Hi All,
I’m hoping the forum can help me troubleshoot an issue with a DFRobot Ethernet Shield (DFR0850). I’m having an issue with getting the board to connect to the network and obtain an IP by either DHPC or by setting a static IP. The board is connected to an Arduino UNO with an Atmega 328P. I have tried a number of test sketches and online tutorials to troubleshoot the issue without success.
Here are two example sketches I am running to test the function of the board:
First sketch
/*
Link Status
This sketch prints the Ethernet link status. When the
Ethernet cable is connected the link status should go to "ON".
NOTE: Only WIZnet W5200 and W5500 are capable of reporting
the link status. W5100 will report "Unknown".
Hardware:
- Ethernet shield or equivalent board/shield with WIZnet W5200/W5500
Written by Cristian Maglie
This example is public domain.
*/
#include <SPI.h>
#include <Ethernet.h>
void setup() {
// You can use Ethernet.init(pin) to configure the CS pin
Ethernet.init(10); // Most Arduino shields
//Ethernet.init(5); // MKR ETH Shield
//Ethernet.init(0); // Teensy 2.0
//Ethernet.init(20); // Teensy++ 2.0
//Ethernet.init(15); // ESP8266 with Adafruit FeatherWing Ethernet
//Ethernet.init(33); // ESP32 with Adafruit FeatherWing Ethernet
Serial.begin(9600);
// disable SD SPI as this can interfere with the W5500
pinMode(4,OUTPUT);
digitalWrite(4,HIGH);
}
void loop() {
auto link = Ethernet.linkStatus();
Serial.print("Link status: ");
switch (link) {
case Unknown:
Serial.println("Unknown");
break;
case LinkON:
Serial.println("ON");
break;
case LinkOFF:
Serial.println("OFF");
break;
}
delay(1000);
}
The output on the serial port from this sketch is:
"Link status: Unknown” whether the ethernet cable is plugged in or not (I have tried multiple ethernet cables).
The expected output for a working board would either be:
"Link status: ON” OR
"Link status: OFF”
Second sketch:
/*
Web Server
A simple web server that shows the value of the analog input pins.
using an Arduino WIZnet Ethernet shield.
Circuit:
* Ethernet shield attached to pins 10, 11, 12, 13
* Analog inputs attached to pins A0 through A5 (optional)
created 18 Dec 2009
by David A. Mellis
modified 9 Apr 2012
by Tom Igoe
modified 02 Sept 2015
by Arturo Guadalupi
*/
#include <SPI.h>
#include <Ethernet.h>
// 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
};
IPAddress ip(192, 168, 1, 177);
// Initialize the Ethernet server library
// with the IP address and port you want to use
// (port 80 is default for HTTP):
EthernetServer server(80);
void setup() {
// You can use Ethernet.init(pin) to configure the CS pin
Ethernet.init(10); // Most Arduino shields
//Ethernet.init(5); // MKR ETH Shield
//Ethernet.init(0); // Teensy 2.0
//Ethernet.init(20); // Teensy++ 2.0
//Ethernet.init(15); // ESP8266 with Adafruit FeatherWing Ethernet
//Ethernet.init(33); // ESP32 with Adafruit FeatherWing Ethernet
// 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
}
Serial.println("Ethernet WebServer Example");
// start the Ethernet connection and the server:
Ethernet.begin(mac, ip);
// 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 the server
server.begin();
Serial.print("server is at ");
Serial.println(Ethernet.localIP());
}
void loop() {
// listen for incoming clients
EthernetClient client = server.available();
if (client) {
Serial.println("new client");
// an HTTP request ends with a blank line
bool 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
if (c == '\n' && currentLineIsBlank) {
// send a standard HTTP response header
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: text/html");
client.println("Connection: close"); // the connection will be closed after completion of the response
client.println("Refresh: 5"); // refresh the page automatically every 5 sec
client.println();
client.println("<!DOCTYPE HTML>");
client.println("<html>");
// 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(sensorReading);
client.println("<br />");
}
client.println("</html>");
break;
}
if (c == '\n') {
// you're starting a new line
currentLineIsBlank = true;
} else if (c != '\r') {
// you've gotten a character on the current line
currentLineIsBlank = false;
}
}
}
// give the web browser time to receive the data
delay(1);
// close the connection:
client.stop();
Serial.println("client disconnected");
}
}
This sketch also can’t connect to the network. The output on the serial port is:
Ethernet WebServer Example
Ethernet shield was not found. Sorry, can’t run without hardware 
Other troubleshooting steps I have tried are:
- Setting pin 4 as an output and setting it HIGH to disable the SD card SPI which can interfere with the SPI for the W5500.
- Using pin 11 to reset the W5500 board during the setup() routine
- Using a different router and network
- Checking the board for solder bridges (non found)
- Using the Ethernet2 library instead of Ethernet
Any help would be greatly appreciated!
