Greetings and Merry Christmas,
I have a problem that I am hoping some fine Gentleman/Lady could help me with. I have recently started dabbling in the Internet Of Things, so I wrote a small bit of code, that I found on a very helpful online tutorial, that reads a pot and operates a servo. The code seems to work fine in the start then locks up after a bit, it also doesn’t seem to load on mobile web browsers. Would you be so kind as to have a look and give me advice on where it is going wrong.
P.S. If anyone could explain to me how I would be able to control the servo position with a slider that would also be appreciated.
#include <Servo.h>
#include <SPI.h>
#include <Ethernet.h>
#include <SD.h>
#define REQ_BUF_SZ 60
// MAC address from Ethernet shield sticker under board
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(10, 0, 0, 20); // IP address, may need to change depending on network
EthernetServer server(80); // create a server at port 80
Servo Valve1;
File webFile;
char HTTP_req[REQ_BUF_SZ] = {0};
char req_index = 0;
void setup()
{
//disable Ethernet chip
pinMode(10, OUTPUT);
digitalWrite(10, HIGH);
Serial.begin(9600); // for debugging
Valve1.attach(9);
// initialize SD card
Serial.println("Initializing SD card...");
if (!SD.begin(4)) {
Serial.println("ERROR - SD card initialization failed!");
return; // init failed
}
Serial.println("SUCCESS - SD card initialized.");
// check for index.htm file
if (!SD.exists("index.htm")) {
Serial.println("ERROR - Can't find index.htm file!");
return; // can't find index file
}
Serial.println("SUCCESS - Found index.htm file.");
Ethernet.begin(mac, ip); // initialize Ethernet device
server.begin(); // start to listen for clients
}
void loop()
{
EthernetClient client = server.available(); // try to get client
if (client) { // got client?
boolean currentLineIsBlank = true;
while (client.connected()) {
if (client.available()) { // client data available to read
char c = client.read(); // read 1 byte (character) from client
// limit the size of the stored received HTTP request
// buffer first part of HTTP request in HTTP_req array (string)
// leave last element in array as 0 to null terminate string (REQ_BUF_SZ - 1)
if (req_index < (REQ_BUF_SZ - 1)) {
HTTP_req[req_index] = c; // save HTTP request character
req_index++;
}
// last line of client request is blank and ends with \n
// respond to client only after last line received
if (c == '\n' && currentLineIsBlank) {
// send a standard http response header
client.println("HTTP/1.1 200 OK");
// remainder of header follows below, depending on if
// web page or XML page is requested
// Ajax request - send XML file
if (StrContains(HTTP_req, "ajax_inputs")) {
// send rest of HTTP header
client.println("Content-Type: text/xml");
client.println("Connection: keep-alive");
client.println();
Valve();
// send XML file containing input states
XML_response(client);
}
else { // web page request
// send rest of HTTP header
client.println("Content-Type: text/html");
client.println("Connection: keep-alive");
client.println();
// send web page
webFile = SD.open("index.htm"); // open web page file
if (webFile) {
while(webFile.available()) {
client.write(webFile.read()); // send web page to client
}
webFile.close();
}
}
// display received HTTP request on serial port
Serial.print(HTTP_req);
// reset buffer index and all buffer elements to 0
req_index = 0;
StrClear(HTTP_req, REQ_BUF_SZ);
break;
}
// every line of text received from the client ends with \r\n
if (c == '\n') {
// last character on line of received text
// starting new line with next character read
currentLineIsBlank = true;
}
else if (c != '\r') {
// a text character was received from client
currentLineIsBlank = false;
}
} // end if (client.available())
} // end while (client.connected())
delay(1); // give the web browser time to receive the data
client.stop(); // close the connection
} // end if (client)
}
void Valve()
{
if (StrContains(HTTP_req, "Valve=2"))
{
Valve1.write(0);
}
else if (StrContains(HTTP_req, "Valve=1"))
{
Valve1.write(80);
}
else if (StrContains(HTTP_req, "Valve=0"))
{
Valve1.write(160);
}
}
void XML_response(EthernetClient cl)
{
int analog_val;
cl.print("<?xml version = \"1.0\" ?>");
cl.print("<inputs>");
analog_val = analogRead(A5);
cl.print("<sw_an_data>'");
cl.print(analog_val);
cl.println("</sw_an_data>");
}
// searches for the string sfind in the string str
// returns 1 if string found
// returns 0 if string not found
char StrContains(char *str, char *sfind)
{
char found = 0;
char index = 0;
char len;
len = strlen(str);
if (strlen(sfind) > len) {
return 0;
}
while (index < len) {
if (str[index] == sfind[found]) {
found++;
if (strlen(sfind) == found) {
return 1;
}
}
else {
found = 0;
}
index++;
}
return 0;
}
void StrClear(char *str, char length)
{
for (int i = 0; i < length; i++) {
str[i] = 0;
}
}
<!DOCTYPE html>
<html>
<head>
<title>Servo Control and Sensor Data</title>
<script>
strValve = "";
var Flow = 0;
function GetArduinoIO()
{
nocache = "&nocache=" + Math.random() * 1000000;
var request = new XMLHttpRequest();
request.onreadystatechange = function () {
if (this.readyState == 4) {
if (this.status == 200) {
if (this.responseXML != null) {
document.getElementById("sw_an_data").innerHTML = this.responseText;
}
}
}
}
request.open("GET", "ajax_inputs"+ strValve + nocache, true);
request.send(null);
setTimeout("GetArduinoIO()", 1000);
}
function SetStateOpen()
{
strValve = "&Valve=2"
}
function SetStatePartial()
{
strValve = "&Valve=1"
}
function SetStateClosed()
{
strValve = "&Valve=0"
}
</script>
</head>
<body onload="GetArduinoIO()">
<h1>Flow and Valve control</h1>
<div id="sw_an_data">
</div>
<h2>Control</h2>
<button id="Open" onclick="SetStateOpen()">Open Valve</button>
<button id="Partial" onclick="SetStatePartial()">Partially Open Valve</button>
<button id="Close" onclick="SetStateClosed()">Close Valve</button>
</body>
</html>