All examples to check hardware & link to help users troubleshoot

Author: PaulStoffregen

examples/AdvancedChatServer/AdvancedChatServer.ino

@@ -50,14 +50,26 @@ void setup() {
 
   // initialize the Ethernet device
   Ethernet.begin(mac, ip, myDns, gateway, subnet);
-  // start listening for clients
-  server.begin();
+
   // Open serial communications and wait for port to open:
   Serial.begin(9600);
   while (!Serial) {
     ; // wait for serial port to connect. Needed for native USB port only
   }
 
+  // Check for Ethernet hardware present
+  if (Ethernet.hardwareStatus() == EthernetNoHardware) {
+    Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
+    while (true) {
+      delay(1); // do nothing, no point running without Ethernet hardware
+    }
+  }
+  if (Ethernet.linkStatus() == LinkOFF) {
+    Serial.println("Ethernet cable is not connected.");
+  }
+
+  // start listening for clients
+  server.begin();
 
   Serial.print("Chat server address:");
   Serial.println(Ethernet.localIP());

examples/BarometricPressureWebServer/BarometricPressureWebServer.ino

@@ -69,16 +69,33 @@ void setup() {
   // start the SPI library:
   SPI.begin();
 
-  // start the Ethernet connection and the server:
+  // start the Ethernet connection
   Ethernet.begin(mac, ip);
+
+  // Open serial communications and wait for port to open:
+  Serial.begin(9600);
+  while (!Serial) {
+    ; // wait for serial port to connect. Needed for native USB port only
+  }
+
+  // Check for Ethernet hardware present
+  if (Ethernet.hardwareStatus() == EthernetNoHardware) {
+    Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
+    while (true) {
+      delay(1); // do nothing, no point running without Ethernet hardware
+    }
+  }
+  if (Ethernet.linkStatus() == LinkOFF) {
+    Serial.println("Ethernet cable is not connected.");
+  }
+
+  // start listening for clients
   server.begin();
 
   // initalize the data ready and chip select pins:
   pinMode(dataReadyPin, INPUT);
   pinMode(chipSelectPin, OUTPUT);
 
-  Serial.begin(9600);
-
   //Configure SCP1000 for low noise configuration:
   writeRegister(0x02, 0x2D);
   writeRegister(0x01, 0x03);

examples/ChatServer/ChatServer.ino

@@ -45,14 +45,26 @@ void setup() {
 
   // initialize the ethernet device
   Ethernet.begin(mac, ip, myDns, gateway, subnet);
-  // start listening for clients
-  server.begin();
+
   // Open serial communications and wait for port to open:
   Serial.begin(9600);
    while (!Serial) {
     ; // wait for serial port to connect. Needed for native USB port only
   }
 
+  // Check for Ethernet hardware present
+  if (Ethernet.hardwareStatus() == EthernetNoHardware) {
+    Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
+    while (true) {
+      delay(1); // do nothing, no point running without Ethernet hardware
+    }
+  }
+  if (Ethernet.linkStatus() == LinkOFF) {
+    Serial.println("Ethernet cable is not connected.");
+  }
+
+  // start listening for clients
+  server.begin();
 
   Serial.print("Chat server address:");
   Serial.println(Ethernet.localIP());

examples/DhcpAddressPrinter/DhcpAddressPrinter.ino

@@ -36,7 +36,6 @@ void setup() {
 
   // Open serial communications and wait for port to open:
   Serial.begin(9600);
-  // this check is only needed on the Leonardo:
   while (!Serial) {
     ; // wait for serial port to connect. Needed for native USB port only
   }
@@ -45,12 +44,19 @@ void setup() {
   Serial.println("Initialize Ethernet with DHCP:");
   if (Ethernet.begin(mac) == 0) {
     Serial.println("Failed to configure Ethernet using DHCP");
+    if (Ethernet.hardwareStatus() == EthernetNoHardware) {
+      Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
+    } else if (Ethernet.linkStatus() == LinkOFF) {
+      Serial.println("Ethernet cable is not connected.");
+    }
     // no point in carrying on, so do nothing forevermore:
-    for (;;)
-      ;
+    while (true) {
+      delay(1);
+    }
   }
   // print your local IP address:
-  printIPAddress();
+  Serial.print("My IP address: ");
+  Serial.println(Ethernet.localIP());
 }
 
 void loop() {
@@ -64,7 +70,8 @@ void loop() {
       //renewed success
       Serial.println("Renewed success");
       //print your local IP address:
-      printIPAddress();
+      Serial.print("My IP address: ");
+      Serial.println(Ethernet.localIP());
       break;
 
     case 3:
@@ -76,7 +83,8 @@ void loop() {
       //rebind success
       Serial.println("Rebind success");
       //print your local IP address:
-      printIPAddress();
+      Serial.print("My IP address: ");
+      Serial.println(Ethernet.localIP());
       break;
 
     default:
@@ -85,7 +93,3 @@ void loop() {
   }
 }
 
-void printIPAddress() {
-  Serial.print("My IP address: ");
-  Serial.println(Ethernet.localIP());
-}

examples/DhcpChatServer/DhcpChatServer.ino

@@ -49,16 +49,24 @@ void setup() {
 
   // Open serial communications and wait for port to open:
   Serial.begin(9600);
-  // this check is only needed on the Leonardo:
-   while (!Serial) {
+  while (!Serial) {
     ; // wait for serial port to connect. Needed for native USB port only
   }
 
-
   // start the Ethernet connection:
   Serial.println("Trying to get an IP address using DHCP");
   if (Ethernet.begin(mac) == 0) {
     Serial.println("Failed to configure Ethernet using DHCP");
+    // Check for Ethernet hardware present
+    if (Ethernet.hardwareStatus() == EthernetNoHardware) {
+      Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
+      while (true) {
+        delay(1); // do nothing, no point running without Ethernet hardware
+      }
+    }
+    if (Ethernet.linkStatus() == LinkOFF) {
+      Serial.println("Ethernet cable is not connected.");
+    }
     // initialize the Ethernet device not using DHCP:
     Ethernet.begin(mac, ip, myDns, gateway, subnet);
   }

examples/TelnetClient/TelnetClient.ino

@@ -47,12 +47,24 @@ void setup() {
 
   // start the Ethernet connection:
   Ethernet.begin(mac, ip);
+
   // Open serial communications and wait for port to open:
   Serial.begin(9600);
   while (!Serial) {
     ; // wait for serial port to connect. Needed for native USB port only
   }
 
+  // Check for Ethernet hardware present
+  if (Ethernet.hardwareStatus() == EthernetNoHardware) {
+    Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
+    while (true) {
+      delay(1); // do nothing, no point running without Ethernet hardware
+    }
+  }
+  while (Ethernet.linkStatus() == LinkOFF) {
+    Serial.println("Ethernet cable is not connected.");
+    delay(500);
+  }
 
   // give the Ethernet shield a second to initialize:
   delay(1000);
@@ -90,7 +102,9 @@ void loop() {
     Serial.println("disconnecting.");
     client.stop();
     // do nothing:
-    while (true);
+    while (true) {
+      delay(1);
+    }
   }
 }
 

examples/UDPSendReceiveString/UDPSendReceiveString.ino

@@ -13,10 +13,8 @@
  */
 
 
-#include <SPI.h>         // needed for Arduino versions later than 0018
 #include <Ethernet.h>
-#include <EthernetUdp.h>         // UDP library from: bjoern@cs.stanford.edu 12/30/2008
-
+#include <EthernetUdp.h>
 
 // Enter a MAC address and IP address for your controller below.
 // The IP address will be dependent on your local network:
@@ -43,11 +41,28 @@ void setup() {
   //Ethernet.init(15);  // ESP8266 with Adafruit Featherwing Ethernet
   //Ethernet.init(33);  // ESP32 with Adafruit Featherwing Ethernet
 
-  // start the Ethernet and UDP:
+  // start the Ethernet
   Ethernet.begin(mac, ip);
-  Udp.begin(localPort);
 
+  // Open serial communications and wait for port to open:
   Serial.begin(9600);
+  while (!Serial) {
+    ; // wait for serial port to connect. Needed for native USB port only
+  }
+
+  // Check for Ethernet hardware present
+  if (Ethernet.hardwareStatus() == EthernetNoHardware) {
+    Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
+    while (true) {
+      delay(1); // do nothing, no point running without Ethernet hardware
+    }
+  }
+  if (Ethernet.linkStatus() == LinkOFF) {
+    Serial.println("Ethernet cable is not connected.");
+  }
+
+  // start UDP
+  Udp.begin(localPort);
 }
 
 void loop() {

examples/UdpNtpClient/UdpNtpClient.ino

@@ -54,13 +54,19 @@ void setup() {
     ; // wait for serial port to connect. Needed for native USB port only
   }
 
-
   // start Ethernet and UDP
   if (Ethernet.begin(mac) == 0) {
     Serial.println("Failed to configure Ethernet using DHCP");
+    // Check for Ethernet hardware present
+    if (Ethernet.hardwareStatus() == EthernetNoHardware) {
+      Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
+    } else if (Ethernet.linkStatus() == LinkOFF) {
+      Serial.println("Ethernet cable is not connected.");
+    }
     // no point in carrying on, so do nothing forevermore:
-    for (;;)
-      ;
+    while (true) {
+      delay(1);
+    }
   }
   Udp.begin(localPort);
 }

examples/WebClient/WebClient.ino

@@ -20,6 +20,7 @@
 // Enter a MAC address for your controller below.
 // Newer Ethernet shields have a MAC address printed on a sticker on the shield
 byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
+
 // 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(74,125,232,128);  // numeric IP for Google (no DNS)
@@ -58,7 +59,16 @@ void setup() {
   Serial.println("Initialize Ethernet with DHCP:");
   if (Ethernet.begin(mac) == 0) {
     Serial.println("Failed to configure Ethernet using DHCP");
-    // no point in carrying on, so do nothing forevermore:
+    // Check for Ethernet hardware present
+    if (Ethernet.hardwareStatus() == EthernetNoHardware) {
+      Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
+      while (true) {
+        delay(1); // do nothing, no point running without Ethernet hardware
+      }
+    }
+    if (Ethernet.linkStatus() == LinkOFF) {
+      Serial.println("Ethernet cable is not connected.");
+    }
     // try to congifure using IP address instead of DHCP:
     Ethernet.begin(mac, ip, myDns);
   } else {
@@ -119,7 +129,9 @@ void loop() {
     Serial.println();
 
     // do nothing forevermore:
-    while (true);
+    while (true) {
+      delay(1);
+    }
   }
 }
 

examples/WebClientRepeating/WebClientRepeating.ino

@@ -62,7 +62,16 @@ void setup() {
   Serial.println("Initialize Ethernet with DHCP:");
   if (Ethernet.begin(mac) == 0) {
     Serial.println("Failed to configure Ethernet using DHCP");
-    // no point in carrying on, so do nothing forevermore:
+    // Check for Ethernet hardware present
+    if (Ethernet.hardwareStatus() == EthernetNoHardware) {
+      Serial.println("Ethernet shield was not found.  Sorry, can't run without hardware. :(");
+      while (true) {
+        delay(1); // do nothing, no point running without Ethernet hardware
+      }
+    }
+    if (Ethernet.linkStatus() == LinkOFF) {
+      Serial.println("Ethernet cable is not connected.");
+    }
     // try to congifure using IP address instead of DHCP:
     Ethernet.begin(mac, ip, myDns);
     Serial.print("My IP address: ");