Hello, it's my first time posting here.
I need to get a javascript variable into an int variable, to then turn on an LED depending of the pin in the variable. I created a web server on Arduino WiFi Rev2 with the HTML code working, but I don't know how to convert the javascript variable p into an Arduino int. The Arduino code is attached, but you need to put your SSID and password.
This is the HTML code. You have to put the link + "?p=" and then a number between 2, 7 and 12, the positions of the LEDs. The code will then redirect to a page (google.com in this case). I hope you understood my problem.
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<script>
function getUrlVars() {
var vars = {};
var parts = window.location.href.replace(/[?&]+([^=&]+)=([^&]*)/gi, function(m,key,value) {
vars[key] = value;
});
return vars;
}
function getPin(p) {
alert(p);
if(p == 2) {
window.open("www.google.com", "_self");
}
else if(p == 7) {
window.open("www.google.com", "_self");
}
else if(p == 12) {
window.open("www.google.com", "_self");
}
}
</script>
</head>
<body>
<script type="text/javascript">
window.onload = function() {
var p = getUrlVars()["p"];
getPin(p);
}
</script>
</body>
</html>
Java documentation will tell you the number of bytes in that variable. When your Arduino reads that number of bytes, it has the variable. If this was my problem, I would use Serial.print() to look at what was sent and go from there.
I did some testing and figured out I can get the value from a character. Here's the code. Thank you for your response, Paul.
#include <SPI.h>
#include <WiFiNINA.h>
#include "arduino_secrets.h"
char ssid[] = SECRET_SSID; // your network SSID (name)
char pass[] = SECRET_PASS; // your network password (use for WPA, or use as key for WEP)
int keyIndex = 0; // your network key Index number (needed only for WEP)
int status = WL_IDLE_STATUS;
int i;
int pin = 0;
WiFiServer server(80);
void setup() {
//Initialize serial and wait for port to open:
Serial.begin(9600);
while (!Serial) {
; // wait for serial port to connect. Needed for native USB port only
}
pinMode(2, OUTPUT);
digitalWrite(2, LOW);
pinMode(7, OUTPUT);
digitalWrite(7, LOW);
pinMode(12, OUTPUT);
digitalWrite(12, LOW);
// check for the WiFi module:
if (WiFi.status() == WL_NO_MODULE) {
Serial.println("Communication with WiFi module failed!");
// don't continue
while (true);
}
String fv = WiFi.firmwareVersion();
if (fv < WIFI_FIRMWARE_LATEST_VERSION) {
Serial.println("Please upgrade the firmware");
}
// attempt to connect to Wifi network:
while (status != WL_CONNECTED) {
Serial.print("Attempting to connect to SSID: ");
Serial.println(ssid);
// Connect to WPA/WPA2 network
status = WiFi.begin(ssid, pass);
// wait 10 seconds for connection:
delay(10000);
}
server.begin();
//print out the status
printWifiStatus();
}
void loop() {
// listen for incoming clients
WiFiClient 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(c == '?') {
i = 4;
}
if(i == 1) {
pin = int(c);
pin-=48;
}
else if(!i) {
if(c >= 48 && c <= 57) {
pin = pin*10 + int(c) - 48;
}
}
// 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();
client.println("<!DOCTYPE html>");
client.println("<html>");
client.println(" <head>");
client.println(" <meta charset='utf-8'>");
client.println(" <title></title>");
client.println(" <script>");
client.println(" function getUrlVars() {");
client.println(" var vars = {};");
client.println(" var parts = window.location.href.replace(/[?&]+([^=&]+)=([^&]*)/gi, function(m,key,value) {");
client.println(" vars[key] = value;");
client.println(" });");
client.println(" return vars;");
client.println(" }");
client.println(" function getPin(p) {");
client.println(" if(p == 2) {");
client.println(" window.open('https://www.google.com', '_self');");
client.println(" }");
client.println(" else if(p == 7) {");
client.println(" window.open('https://www.google.com', '_self');");
client.println(" }");
client.println(" else if(p == 12) {");
client.println(" window.open('https://www.google.com', '_self');");
client.println(" }");
client.println("");
client.println(" }");
client.println(" </script>");
client.println(" </head>");
client.println(" <body>");
client.println(" <script type='text/javascript'>");
client.println(" window.onload = function() {");
client.println(" var p = getUrlVars()['p'];");
client.println(" getPin(p);");
client.println(" }");
client.println(" </script>");
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;
}
}
i--;
}
// give the web browser time to receive the data
delay(1);
// close the connection:
client.stop();
Serial.println("client disconnected");
Serial.println(pin);
digitalWrite(pin, HIGH);
delay(5000);
digitalWrite(pin, LOW);
pin = 0;
}
}
void printWifiStatus() {
// print the SSID of the network you're attached to:
Serial.print("SSID: ");
Serial.println(WiFi.SSID());
// print your board's IP address:
IPAddress ip = WiFi.localIP();
Serial.print("IP Address: ");
Serial.println(ip);
// print the received signal strength:
long rssi = WiFi.RSSI();
Serial.print("signal strength (RSSI):");
Serial.print(rssi);
Serial.println(" dBm");
}