- Thu Mar 03, 2016 4:36 am
#42295
Hi , I modified the example advancedwebserver.ino to use as an access point and webserver which worked but then I noticed that every so often there is a 3 second delay, usually this occurs within a few requests. It does not happen until at least 1 request has been made.
The delay occurs somewhere inside the server.handleClient() call. I added some print outs to the code as follows
Some sample output from runs
0
0
3077
handleRoot() BEGIN
handleRoot() END
87
0
0
--------------------------
0
0
3066
0
0
Note that the request itself is handled normally (87ms in the first case above ) but the delay occurs randomly during server.handleClient() when there is no request going on.
Anyone got any ideas about this ?
If someone else could try this and report if they get the same result that would be great to see if its just my board or in fact a bug somewhere.
thanks
lynton
The delay occurs somewhere inside the server.handleClient() call. I added some print outs to the code as follows
Code: Select all
#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>
// forward declarations required for 1,6,7 to compile.
void drawGraph();
void printFlush(const char*);
const char *ssid = "TSHIRT";
const char *password = "12345678";
ESP8266WebServer server ( 80 );
const int led = 13;
void handleRoot() {
printFlush("handleRoot() BEGIN");
digitalWrite ( led, 1 );
char temp[400];
int sec = millis() / 1000;
int min = sec / 60;
int hr = min / 60;
snprintf ( temp, 400,
"<html>\
<head>\
<meta http-equiv='refresh' content='5'/>\
<title>ESP8266 Demo</title>\
<style>\
body { background-color: #cccccc; font-family: Arial, Helvetica, Sans-Serif; Color: #000088; }\
</style>\
</head>\
<body>\
<h1>Hello from ESP8266!</h1>\
<p>Uptime: %02d:%02d:%02d</p>\
<img src=\"/test.svg\" />\
</body>\
</html>",
hr, min % 60, sec % 60
);
server.send ( 200, "text/html", temp );
digitalWrite ( led, 0 );
printFlush("handleRoot() END");
}
void handleNotFound() {
printFlush("handleNotFound() BEGIN");
digitalWrite ( led, 1 );
String message = "File Not Found\n\n";
message += "URI: ";
message += server.uri();
message += "\nMethod: ";
message += ( server.method() == HTTP_GET ) ? "GET" : "POST";
message += "\nArguments: ";
message += server.args();
message += "\n";
for ( uint8_t i = 0; i < server.args(); i++ ) {
message += " " + server.argName ( i ) + ": " + server.arg ( i ) + "\n";
}
server.send ( 404, "text/plain", message );
digitalWrite ( led, 0 );
printFlush("handleNotFound() END");
}
void setup ( void ) {
pinMode ( led, OUTPUT );
digitalWrite ( led, 0 );
Serial.begin ( 115200 );
WiFi.softAP(ssid, password);
IPAddress myIP = WiFi.softAPIP();
Serial.print("AP IP address: ");
Serial.println(myIP);
WiFi.begin ( ssid, password );
Serial.println ( "" );
if ( MDNS.begin ( "esp8266" ) ) {
Serial.println ( "MDNS responder started" );
}
server.on ( "/", handleRoot );
server.on ( "/test.svg", drawGraph );
server.on ( "/inline", []() {
server.send ( 200, "text/plain", "this works as well" );
} );
server.onNotFound ( handleNotFound );
server.begin();
Serial.println ( "HTTP server started" );
}
void printFlush(const char* str) {
Serial.println(str);
Serial.flush();
}
void loop ( void ) {
static long countdown = 0l;
unsigned long before = millis();
server.handleClient();
unsigned long after = millis();
printFlush(String(after - before).c_str());
if (after - before > 100) {
// start countdown
countdown = 30;
}
if (countdown > 0) {
countdown--;
if (countdown == 1) {
delay(100000);// stop so we can capture the surrounding output.
}
}
}
void drawGraph() {
printFlush("drawGraph() BEGIN");
String out = "";
char temp[100];
out += "<svg xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" width=\"400\" height=\"150\">\n";
out += "<rect width=\"400\" height=\"150\" fill=\"rgb(250, 230, 210)\" stroke-width=\"1\" stroke=\"rgb(0, 0, 0)\" />\n";
out += "<g stroke=\"black\">\n";
int y = rand() % 130;
for (int x = 10; x < 390; x += 10) {
int y2 = rand() % 130;
sprintf(temp, "<line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke-width=\"1\" />\n", x, 140 - y, x + 10, 140 - y2);
out += temp;
y = y2;
}
out += "</g>\n</svg>\n";
server.send ( 200, "image/svg+xml", out);
printFlush("drawGraph() END");
}
Some sample output from runs
0
0
3077
handleRoot() BEGIN
handleRoot() END
87
0
0
--------------------------
0
0
3066
0
0
Note that the request itself is handled normally (87ms in the first case above ) but the delay occurs randomly during server.handleClient() when there is no request going on.
Anyone got any ideas about this ?
If someone else could try this and report if they get the same result that would be great to see if its just my board or in fact a bug somewhere.
thanks
lynton
