Pre-merge upstream Arduino

19 files changed, 531 insertions, 148 deletions

diff --git a/libraries/Ethernet/Dhcp.cpp b/libraries/Ethernet/Dhcp.cpp
index 62bbfeb..e4d27f7 100755
--- a/libraries/Ethernet/Dhcp.cpp
+++ b/libraries/Ethernet/Dhcp.cpp
@@ -11,13 +11,33 @@
 

 int DhcpClass::beginWithDHCP(uint8_t *mac, unsigned long timeout, unsigned long responseTimeout)

 {

-    uint8_t dhcp_state = STATE_DHCP_START;

-    uint8_t messageType = 0;

-  

-    // zero out _dhcpMacAddr, _dhcpSubnetMask, _dhcpGatewayIp, _dhcpLocalIp, _dhcpDhcpServerIp, _dhcpDnsServerIp

-    memset(_dhcpMacAddr, 0, 26); 

+    _dhcpLeaseTime=0;

+    _dhcpT1=0;

+    _dhcpT2=0;

+    _lastCheck=0;

+    _timeout = timeout;

+    _responseTimeout = responseTimeout;

+

+    // zero out _dhcpMacAddr

+    memset(_dhcpMacAddr, 0, 6); 

+    reset_DHCP_lease();

 

     memcpy((void*)_dhcpMacAddr, (void*)mac, 6);

+    _dhcp_state = STATE_DHCP_START;

+    return request_DHCP_lease();

+}

+

+void DhcpClass::reset_DHCP_lease(){

+    // zero out _dhcpSubnetMask, _dhcpGatewayIp, _dhcpLocalIp, _dhcpDhcpServerIp, _dhcpDnsServerIp

+    memset(_dhcpLocalIp, 0, 20);

+}

+

+//return:0 on error, 1 if request is sent and response is received

+int DhcpClass::request_DHCP_lease(){

+    

+    uint8_t messageType = 0;

+  

+    

   

     // Pick an initial transaction ID

     _dhcpTransactionId = random(1UL, 2000UL);

@@ -35,55 +55,75 @@ int DhcpClass::beginWithDHCP(uint8_t *mac, unsigned long timeout, unsigned long
     

     unsigned long startTime = millis();

     

-    while(dhcp_state != STATE_DHCP_LEASED)

+    while(_dhcp_state != STATE_DHCP_LEASED)

     {

-        if(dhcp_state == STATE_DHCP_START)

+        if(_dhcp_state == STATE_DHCP_START)

         {

             _dhcpTransactionId++;

             

             send_DHCP_MESSAGE(DHCP_DISCOVER, ((millis() - startTime) / 1000));

-            dhcp_state = STATE_DHCP_DISCOVER;

+            _dhcp_state = STATE_DHCP_DISCOVER;

+        }

+        else if(_dhcp_state == STATE_DHCP_REREQUEST){

+            _dhcpTransactionId++;

+            send_DHCP_MESSAGE(DHCP_REQUEST, ((millis() - startTime)/1000));

+            _dhcp_state = STATE_DHCP_REQUEST;

         }

-        else if(dhcp_state == STATE_DHCP_DISCOVER)

+        else if(_dhcp_state == STATE_DHCP_DISCOVER)

         {

             uint32_t respId;

-            messageType = parseDHCPResponse(responseTimeout, respId);

+            messageType = parseDHCPResponse(_responseTimeout, respId);

             if(messageType == DHCP_OFFER)

             {

                 // We'll use the transaction ID that the offer came with,

                 // rather than the one we were up to

                 _dhcpTransactionId = respId;

                 send_DHCP_MESSAGE(DHCP_REQUEST, ((millis() - startTime) / 1000));

-                dhcp_state = STATE_DHCP_REQUEST;

+                _dhcp_state = STATE_DHCP_REQUEST;

             }

         }

-        else if(dhcp_state == STATE_DHCP_REQUEST)

+        else if(_dhcp_state == STATE_DHCP_REQUEST)

         {

             uint32_t respId;

-            messageType = parseDHCPResponse(responseTimeout, respId);

+            messageType = parseDHCPResponse(_responseTimeout, respId);

             if(messageType == DHCP_ACK)

             {

-                dhcp_state = STATE_DHCP_LEASED;

+                _dhcp_state = STATE_DHCP_LEASED;

                 result = 1;

+                //use default lease time if we didn't get it

+                if(_dhcpLeaseTime == 0){

+                    _dhcpLeaseTime = DEFAULT_LEASE;

+                }

+                //calculate T1 & T2 if we didn't get it

+                if(_dhcpT1 == 0){

+                    //T1 should be 50% of _dhcpLeaseTime

+                    _dhcpT1 = _dhcpLeaseTime >> 1;

+                }

+                if(_dhcpT2 == 0){

+                    //T2 should be 87.5% (7/8ths) of _dhcpLeaseTime

+                    _dhcpT2 = _dhcpT1 << 1;

+                }

+                _renewInSec = _dhcpT1;

+                _rebindInSec = _dhcpT2;

             }

             else if(messageType == DHCP_NAK)

-                dhcp_state = STATE_DHCP_START;

+                _dhcp_state = STATE_DHCP_START;

         }

         

         if(messageType == 255)

         {

             messageType = 0;

-            dhcp_state = STATE_DHCP_START;

+            _dhcp_state = STATE_DHCP_START;

         }

         

-        if(result != 1 && ((millis() - startTime) > timeout))

+        if(result != 1 && ((millis() - startTime) > _timeout))

             break;

     }

     

     // We're done with the socket now

     _dhcpUdpSocket.stop();

     _dhcpTransactionId++;

-    

+

     return result;

 }

 

@@ -302,8 +342,26 @@ uint8_t DhcpClass::parseDHCPResponse(unsigned long responseTimeout, uint32_t& tr
                         }

                     }

                     break;

-                

+

+                case dhcpT1value : 

+                    opt_len = _dhcpUdpSocket.read();

+                    _dhcpUdpSocket.read((uint8_t*)&_dhcpT1, sizeof(_dhcpT1));

+                    _dhcpT1 = ntohl(_dhcpT1);

+                    break;

+

+                case dhcpT2value : 

+                    opt_len = _dhcpUdpSocket.read();

+                    _dhcpUdpSocket.read((uint8_t*)&_dhcpT2, sizeof(_dhcpT2));

+                    _dhcpT2 = ntohl(_dhcpT2);

+                    break;

+

                 case dhcpIPaddrLeaseTime :

+                    opt_len = _dhcpUdpSocket.read();

+                    _dhcpUdpSocket.read((uint8_t*)&_dhcpLeaseTime, sizeof(_dhcpLeaseTime));

+                    _dhcpLeaseTime = ntohl(_dhcpLeaseTime);

+                    _renewInSec = _dhcpLeaseTime;

+                    break;

+

                 default :

                     opt_len = _dhcpUdpSocket.read();

                     // Skip over the rest of this option

@@ -322,6 +380,68 @@ uint8_t DhcpClass::parseDHCPResponse(unsigned long responseTimeout, uint32_t& tr
     return type;

 }

 

+

+/*

+    returns:

+    0/DHCP_CHECK_NONE: nothing happened

+    1/DHCP_CHECK_RENEW_FAIL: renew failed

+    2/DHCP_CHECK_RENEW_OK: renew success

+    3/DHCP_CHECK_REBIND_FAIL: rebind fail

+    4/DHCP_CHECK_REBIND_OK: rebind success

+*/

+int DhcpClass::checkLease(){

+    //this uses a signed / unsigned trick to deal with millis overflow

+    unsigned long now = millis();

+    signed long snow = (long)now;

+    int rc=DHCP_CHECK_NONE;

+    if (_lastCheck != 0){

+        signed long factor;

+        //calc how many ms past the timeout we are

+        factor = snow - (long)_secTimeout;

+        //if on or passed the timeout, reduce the counters

+        if ( factor >= 0 ){

+            //next timeout should be now plus 1000 ms minus parts of second in factor

+            _secTimeout = snow + 1000 - factor % 1000;

+            //how many seconds late are we, minimum 1

+            factor = factor / 1000 +1;

+            

+            //reduce the counters by that mouch

+            //if we can assume that the cycle time (factor) is fairly constant

+            //and if the remainder is less than cycle time * 2 

+            //do it early instead of late

+            if(_renewInSec < factor*2 )

+                _renewInSec = 0;

+            else

+                _renewInSec -= factor;

+            

+            if(_rebindInSec < factor*2 )

+                _rebindInSec = 0;

+            else

+                _rebindInSec -= factor;

+        }

+

+        //if we have a lease but should renew, do it

+        if (_dhcp_state == STATE_DHCP_LEASED && _renewInSec <=0){

+            _dhcp_state = STATE_DHCP_REREQUEST;

+            rc = 1 + request_DHCP_lease();

+        }

+

+        //if we have a lease or is renewing but should bind, do it

+        if( (_dhcp_state == STATE_DHCP_LEASED || _dhcp_state == STATE_DHCP_START) && _rebindInSec <=0){

+            //this should basically restart completely

+            _dhcp_state = STATE_DHCP_START;

+            reset_DHCP_lease();

+            rc = 3 + request_DHCP_lease();

+        }

+    }

+    else{

+        _secTimeout = snow + 1000;

+    }

+

+    _lastCheck = now;

+    return rc;

+}

+

 IPAddress DhcpClass::getLocalIp()

 {

     return IPAddress(_dhcpLocalIp);

diff --git a/libraries/Ethernet/Dhcp.h b/libraries/Ethernet/Dhcp.h
index 149876d..4a47936 100755
--- a/libraries/Ethernet/Dhcp.h
+++ b/libraries/Ethernet/Dhcp.h
@@ -45,6 +45,13 @@
 #define MAX_DHCP_OPT	16

 

 #define HOST_NAME "WIZnet"

+#define DEFAULT_LEASE	(900) //default lease time in seconds

+

+#define DHCP_CHECK_NONE         (0)

+#define DHCP_CHECK_RENEW_FAIL   (1)

+#define DHCP_CHECK_RENEW_OK     (2)

+#define DHCP_CHECK_REBIND_FAIL  (3)

+#define DHCP_CHECK_REBIND_OK    (4)

 

 enum

 {

@@ -139,8 +146,19 @@ private:
   uint8_t  _dhcpGatewayIp[4];

   uint8_t  _dhcpDhcpServerIp[4];

   uint8_t  _dhcpDnsServerIp[4];

+  uint32_t _dhcpLeaseTime;

+  uint32_t _dhcpT1, _dhcpT2;

+  signed long _renewInSec;

+  signed long _rebindInSec;

+  signed long _lastCheck;

+  unsigned long _timeout;

+  unsigned long _responseTimeout;

+  unsigned long _secTimeout;

+  uint8_t _dhcp_state;

   EthernetUDP _dhcpUdpSocket;

   

+  int request_DHCP_lease();

+  void reset_DHCP_lease();

   void presend_DHCP();

   void send_DHCP_MESSAGE(uint8_t, uint16_t);

   void printByte(char *, uint8_t);

@@ -154,6 +172,7 @@ public:
   IPAddress getDnsServerIp();

   

   int beginWithDHCP(uint8_t *, unsigned long timeout = 60000, unsigned long responseTimeout = 4000);

+  int checkLease();

 };

 

 #endif

diff --git a/libraries/Ethernet/Ethernet.cpp b/libraries/Ethernet/Ethernet.cpp
index c298f3d..5d28f71 100644
--- a/libraries/Ethernet/Ethernet.cpp
+++ b/libraries/Ethernet/Ethernet.cpp
@@ -10,7 +10,8 @@ uint16_t EthernetClass::_server_port[MAX_SOCK_NUM] = {
 
 int EthernetClass::begin(uint8_t *mac_address)
 {
-  DhcpClass dhcp;
+  _dhcp = new DhcpClass();
+
 
   // Initialise the basic info
   W5100.init();
@@ -18,15 +19,15 @@ int EthernetClass::begin(uint8_t *mac_address)
   W5100.setIPAddress(IPAddress(0,0,0,0).raw_address());
 
   // Now try to get our config info from a DHCP server
-  int ret = dhcp.beginWithDHCP(mac_address);
+  int ret = _dhcp->beginWithDHCP(mac_address);
   if(ret == 1)
   {
     // We've successfully found a DHCP server and got our configuration info, so set things
     // accordingly
-    W5100.setIPAddress(dhcp.getLocalIp().raw_address());
-    W5100.setGatewayIp(dhcp.getGatewayIp().raw_address());
-    W5100.setSubnetMask(dhcp.getSubnetMask().raw_address());
-    _dnsServerAddress = dhcp.getDnsServerIp();
+    W5100.setIPAddress(_dhcp->getLocalIp().raw_address());
+    W5100.setGatewayIp(_dhcp->getGatewayIp().raw_address());
+    W5100.setSubnetMask(_dhcp->getSubnetMask().raw_address());
+    _dnsServerAddress = _dhcp->getDnsServerIp();
   }
 
   return ret;
@@ -66,6 +67,31 @@ void EthernetClass::begin(uint8_t *mac, IPAddress local_ip, IPAddress dns_server
   _dnsServerAddress = dns_server;
 }
 
+int EthernetClass::maintain(){
+  int rc = DHCP_CHECK_NONE;
+  if(_dhcp != NULL){
+    //we have a pointer to dhcp, use it
+    rc = _dhcp->checkLease();
+    switch ( rc ){
+      case DHCP_CHECK_NONE:
+        //nothing done
+        break;
+      case DHCP_CHECK_RENEW_OK:
+      case DHCP_CHECK_REBIND_OK:
+        //we might have got a new IP.
+        W5100.setIPAddress(_dhcp->getLocalIp().raw_address());
+        W5100.setGatewayIp(_dhcp->getGatewayIp().raw_address());
+        W5100.setSubnetMask(_dhcp->getSubnetMask().raw_address());
+        _dnsServerAddress = _dhcp->getDnsServerIp();
+        break;
+      default:
+        //this is actually a error, it will retry though
+        break;
+    }
+  }
+  return rc;
+}
+
 IPAddress EthernetClass::localIP()
 {
   IPAddress ret;
diff --git a/libraries/Ethernet/Ethernet.h b/libraries/Ethernet/Ethernet.h
index c916dda..2a07ff3 100644
--- a/libraries/Ethernet/Ethernet.h
+++ b/libraries/Ethernet/Ethernet.h
@@ -6,12 +6,14 @@
 #include "IPAddress.h"
 #include "EthernetClient.h"
 #include "EthernetServer.h"
+#include "Dhcp.h"
 
 #define MAX_SOCK_NUM 4
 
 class EthernetClass {
 private:
   IPAddress _dnsServerAddress;
+  DhcpClass* _dhcp;
 public:
   static uint8_t _state[MAX_SOCK_NUM];
   static uint16_t _server_port[MAX_SOCK_NUM];
@@ -23,6 +25,7 @@ public:
   void begin(uint8_t *mac_address, IPAddress local_ip, IPAddress dns_server);
   void begin(uint8_t *mac_address, IPAddress local_ip, IPAddress dns_server, IPAddress gateway);
   void begin(uint8_t *mac_address, IPAddress local_ip, IPAddress dns_server, IPAddress gateway, IPAddress subnet);
+  int maintain();
 
   IPAddress localIP();
   IPAddress subnetMask();
diff --git a/libraries/Ethernet/EthernetClient.cpp b/libraries/Ethernet/EthernetClient.cpp
index a77a62b..9885efb 100644
--- a/libraries/Ethernet/EthernetClient.cpp
+++ b/libraries/Ethernet/EthernetClient.cpp
@@ -41,7 +41,7 @@ int EthernetClient::connect(IPAddress ip, uint16_t port) {
 
   for (int i = 0; i < MAX_SOCK_NUM; i++) {
     uint8_t s = W5100.readSnSR(i);
-    if (s == SnSR::CLOSED || s == SnSR::FIN_WAIT) {
+    if (s == SnSR::CLOSED || s == SnSR::FIN_WAIT || s == SnSR::CLOSE_WAIT) {
       _sock = i;
       break;
     }
diff --git a/libraries/Ethernet/EthernetUdp.cpp b/libraries/Ethernet/EthernetUdp.cpp
index 9c752fc..3760052 100644
--- a/libraries/Ethernet/EthernetUdp.cpp
+++ b/libraries/Ethernet/EthernetUdp.cpp
@@ -52,15 +52,16 @@ uint8_t EthernetUDP::begin(uint16_t port) {
     return 0;
 
   _port = port;
+  _remaining = 0;
   socket(_sock, SnMR::UDP, _port, 0);
 
   return 1;
 }
 
-/* Is data available in rx buffer? Returns 0 if no, number of available bytes if yes. 
- * returned value includes 8 byte UDP header!*/
+/* return number of bytes available in the current packet,
+   will return zero if parsePacket hasn't been called yet */
 int EthernetUDP::available() {
-  return W5100.getRXReceivedSize(_sock);
+  return _remaining;
 }
 
 /* Release any resources being used by this EthernetUDP instance */
@@ -116,11 +117,14 @@ size_t EthernetUDP::write(const uint8_t *buffer, size_t size)
 
 int EthernetUDP::parsePacket()
 {
-  if (available() > 0)
+  // discard any remaining bytes in the last packet
+  flush();
+
+  if (W5100.getRXReceivedSize(_sock) > 0)
   {
     //HACK - hand-parse the UDP packet using TCP recv method
     uint8_t tmpBuf[8];
-    int ret =0;	
+    int ret =0; 
     //read 8 header bytes and get IP and port from it
     ret = recv(_sock,tmpBuf,8);
     if (ret > 0)
@@ -128,8 +132,11 @@ int EthernetUDP::parsePacket()
       _remoteIP = tmpBuf;
       _remotePort = tmpBuf[4];
       _remotePort = (_remotePort << 8) + tmpBuf[5];
+      _remaining = tmpBuf[6];
+      _remaining = (_remaining << 8) + tmpBuf[7];
+
       // When we get here, any remaining bytes are the data
-      ret = available();
+      ret = _remaining;
     }
     return ret;
   }
@@ -140,34 +147,58 @@ int EthernetUDP::parsePacket()
 int EthernetUDP::read()
 {
   uint8_t byte;
-  if (recv(_sock, &byte, 1) > 0)
+
+  if ((_remaining > 0) && (recv(_sock, &byte, 1) > 0))
   {
     // We read things without any problems
+    _remaining--;
     return byte;
   }
+
   // If we get here, there's no data available
   return -1;
 }
 
 int EthernetUDP::read(unsigned char* buffer, size_t len)
 {
-  /* In the readPacket that copes with truncating packets, the buffer was
-     filled with this code.  Not sure why it loops round reading out a byte
-     at a time.
-  int i;
-  for(i=0;i<(int)bufLen;i++) {
-    recv(_sock,tmpBuf,1);
-    buf[i]=tmpBuf[0];
+
+  if (_remaining > 0)
+  {
+
+    int got;
+
+    if (_remaining <= len)
+    {
+      // data should fit in the buffer
+      got = recv(_sock, buffer, _remaining);
+    }
+    else
+    {
+      // too much data for the buffer, 
+      // grab as much as will fit
+      got = recv(_sock, buffer, len);
+    }
+
+    if (got > 0)
+    {
+      _remaining -= got;
+      return got;
+    }
+
   }
-  */
-  return recv(_sock, buffer, len);
+
+  // If we get here, there's no data available or recv failed
+  return -1;
+
 }
 
 int EthernetUDP::peek()
 {
   uint8_t b;
-  // Unlike recv, peek doesn't check to see if there's any data available, so we must
-  if (!available())
+  // Unlike recv, peek doesn't check to see if there's any data available, so we must.
+  // If the user hasn't called parsePacket yet then return nothing otherwise they
+  // may get the UDP header
+  if (!_remaining)
     return -1;
   ::peek(_sock, &b);
   return b;
@@ -175,7 +206,11 @@ int EthernetUDP::peek()
 
 void EthernetUDP::flush()
 {
-  while (available())
+  // could this fail (loop endlessly) if _remaining > 0 and recv in read fails?
+  // should only occur if recv fails after telling us the data is there, lets
+  // hope the w5100 always behaves :)
+
+  while (_remaining)
   {
     read();
   }
diff --git a/libraries/Ethernet/EthernetUdp.h b/libraries/Ethernet/EthernetUdp.h
index 9a2b653..8a6b7ab 100644
--- a/libraries/Ethernet/EthernetUdp.h
+++ b/libraries/Ethernet/EthernetUdp.h
@@ -48,6 +48,7 @@ private:
   IPAddress _remoteIP; // remote IP address for the incoming packet whilst it's being processed
   uint16_t _remotePort; // remote port for the incoming packet whilst it's being processed
   uint16_t _offset; // offset into the packet being sent
+  uint16_t _remaining; // remaining bytes of incoming packet yet to be processed
 
 public:
   EthernetUDP();  // Constructor
diff --git a/libraries/Ethernet/examples/ChatServer/ChatServer.ino b/libraries/Ethernet/examples/ChatServer/ChatServer.ino
index 9f819fd..de75257 100644
--- a/libraries/Ethernet/examples/ChatServer/ChatServer.ino
+++ b/libraries/Ethernet/examples/ChatServer/ChatServer.ino
@@ -12,7 +12,7 @@
  
  created 18 Dec 2009
  by David A. Mellis
- modified 10 August 2010
+ modified 12 March 2012
  by Tom Igoe
  
  */
@@ -23,14 +23,16 @@
 // Enter a MAC address and IP address for your controller below.
 // The IP address will be dependent on your local network.
 // gateway and subnet are optional:
-byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
+byte mac[] = { 
+  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
 IPAddress ip(192,168,1, 177);
 IPAddress gateway(192,168,1, 1);
 IPAddress subnet(255, 255, 0, 0);
 
+
 // telnet defaults to port 23
 EthernetServer server(23);
-boolean gotAMessage = false; // whether or not you got a message from the client yet
+boolean alreadyConnected = false; // whether or not the client was connected previously
 
 void setup() {
   // initialize the ethernet device
@@ -39,25 +41,34 @@ void setup() {
   server.begin();
   // open the serial port
   Serial.begin(9600);
+  Serial.print("Chat server address:");
+  Serial.println(Ethernet.localIP());
 }
 
 void loop() {
   // wait for a new client:
   EthernetClient client = server.available();
-  
+
   // when the client sends the first byte, say hello:
   if (client) {
-    if (!gotAMessage) {
+    if (!alreadyConnected) {
+      // clead out the input buffer:
+      client.flush();    
       Serial.println("We have a new client");
       client.println("Hello, client!"); 
-      gotAMessage = true;
+      alreadyConnected = true;
+    } 
+
+    if (client.available() > 0) {
+      // read the bytes incoming from the client:
+      char thisChar = client.read();
+      // echo the bytes back to the client:
+      server.write(thisChar);
+      // echo the bytes to the server as well:
+      Serial.write(thisChar);
     }
-    
-    // read the bytes incoming from the client:
-    char thisChar = client.read();
-    // echo the bytes back to the client:
-    server.write(thisChar);
-    // echo the bytes to the server as well:
-    Serial.print(thisChar);
   }
 }
+
+
+
diff --git a/libraries/Ethernet/examples/PachubeClient/PachubeClient.ino b/libraries/Ethernet/examples/PachubeClient/PachubeClient.ino
index a169443..4d4290d 100644
--- a/libraries/Ethernet/examples/PachubeClient/PachubeClient.ino
+++ b/libraries/Ethernet/examples/PachubeClient/PachubeClient.ino
@@ -6,15 +6,20 @@
  the Adafruit Ethernet shield, either one will work, as long as it's got
  a Wiznet Ethernet module on board.
  
+ This example has been updated to use version 2.0 of the Pachube.com API. 
+ To make it work, create a feed with a datastream, and give it the ID
+ sensor1. Or change the code below to match your feed.
+ 
+ 
  Circuit:
  * Analog sensor attached to analog in 0
  * Ethernet shield attached to pins 10, 11, 12, 13
  
  created 15 March 2010
- updated 26 Oct 2011
- by Tom Igoe
+ updated 16 Mar 2012
+ by Tom Igoe with input from Usman Haque and Joe Saavedra
  
- http://www.tigoe.net/pcomp/code/category/arduinowiring/873
+http://arduino.cc/en/Tutorial/PachubeClient
  This code is in the public domain.
  
  */
@@ -22,6 +27,10 @@
 #include <SPI.h>
 #include <Ethernet.h>
 
+#define APIKEY         "YOUR API KEY GOES HERE" // replace your pachube api key here
+#define FEEDID         00000 // replace your feed ID
+#define USERAGENT      "My Project" // user agent is the project name
+
 // assign a MAC address for the ethernet controller.
 // Newer Ethernet shields have a MAC address printed on a sticker on the shield
 // fill in your address here:
@@ -34,26 +43,22 @@ IPAddress ip(10,0,1,20);
 // initialize the library instance:
 EthernetClient client;
 
-long lastConnectionTime = 0;        // last time you connected to the server, in milliseconds
-boolean lastConnected = false;      // state of the connection last time through the main loop
-const int postingInterval = 10000;  //delay between updates to Pachube.com
+// if you don't want to use DNS (and reduce your sketch size)
+// use the numeric IP instead of the name for the server:
+IPAddress server(216,52,233,122);      // numeric IP for api.pachube.com
+//char server[] = "api.pachube.com";   // name address for pachube API
+
+unsigned long lastConnectionTime = 0;          // last time you connected to the server, in milliseconds
+boolean lastConnected = false;                 // state of the connection last time through the main loop
+const unsigned long postingInterval = 10*1000; //delay between updates to Pachube.com
 
 void setup() {
   // start serial port:
   Serial.begin(9600);
-  // start the Ethernet connection:
+ // start the Ethernet connection:
   if (Ethernet.begin(mac) == 0) {
     Serial.println("Failed to configure Ethernet using DHCP");
-    // no point in carrying on, so do nothing forevermore:
-    for(;;)
-      ;
-  }
-  // give the ethernet module time to boot up:
-  delay(1000);
-  // start the Ethernet connection:
-  if (Ethernet.begin(mac) == 0) {
-    Serial.println("Failed to configure Ethernet using DHCP");
-    // Configure manually:
+    // DHCP failed, so use a fixed IP address:
     Ethernet.begin(mac, ip);
   }
 }
@@ -91,34 +96,43 @@ void loop() {
 // this method makes a HTTP connection to the server:
 void sendData(int thisData) {
   // if there's a successful connection:
-  if (client.connect("www.pachube.com", 80)) {
+  if (client.connect(server, 80)) {
     Serial.println("connecting...");
-    // send the HTTP PUT request. 
-    // fill in your feed address here:
-    client.print("PUT /api/YOUR_FEED_HERE.csv HTTP/1.1\n");
-    client.print("Host: www.pachube.com\n");
-    // fill in your Pachube API key here:
-    client.print("X-PachubeApiKey: YOUR_KEY_HERE\n");
+    // send the HTTP PUT request:
+    client.print("PUT /v2/feeds/");
+    client.print(FEEDID);
+    client.println(".csv HTTP/1.1");
+    client.println("Host: api.pachube.com");
+    client.print("X-PachubeApiKey: ");
+    client.println(APIKEY);
+    client.print("User-Agent: ");
+    client.println(USERAGENT);
     client.print("Content-Length: ");
 
     // calculate the length of the sensor reading in bytes:
-    int thisLength = getLength(thisData);
-    client.println(thisLength, DEC);
+    // 8 bytes for "sensor1," + number of digits of the data:
+    int thisLength = 8 + getLength(thisData);
+    client.println(thisLength);
 
     // last pieces of the HTTP PUT request:
-    client.print("Content-Type: text/csv\n");
-    client.println("Connection: close\n");
+    client.println("Content-Type: text/csv");
+    client.println("Connection: close");
+    client.println();
 
     // here's the actual content of the PUT request:
-    client.println(thisData, DEC);
-
-    // note the time that the connection was made:
-    lastConnectionTime = millis();
+    client.print("sensor1,");
+    client.println(thisData);
+  
   } 
   else {
     // if you couldn't make a connection:
     Serial.println("connection failed");
+    Serial.println();
+    Serial.println("disconnecting.");
+    client.stop();
   }
+   // note the time that the connection was made or attempted:
+  lastConnectionTime = millis();
 }
 
 
diff --git a/libraries/Ethernet/examples/PachubeClientString/PachubeClientString.ino b/libraries/Ethernet/examples/PachubeClientString/PachubeClientString.ino
index 4a03100..3535287 100644
--- a/libraries/Ethernet/examples/PachubeClientString/PachubeClientString.ino
+++ b/libraries/Ethernet/examples/PachubeClientString/PachubeClientString.ino
@@ -6,6 +6,10 @@
  the Adafruit Ethernet shield, either one will work, as long as it's got
  a Wiznet Ethernet module on board.
  
+ This example has been updated to use version 2.0 of the Pachube.com API. 
+ To make it work, create a feed with two datastreams, and give them the IDs
+ sensor1 and sensor2. Or change the code below to match your feed.
+ 
  This example uses the String library, which is part of the Arduino core from
  version 0019.  
  
@@ -14,9 +18,10 @@
  * Ethernet shield attached to pins 10, 11, 12, 13
  
  created 15 March 2010
- updated 26 Oct 2011
- by Tom Igoe
+ updated 16 Mar 2012
+ by Tom Igoe with input from Usman Haque and Joe Saavedra
  
+ http://arduino.cc/en/Tutorial/PachubeClientString
  This code is in the public domain.
  
  */
@@ -24,9 +29,14 @@
 #include <SPI.h>
 #include <Ethernet.h>
 
+
+#define APIKEY         "YOUR API KEY GOES HERE" // replace your pachube api key here
+#define FEEDID         00000 // replace your feed ID
+#define USERAGENT      "My Project" // user agent is the project name
+
 // assign a MAC address for the ethernet controller.
 // fill in your address here:
-byte mac[] = { 
+  byte mac[] = { 
   0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};
 // fill in an available IP address on your network here,
 // for manual configuration:
@@ -35,9 +45,14 @@ IPAddress ip(10,0,1,20);
 // initialize the library instance:
 EthernetClient client;
 
-long lastConnectionTime = 0;        // last time you connected to the server, in milliseconds
-boolean lastConnected = false;      // state of the connection last time through the main loop
-const int postingInterval = 10000;  //delay between updates to Pachube.com
+// if you don't want to use DNS (and reduce your sketch size)
+// use the numeric IP instead of the name for the server:
+//IPAddress server(216,52,233,122);      // numeric IP for api.pachube.com
+char server[] = "api.pachube.com";   // name address for pachube API
+
+unsigned long lastConnectionTime = 0;          // last time you connected to the server, in milliseconds
+boolean lastConnected = false;                 // state of the connection last time through the main loop
+const unsigned long postingInterval = 10*1000;  //delay between updates to Pachube.com
 
 void setup() {
   // start serial port:
@@ -47,7 +62,7 @@ void setup() {
   // start the Ethernet connection:
   if (Ethernet.begin(mac) == 0) {
     Serial.println("Failed to configure Ethernet using DHCP");
-    // Configure manually:
+    // DHCP failed, so use a fixed IP address:
     Ethernet.begin(mac, ip);
   }
 }
@@ -56,13 +71,15 @@ void loop() {
   // read the analog sensor:
   int sensorReading = analogRead(A0);   
   // convert the data to a String to send it:
-  String dataString = String(sensorReading);
+
+  String dataString = "sensor1,";
+  dataString += sensorReading;
 
   // you can append multiple readings to this String if your
   // pachube feed is set up to handle multiple values:
   int otherSensorReading = analogRead(A1);
-  dataString += ",";
-  dataString += String(otherSensorReading);
+  dataString += "\nsensor2,";
+  dataString += otherSensorReading;
 
   // if there's incoming data from the net connection.
   // send it out the serial port.  This is for debugging
@@ -81,7 +98,7 @@ void loop() {
   }
 
   // if you're not connected, and ten seconds have passed since
-  // your last connection, then connect again and send data:
+  // your last connection, then connect again and send data: 
   if(!client.connected() && (millis() - lastConnectionTime > postingInterval)) {
     sendData(dataString);
   }
@@ -93,29 +110,36 @@ void loop() {
 // this method makes a HTTP connection to the server:
 void sendData(String thisData) {
   // if there's a successful connection:
-  if (client.connect("www.pachube.com", 80)) {
+  if (client.connect(server, 80)) {
     Serial.println("connecting...");
-    // send the HTTP PUT request. 
-    // fill in your feed address here:
-    client.print("PUT /api/YOUR_FEED_HERE.csv HTTP/1.1\n");
-    client.print("Host: www.pachube.com\n");
-    // fill in your Pachube API key here:
-    client.print("X-PachubeApiKey: YOUR_KEY_HERE\n");
+    // send the HTTP PUT request:
+    client.print("PUT /v2/feeds/");
+    client.print(FEEDID);
+    client.println(".csv HTTP/1.1");
+    client.println("Host: api.pachube.com");
+    client.print("X-PachubeApiKey: ");
+    client.println(APIKEY);
+    client.print("User-Agent: ");
+    client.println(USERAGENT);
     client.print("Content-Length: ");
-    client.println(thisData.length(), DEC);
+    client.println(thisData.length());
 
     // last pieces of the HTTP PUT request:
-    client.print("Content-Type: text/csv\n");
-    client.println("Connection: close\n");
+    client.println("Content-Type: text/csv");
+    client.println("Connection: close");
+    client.println();
 
     // here's the actual content of the PUT request:
     client.println(thisData);
-
-    // note the time that the connection was made:
-    lastConnectionTime = millis();
   } 
   else {
     // if you couldn't make a connection:
     Serial.println("connection failed");
+    Serial.println();
+    Serial.println("disconnecting.");
+    client.stop();
   }
+  // note the time that the connection was made or attempted:
+  lastConnectionTime = millis();
 }
+
diff --git a/libraries/Ethernet/examples/TwitterClient/TwitterClient.ino b/libraries/Ethernet/examples/TwitterClient/TwitterClient.ino
index f113e17..a3b397d 100644
--- a/libraries/Ethernet/examples/TwitterClient/TwitterClient.ino
+++ b/libraries/Ethernet/examples/TwitterClient/TwitterClient.ino
@@ -14,7 +14,7 @@
  version 0019.  
  
  Circuit:
-  * Ethernet shield attached to pins 10, 11, 12, 13
+ * Ethernet shield attached to pins 10, 11, 12, 13
  
  created 21 May 2011
  by Tom Igoe
@@ -35,12 +35,12 @@ IPAddress ip(192,168,1,20);
 // initialize the library instance:
 EthernetClient client;
 
-const int requestInterval = 60000;  // delay between requests
+const unsigned long requestInterval = 60000;  // delay between requests
 
 char serverName[] = "api.twitter.com";  // twitter URL
 
 boolean requested;                   // whether you've made a request since connecting
-long lastAttemptTime = 0;            // last time you connected to the server, in milliseconds
+unsigned long lastAttemptTime = 0;            // last time you connected to the server, in milliseconds
 
 String currentLine = "";            // string to hold the text from server
 String tweet = "";                  // string to hold the tweet
@@ -51,13 +51,17 @@ void setup() {
   currentLine.reserve(256);
   tweet.reserve(150);
 
-// initialize serial:
+  // initialize serial:
   Serial.begin(9600);
   // attempt a DHCP connection:
+  Serial.println("Attempting to get an IP address using DHCP:");
   if (!Ethernet.begin(mac)) {
     // if DHCP fails, start with a hard-coded address:
+    Serial.println("failed to get an IP address using DHCP, trying manually");
     Ethernet.begin(mac, ip);
   }
+  Serial.print("My address:");
+  Serial.println(Ethernet.localIP());
   // connect to Twitter:
   connectToServer();
 }
@@ -114,7 +118,7 @@ void connectToServer() {
   Serial.println("connecting to server...");
   if (client.connect(serverName, 80)) {
     Serial.println("making HTTP request...");
-  // make HTTP GET request to twitter:
+    // make HTTP GET request to twitter:
     client.println("GET /1/statuses/user_timeline.xml?screen_name=arduino&count=1 HTTP/1.1");
     client.println("HOST: api.twitter.com");
     client.println();
@@ -122,3 +126,4 @@ void connectToServer() {
   // note the time of this connect attempt:
   lastAttemptTime = millis();
 }   
+
diff --git a/libraries/Ethernet/examples/WebServer/WebServer.ino b/libraries/Ethernet/examples/WebServer/WebServer.ino
index 6837f83..7cf2c53 100644
--- a/libraries/Ethernet/examples/WebServer/WebServer.ino
+++ b/libraries/Ethernet/examples/WebServer/WebServer.ino
@@ -10,7 +10,7 @@
  
  created 18 Dec 2009
  by David A. Mellis
- modified 4 Sep 2010
+ modified 20 Mar 2012
  by Tom Igoe
  
  */
@@ -20,7 +20,8 @@
 
 // Enter a MAC address and IP address for your controller below.
 // The IP address will be dependent on your local network:
-byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
+byte mac[] = { 
+  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
 IPAddress ip(192,168,1, 177);
 
 // Initialize the Ethernet server library
@@ -28,23 +29,27 @@ IPAddress ip(192,168,1, 177);
 // (port 80 is default for HTTP):
 EthernetServer server(80);
 
-void setup()
-{
+void setup() {
+  Serial.begin(9600);
   // start the Ethernet connection and the server:
   Ethernet.begin(mac, ip);
   server.begin();
+  Serial.print("server is at ");
+  Serial.println(Ethernet.localIP());
 }
 
-void loop()
-{
+
+void loop() {
   // listen for incoming clients
   EthernetClient client = server.available();
   if (client) {
+    Serial.println("new client");
     // an http request ends with a blank line
     boolean currentLineIsBlank = true;
     while (client.connected()) {
       if (client.available()) {
         char c = client.read();
+        Serial.write(c);
         // if you've gotten to the end of the line (received a newline
         // character) and the line is blank, the http request has ended,
         // so you can send a reply
@@ -52,16 +57,22 @@ void loop()
           // send a standard http response header
           client.println("HTTP/1.1 200 OK");
           client.println("Content-Type: text/html");
+          client.println("Connnection: close");
           client.println();
-
+          client.println("<!DOCTYPE HTML>");
+          client.println("<html>");
+                    // add a meta refresh tag, so the browser pulls again every 5 seconds:
+          client.println("<meta http-equiv=\"refresh\" content=\"5\">");
           // output the value of each analog input pin
           for (int analogChannel = 0; analogChannel < 6; analogChannel++) {
+            int sensorReading = analogRead(analogChannel);
             client.print("analog input ");
             client.print(analogChannel);
             client.print(" is ");
-            client.print(analogRead(analogChannel));
-            client.println("<br />");
+            client.print(sensorReading);
+            client.println("<br />");       
           }
+          client.println("</html>");
           break;
         }
         if (c == '\n') {
@@ -78,5 +89,7 @@ void loop()
     delay(1);
     // close the connection:
     client.stop();
+    Serial.println("client disonnected");
   }
 }
+
diff --git a/libraries/SD/utility/SdFatUtil.h b/libraries/SD/utility/SdFatUtil.h
index 283fcb2..7d6b410 100644
--- a/libraries/SD/utility/SdFatUtil.h
+++ b/libraries/SD/utility/SdFatUtil.h
@@ -56,7 +56,7 @@ static UNUSEDOK int FreeRam(void) {
  * \param[in] str Pointer to string stored in flash memory.

  */

 static NOINLINE void SerialPrint_P(PGM_P str) {

-  for (uint8_t c; (c = pgm_read_byte(str)); str++) Serial.print(c);

+  for (uint8_t c; (c = pgm_read_byte(str)); str++) Serial.write(c);

 }

 //------------------------------------------------------------------------------

 /**

diff --git a/libraries/Servo/Servo.cpp b/libraries/Servo/Servo.cpp
index acac29a..a716433 100755
--- a/libraries/Servo/Servo.cpp
+++ b/libraries/Servo/Servo.cpp
@@ -89,7 +89,7 @@ static inline void handle_interrupts(timer16_Sequence_t timer, volatile uint16_t
   }  

   else { 

     // finished all channels so wait for the refresh period to expire before starting over 

-    if( (unsigned)*TCNTn <  (usToTicks(REFRESH_INTERVAL) + 4) )  // allow a few ticks to ensure the next OCR1A not missed

+    if( ((unsigned)*TCNTn) + 4 < usToTicks(REFRESH_INTERVAL) )  // allow a few ticks to ensure the next OCR1A not missed

       *OCRnA = (unsigned int)usToTicks(REFRESH_INTERVAL);  

     else 

       *OCRnA = *TCNTn + 4;  // at least REFRESH_INTERVAL has elapsed

@@ -298,7 +298,7 @@ void Servo::writeMicroseconds(int value)
 {

   // calculate and store the values for the given channel

   byte channel = this->servoIndex;

-  if( (channel >= 0) && (channel < MAX_SERVOS) )   // ensure channel is valid

+  if( (channel < MAX_SERVOS) )   // ensure channel is valid

   {  

     if( value < SERVO_MIN() )          // ensure pulse width is valid

       value = SERVO_MIN();

diff --git a/libraries/SoftwareSerial/examples/SoftwareSerialExample/SoftwareSerialExample.ino b/libraries/SoftwareSerial/examples/SoftwareSerialExample/SoftwareSerialExample.ino
index 1f535bd..615d2b3 100644
--- a/libraries/SoftwareSerial/examples/SoftwareSerialExample/SoftwareSerialExample.ino
+++ b/libraries/SoftwareSerial/examples/SoftwareSerialExample/SoftwareSerialExample.ino
@@ -1,6 +1,23 @@
+/*
+  Software serial multple serial test
+ 
+ Receives from the hardware serial, sends to software serial.
+ Receives from software serial, sends to hardware serial.
+ 
+ The circuit: 
+ * RX is digital pin 2 (connect to TX of other device)
+ * TX is digital pin 3 (connect to RX of other device)
+ 
+ created back in the mists of time
+ by Tom Igoe
+ based on Mikal Hart's example
+ 
+ This example code is in the public domain.
+ 
+ */
 #include <SoftwareSerial.h>
 
-SoftwareSerial mySerial(2, 3);
+SoftwareSerial mySerial(2, 3); // RX, TX
 
 void setup()  
 {
diff --git a/libraries/Wire/Wire.cpp b/libraries/Wire/Wire.cpp
index d83f478..4e7a17c 100755
--- a/libraries/Wire/Wire.cpp
+++ b/libraries/Wire/Wire.cpp
@@ -15,6 +15,8 @@
   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ 
+  Modified 2012 by Todd Krein (todd@krein.org) to implement repeated starts
 */
 
 extern "C" {
@@ -73,14 +75,14 @@ void TwoWire::begin(int address)
   begin((uint8_t)address);
 }
 
-uint8_t TwoWire::requestFrom(uint8_t address, uint8_t quantity)
+uint8_t TwoWire::requestFrom(uint8_t address, uint8_t quantity, uint8_t sendStop)
 {
   // clamp to buffer length
   if(quantity > BUFFER_LENGTH){
     quantity = BUFFER_LENGTH;
   }
   // perform blocking read into buffer
-  uint8_t read = twi_readFrom(address, rxBuffer, quantity);
+  uint8_t read = twi_readFrom(address, rxBuffer, quantity, sendStop);
   // set rx buffer iterator vars
   rxBufferIndex = 0;
   rxBufferLength = read;
@@ -88,9 +90,19 @@ uint8_t TwoWire::requestFrom(uint8_t address, uint8_t quantity)
   return read;
 }
 
+uint8_t TwoWire::requestFrom(uint8_t address, uint8_t quantity)
+{
+  return requestFrom((uint8_t)address, (uint8_t)quantity, (uint8_t)true);
+}
+
 uint8_t TwoWire::requestFrom(int address, int quantity)
 {
-  return requestFrom((uint8_t)address, (uint8_t)quantity);
+  return requestFrom((uint8_t)address, (uint8_t)quantity, (uint8_t)true);
+}
+
+uint8_t TwoWire::requestFrom(int address, int quantity, int sendStop)
+{
+  return requestFrom((uint8_t)address, (uint8_t)quantity, (uint8_t)sendStop);
 }
 
 void TwoWire::beginTransmission(uint8_t address)
@@ -109,10 +121,23 @@ void TwoWire::beginTransmission(int address)
   beginTransmission((uint8_t)address);
 }
 
-uint8_t TwoWire::endTransmission(void)
+//
+//	Originally, 'endTransmission' was an f(void) function.
+//	It has been modified to take one parameter indicating
+//	whether or not a STOP should be performed on the bus.
+//	Calling endTransmission(false) allows a sketch to 
+//	perform a repeated start. 
+//
+//	WARNING: Nothing in the library keeps track of whether
+//	the bus tenure has been properly ended with a STOP. It
+//	is very possible to leave the bus in a hung state if
+//	no call to endTransmission(true) is made. Some I2C
+//	devices will behave oddly if they do not see a STOP.
+//
+uint8_t TwoWire::endTransmission(uint8_t sendStop)
 {
   // transmit buffer (blocking)
-  int8_t ret = twi_writeTo(txAddress, txBuffer, txBufferLength, 1);
+  int8_t ret = twi_writeTo(txAddress, txBuffer, txBufferLength, 1, sendStop);
   // reset tx buffer iterator vars
   txBufferIndex = 0;
   txBufferLength = 0;
@@ -121,6 +146,14 @@ uint8_t TwoWire::endTransmission(void)
   return ret;
 }
 
+//	This provides backwards compatibility with the original
+//	definition, and expected behaviour, of endTransmission
+//
+uint8_t TwoWire::endTransmission(void)
+{
+  return endTransmission(true);
+}
+
 // must be called in:
 // slave tx event callback
 // or after beginTransmission(address)
diff --git a/libraries/Wire/Wire.h b/libraries/Wire/Wire.h
index 9ea4afd..a93d0f5 100755
--- a/libraries/Wire/Wire.h
+++ b/libraries/Wire/Wire.h
@@ -15,6 +15,8 @@
   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+  Modified 2012 by Todd Krein (todd@krein.org) to implement repeated starts
 */
 
 #ifndef TwoWire_h
@@ -50,8 +52,11 @@ class TwoWire : public Stream
     void beginTransmission(uint8_t);
     void beginTransmission(int);
     uint8_t endTransmission(void);
+    uint8_t endTransmission(uint8_t);
     uint8_t requestFrom(uint8_t, uint8_t);
+    uint8_t requestFrom(uint8_t, uint8_t, uint8_t);
     uint8_t requestFrom(int, int);
+    uint8_t requestFrom(int, int, int);
     virtual size_t write(uint8_t);
     virtual size_t write(const uint8_t *, size_t);
     virtual int available(void);
diff --git a/libraries/Wire/utility/twi.c b/libraries/Wire/utility/twi.c
index d80114b..6b2db3c 100644
--- a/libraries/Wire/utility/twi.c
+++ b/libraries/Wire/utility/twi.c
@@ -15,6 +15,8 @@
   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+  Modified 2012 by Todd Krein (todd@krein.org) to implement repeated starts
 */
 
 #include <math.h>
@@ -37,14 +39,16 @@
 #include "twi.h"
 
 static volatile uint8_t twi_state;
-static uint8_t twi_slarw;
+static volatile uint8_t twi_slarw;
+static volatile uint8_t twi_sendStop;			// should the transaction end with a stop
+static volatile uint8_t twi_inRepStart;			// in the middle of a repeated start
 
 static void (*twi_onSlaveTransmit)(void);
 static void (*twi_onSlaveReceive)(uint8_t*, int);
 
 static uint8_t twi_masterBuffer[TWI_BUFFER_LENGTH];
 static volatile uint8_t twi_masterBufferIndex;
-static uint8_t twi_masterBufferLength;
+static volatile uint8_t twi_masterBufferLength;
 
 static uint8_t twi_txBuffer[TWI_BUFFER_LENGTH];
 static volatile uint8_t twi_txBufferIndex;
@@ -65,6 +69,8 @@ void twi_init(void)
 {
   // initialize state
   twi_state = TWI_READY;
+  twi_sendStop = true;		// default value
+  twi_inRepStart = false;
   
   // activate internal pullups for twi.
   digitalWrite(SDA, 1);
@@ -103,9 +109,10 @@ void twi_setAddress(uint8_t address)
  * Input    address: 7bit i2c device address
  *          data: pointer to byte array
  *          length: number of bytes to read into array
+ *          sendStop: Boolean indicating whether to send a stop at the end
  * Output   number of bytes read
  */
-uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length)
+uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length, uint8_t sendStop)
 {
   uint8_t i;
 
@@ -119,6 +126,7 @@ uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length)
     continue;
   }
   twi_state = TWI_MRX;
+  twi_sendStop = sendStop;
   // reset error state (0xFF.. no error occured)
   twi_error = 0xFF;
 
@@ -135,8 +143,20 @@ uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length)
   twi_slarw = TW_READ;
   twi_slarw |= address << 1;
 
-  // send start condition
-  TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTA);
+  if (true == twi_inRepStart) {
+    // if we're in the repeated start state, then we've already sent the start,
+    // (@@@ we hope), and the TWI statemachine is just waiting for the address byte.
+    // We need to remove ourselves from the repeated start state before we enable interrupts,
+    // since the ISR is ASYNC, and we could get confused if we hit the ISR before cleaning
+    // up. Also, don't enable the START interrupt. There may be one pending from the 
+    // repeated start that we sent outselves, and that would really confuse things.
+    twi_inRepStart = false;			// remember, we're dealing with an ASYNC ISR
+    TWDR = twi_slarw;
+    TWCR = _BV(TWINT) | _BV(TWEA) | _BV(TWEN) | _BV(TWIE);	// enable INTs, but not START
+  }
+  else
+    // send start condition
+    TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTA);
 
   // wait for read operation to complete
   while(TWI_MRX == twi_state){
@@ -162,13 +182,14 @@ uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length)
  *          data: pointer to byte array
  *          length: number of bytes in array
  *          wait: boolean indicating to wait for write or not
+ *          sendStop: boolean indicating whether or not to send a stop at the end
  * Output   0 .. success
  *          1 .. length to long for buffer
  *          2 .. address send, NACK received
  *          3 .. data send, NACK received
  *          4 .. other twi error (lost bus arbitration, bus error, ..)
  */
-uint8_t twi_writeTo(uint8_t address, uint8_t* data, uint8_t length, uint8_t wait)
+uint8_t twi_writeTo(uint8_t address, uint8_t* data, uint8_t length, uint8_t wait, uint8_t sendStop)
 {
   uint8_t i;
 
@@ -182,6 +203,7 @@ uint8_t twi_writeTo(uint8_t address, uint8_t* data, uint8_t length, uint8_t wait
     continue;
   }
   twi_state = TWI_MTX;
+  twi_sendStop = sendStop;
   // reset error state (0xFF.. no error occured)
   twi_error = 0xFF;
 
@@ -198,8 +220,23 @@ uint8_t twi_writeTo(uint8_t address, uint8_t* data, uint8_t length, uint8_t wait
   twi_slarw = TW_WRITE;
   twi_slarw |= address << 1;
   
-  // send start condition
-  TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTA);
+  // if we're in a repeated start, then we've already sent the START
+  // in the ISR. Don't do it again.
+  //
+  if (true == twi_inRepStart) {
+    // if we're in the repeated start state, then we've already sent the start,
+    // (@@@ we hope), and the TWI statemachine is just waiting for the address byte.
+    // We need to remove ourselves from the repeated start state before we enable interrupts,
+    // since the ISR is ASYNC, and we could get confused if we hit the ISR before cleaning
+    // up. Also, don't enable the START interrupt. There may be one pending from the 
+    // repeated start that we sent outselves, and that would really confuse things.
+    twi_inRepStart = false;			// remember, we're dealing with an ASYNC ISR
+    TWDR = twi_slarw;				
+    TWCR = _BV(TWINT) | _BV(TWEA) | _BV(TWEN) | _BV(TWIE);	// enable INTs, but not START
+  }
+  else
+    // send start condition
+    TWCR = _BV(TWINT) | _BV(TWEA) | _BV(TWEN) | _BV(TWIE) | _BV(TWSTA);	// enable INTs
 
   // wait for write operation to complete
   while(wait && (TWI_MTX == twi_state)){
@@ -343,7 +380,16 @@ SIGNAL(TWI_vect)
         TWDR = twi_masterBuffer[twi_masterBufferIndex++];
         twi_reply(1);
       }else{
-        twi_stop();
+	if (twi_sendStop)
+          twi_stop();
+	else {
+	  twi_inRepStart = true;	// we're gonna send the START
+	  // don't enable the interrupt. We'll generate the start, but we 
+	  // avoid handling the interrupt until we're in the next transaction,
+	  // at the point where we would normally issue the start.
+	  TWCR = _BV(TWINT) | _BV(TWSTA)| _BV(TWEN) ;
+	  twi_state = TWI_READY;
+	}
       }
       break;
     case TW_MT_SLA_NACK:  // address sent, nack received
@@ -374,6 +420,17 @@ SIGNAL(TWI_vect)
     case TW_MR_DATA_NACK: // data received, nack sent
       // put final byte into buffer
       twi_masterBuffer[twi_masterBufferIndex++] = TWDR;
+	if (twi_sendStop)
+          twi_stop();
+	else {
+	  twi_inRepStart = true;	// we're gonna send the START
+	  // don't enable the interrupt. We'll generate the start, but we 
+	  // avoid handling the interrupt until we're in the next transaction,
+	  // at the point where we would normally issue the start.
+	  TWCR = _BV(TWINT) | _BV(TWSTA)| _BV(TWEN) ;
+	  twi_state = TWI_READY;
+	}    
+	break;
     case TW_MR_SLA_NACK: // address sent, nack received
       twi_stop();
       break;
diff --git a/libraries/Wire/utility/twi.h b/libraries/Wire/utility/twi.h
index 831b928..6526593 100755
--- a/libraries/Wire/utility/twi.h
+++ b/libraries/Wire/utility/twi.h
@@ -40,8 +40,8 @@
   
   void twi_init(void);
   void twi_setAddress(uint8_t);
-  uint8_t twi_readFrom(uint8_t, uint8_t*, uint8_t);
-  uint8_t twi_writeTo(uint8_t, uint8_t*, uint8_t, uint8_t);
+  uint8_t twi_readFrom(uint8_t, uint8_t*, uint8_t, uint8_t);
+  uint8_t twi_writeTo(uint8_t, uint8_t*, uint8_t, uint8_t, uint8_t);
   uint8_t twi_transmit(const uint8_t*, uint8_t);
   void twi_attachSlaveRxEvent( void (*)(uint8_t*, int) );
   void twi_attachSlaveTxEvent( void (*)(void) );