Problems with the Uno R4 WiFi

Projects Networking, Protocols, and Devices
1

Introduction

I am testing out a sketch that was originally made for Uno WiFi Rev 2. The expected output is a web page displaying:

testing
asdfghjk
[a random number]

The original sketch (that works on the Uno WiFi Rev. 2)

#include <SPI.h>
#include <WiFiNINA.h>

char ssid[] = [REDACTED];       //  your network SSID (name)
char pass[] = [REDACTED];  // your network password
int status = WL_IDLE_STATUS;

IPAddress ip([REDACTED]);
IPAddress dns([REDACTED]);
IPAddress gateway([REDACTED]);
IPAddress subnet([REDACTED]);

WiFiServer server(80);
void setup() {
  Serial.begin(9600);
  Serial.println("Attempting to connect to WPA network...");
  Serial.print("SSID: ");
  Serial.println(ssid);
  WiFi.config(ip, dns, gateway, subnet);
  status = WiFi.begin(ssid, pass);
  if (status != WL_CONNECTED) {
    Serial.println("Couldn't get a WiFi connection");
    while (true)
      ;
  } else {
    server.begin();
    Serial.print("Connected to WiFi. My address:");
    Serial.println(WiFi.localIP());
  }
}

void loop() {
  // listen for incoming clients
  WiFiClient client = server.available();
  if (client) {
    Serial.println("client connected");
    // 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
        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("<html>");
          client.println("<body>");
          client.println("<p>testing</p>");
          client.println("<p>asdfghjk</p>");
          client.print("<p>");
          client.print(random());
          client.print("</p>");
          client.println("</body>");
          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");
  }
}

First problem

I modified the sketch to work with the Uno R4 WiFi, and tried it on both the offline IDE and the online Web Editor. random() does not seem to be recognized by either.

My sketch, modified for the R4 WiFi

#include "WiFiS3.h"

char ssid[] = [REDACTED];       //  your network SSID (name)
char pass[] = [REDACTED];  // your network password
int status = WL_IDLE_STATUS;

IPAddress ip([REDACTED]);
IPAddress dns([REDACTED]);
IPAddress gateway([REDACTED]);
IPAddress subnet([REDACTED]);

WiFiServer server(80);
void setup() {
  Serial.begin(9600);
  Serial.println("Attempting to connect to WPA network...");
  Serial.print("SSID: ");
  Serial.println(ssid);
  WiFi.config(ip, dns, gateway, subnet);
  status = WiFi.begin(ssid, pass);
  if (status != WL_CONNECTED) {
    Serial.println("Couldn't get a WiFi connection");
    while (true)
      ;
  } else {
    server.begin();
    Serial.print("Connected to WiFi. My address:");
    Serial.println(WiFi.localIP());
  }
}

void loop() {
  // listen for incoming clients
  WiFiClient client = server.available();
  if (client) {
    Serial.println("client connected");
    // 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
        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("<html>");
          client.println("<body>");
          client.println("<p>testing</p>");
          client.println("<p>asdfghjk</p>");
          client.print("<p>");
          client.print(random());
          client.print("</p>");
          client.println("</body>");
          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");
  }
}

Error mesage displayed on the serial monitor, using the Arduino (Web) Editor

/usr/local/bin/arduino-cli compile --fqbn arduino:renesas_uno:unor4wifi --build-cache-path /tmp --output-dir /tmp/3208599453/build --build-path /tmp/arduino-build-C75150C49F1B578B8AA60CC0E97B5CB6 /tmp/3208599453/sketch_apr7a

/tmp/3208599453/sketch_apr7a/sketch_apr7a.ino: In function 'void loop()':

/tmp/3208599453/sketch_apr7a/sketch_apr7a.ino:57:31: error: no matching function for call to 'random()'

client.print(random());

^

In file included from /home/builder/.arduino15/packages/arduino/hardware/renesas_uno/1.0.1/cores/arduino/api/Interrupts.h:8:0,

from /home/builder/.arduino15/packages/arduino/hardware/renesas_uno/1.0.1/cores/arduino/api/ArduinoAPI.h:29,

from /home/builder/.arduino15/packages/arduino/hardware/renesas_uno/1.0.1/cores/arduino/Arduino.h:4,

from /tmp/arduino-build-C75150C49F1B578B8AA60CC0E97B5CB6/sketch/sketch_apr7a.ino.cpp:1:

/home/builder/.arduino15/packages/arduino/hardware/renesas_uno/1.0.1/cores/arduino/api/Common.h:166:6: note: candidate: long int random(long int)

long random(long);

^~~~~~

/home/builder/.arduino15/packages/arduino/hardware/renesas_uno/1.0.1/cores/arduino/api/Common.h:166:6: note: candidate expects 1 argument, 0 provided

/home/builder/.arduino15/packages/arduino/hardware/renesas_uno/1.0.1/cores/arduino/api/Common.h:167:6: note: candidate: long int random(long int, long int)

long random(long, long);

^~~~~~

/home/builder/.arduino15/packages/arduino/hardware/renesas_uno/1.0.1/cores/arduino/api/Common.h:167:6: note: candidate expects 2 arguments, 0 provided

Error during build: exit status 1

Error mesage displayed on the serial monitor, using the Arduino (offline) IDE

C:\Users\tcdd\Documents\Arduino\web_server_config_R4\web_server_config_R4.ino: In function 'void loop()':
C:\Users\tcdd\Documents\Arduino\web_server_config_R4\web_server_config_R4.ino:57:31: error: no matching function for call to 'random()'
           client.print(random());
                               ^
In file included from C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\cores\arduino/api/Interrupts.h:8:0,
                 from C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\cores\arduino/api/ArduinoAPI.h:29,
                 from C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\cores\arduino/Arduino.h:4,
                 from C:\Users\tcdd\AppData\Local\Temp\arduino\sketches\448DF2B19A5584EBAEC7593B04703CCD\sketch\web_server_config_R4.ino.cpp:1:
C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\cores\arduino/api/Common.h:166:6: note: candidate: long int random(long int)
 long random(long);
      ^~~~~~
C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\cores\arduino/api/Common.h:166:6: note:   candidate expects 1 argument, 0 provided
C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\cores\arduino/api/Common.h:167:6: note: candidate: long int random(long int, long int)
 long random(long, long);
      ^~~~~~
C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\cores\arduino/api/Common.h:167:6: note:   candidate expects 2 arguments, 0 provided

exit status 1

Compilation error: no matching function for call to 'random()'

Second problem

I modified the sketch, disabling random(). It works on the Web Editor, but not the (offline) IDE; with the latter, the Arduino R4 WiFi won't connect to the network, and no error messages are displayed unless I enable compiler warnings.

Version* of R4 sketch with random() disabled

*Works on the Web Editor, but not the offline IDE.

#include "WiFiS3.h"

char ssid[] = [REDACTED];       //  your network SSID (name)
char pass[] = [REDACTED];  // your network password
int status = WL_IDLE_STATUS;

IPAddress ip([REDACTED]);
IPAddress dns([REDACTED]);
IPAddress gateway([REDACTED]);
IPAddress subnet([REDACTED]);

WiFiServer server(80);
void setup() {
  Serial.begin(9600);
  Serial.println("Attempting to connect to WPA network...");
  Serial.print("SSID: ");
  Serial.println(ssid);
  WiFi.config(ip, dns, gateway, subnet);
  status = WiFi.begin(ssid, pass);
  if (status != WL_CONNECTED) {
    Serial.println("Couldn't get a WiFi connection");
    while (true)
      ;
  } else {
    server.begin();
    Serial.print("Connected to WiFi. My address:");
    Serial.println(WiFi.localIP());
  }
}

void loop() {
  // listen for incoming clients
  WiFiClient client = server.available();
  if (client) {
    Serial.println("client connected");
    // 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
        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("<html>");
          client.println("<body>");
          client.println("<p>testing</p>");
          client.println("<p>asdfghjk</p>");
          //client.print("<p>");
          //client.print(random());
          //client.print("</p>");
          client.println("</body>");
          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");
  }
}

Compiler warnings

In file included from C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\libraries\WiFiS3\src/WiFiS3.h:26:0,
                 from C:\Users\tcdd\AppData\Local\Temp\.arduinoIDE-unsaved2023625-15952-1owok8z.9zk1\sketch_jul25a\sketch_jul25a.ino:1:
C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\libraries\WiFiS3\src/WiFiUdp.h:33:0: warning: "RX_BUFFER_DIM" redefined
 #define RX_BUFFER_DIM 1461
 
In file included from C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\libraries\WiFiS3\src/WiFiS3.h:24:0,
                 from C:\Users\tcdd\AppData\Local\Temp\.arduinoIDE-unsaved2023625-15952-1owok8z.9zk1\sketch_jul25a\sketch_jul25a.ino:1:
C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\libraries\WiFiS3\src/WiFiClient.h:33:0: note: this is the location of the previous definition
 #define RX_BUFFER_DIM 1024
 
In file included from C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\libraries\WiFiS3\src/WiFi.h:7:0,
                 from C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\libraries\WiFiS3\src/WiFiS3.h:23,
                 from C:\Users\tcdd\AppData\Local\Temp\.arduinoIDE-unsaved2023625-15952-1owok8z.9zk1\sketch_jul25a\sketch_jul25a.ino:1:
C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\libraries\WiFiS3\src/WiFiCommands.h:17:3: warning: 'file_op' defined but not used [-Wunused-variable]
 } file_op;
   ^~~~~~~
C:\Users\tcdd\AppData\Local\Arduino15\packages\arduino\hardware\renesas_uno\1.0.2\libraries\WiFiS3\src/WiFiCommands.h:10:3: warning: 'ip_type' defined but not used [-Wunused-variable]
 } ip_type;
   ^~~~~~~
2 
client.print(random());

The random() function needs at least one parameter

1 Like
4

Giving the function the parameters "0, 1023" (for example) solves the first problem. (But the second problem still applies.)

Why doesn't the Uno WiFi Rev 2 require parameters for the random() function, but the Uno R4 WiFi does?

5

What range of values does the Uno WiFi Rev 2 return when you use random() with no parameters ?

6

Here's what I get when I when I run this* sketch for about a minute:
RANDOM.TXT (45.1 KB)

*The sketch:

#include <SPI.h>
#include <SD.h>

int x = 0;

File theFile;

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
  SD.begin(4);
}

void loop() {
  for (x = 0; x <= 60000; x++) {
    theFile = SD.open("random.txt", FILE_WRITE);

    theFile.println(random());

    theFile.close();

    delay(1);
  }

/*
I didn't get the following part right; the LED was supposed to turn on after a minute:
*/

  if (x >= 60000) {
    digitalWrite(LED_BUILTIN, HIGH);
    while (1) {
      ;
    }
  }
}
7

More importantly, what range of values do you want from the random() function ?

8

In this particular instance, it doesn't really matter, as long as I'm getting a different number every time the page refreshes. The purpose of the sketch is for practicing and testing the code for the WiFi functionality of the Arduino.

9

Randomness isn't good for this kind of testing. It could send a 666, you receive a 844, and you would never know.

10

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