprintf(commandString,"%s%c",commandString,c);     // otherwise, character is ignored (but continue to look for '<' or '>')
      } // while
    }

  #endif
  
  < grbba: one thing Gregg has ignored here is the fact that even the oldest cards have 4 socket connections available i.e. 4 simultaneous 
  < connections are possible the newer ones have 8. I added support for the max number of sockets and read from all of them. Well i never 
  < so far actually managed to get beyond 2 // connections so far but when you ramp up the connection load that could well be the case 
  < that you start using more of them

} // SerialCommand:process