ESP8266WebServer.h don't refresh json data stream

Hi all,

I’m trying to show live data through index.html served by ESP8266WebServer.h

<!DOCTYPE html>
<svg width="960" height="673" stroke="#fff" stroke-width="0.5"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://d3js.org/d3-hsv.v0.1.min.js"></script>
<script src="https://d3js.org/d3-contour.v1.min.js"></script>
<script>

var svg = d3.select("svg"),
    width = +svg.attr("width"),
    height = +svg.attr("height");

var i0 = d3.interpolateHsvLong(d3.hsv(120, 1, 0.65), d3.hsv(60, 1, 0.90)),
    i1 = d3.interpolateHsvLong(d3.hsv(60, 1, 0.90), d3.hsv(0, 0, 0.95)),
    interpolateTerrain = function(t) { return t < 0.5 ? i0(t * 2) : i1((t - 0.5) * 2); },
    color = d3.scaleSequential(interpolateTerrain).domain([90, 190]);

d3.json("volcano.json", function(error, volcano) {
  if (error) throw error;

  svg.selectAll("path")
    .data(d3.contours()
        .size([volcano.width, volcano.height])
        .thresholds(d3.range(90, 195, 5))
      (volcano.values))
    .enter().append("path")
      .attr("d", d3.geoPath(d3.geoIdentity().scale(width / volcano.width)))
      .attr("fill", function(d) { return color(d.value); });
});

</script>

used in Contour Plot - bl.ocks.org, who needs json.

But the code does not refresh client side continously:

#include <ArduinoJson.h>
#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <FS.h>

const char* ssid = "yourSSID";
const char* password = "yourPASS";
const char* htmlfile = "/index.html";

ESP8266WebServer server(80);


// several const definitions on attached. 

void setup() {

 // several definitions on attached

  Serial.begin(115200);

  SPIFFS.begin();

  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  Serial.println("");

  // Wait for connection
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("Connected to ");
  Serial.println(ssid);
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());

  server.on("/", handleRoot);

  server.on("/volcano.json", volcano);

  server.on("/",HTTP_GET, volcano);


  server.onNotFound(handleNotFound);

  /*server.on("/index.html", HTTP_GET, []() {

   // like volcano(), see attached 
    });*/

  server.begin();
  Serial.println("HTTP server started");

}

void loop () {
  WiFiClient(keepalive);
  WiFiClient client;

  server.handleClient();

}

void volcano() {

  StaticJsonBuffer<1174> jsonBuffer;
  JsonObject& volcano = jsonBuffer.createObject();
  volcano["width"] = 8;
  volcano["height"] = 8;
  JsonArray& analogValues = volcano.createNestedArray("values");

  for (int rowCount = 0; rowCount < 8; rowCount++) {

    r0 = metaMsk[rowPinRef[rowCount]][0];
    r1 = metaMsk[rowPinRef[rowCount]][1];
    r2 = metaMsk[rowPinRef[rowCount]][2];
    r3 = metaMsk[rowPinRef[rowCount]][3];

    digitalWrite(twoA, r0); //send to Digital OUT 1
    digitalWrite(twoB, r1); //send to Digital OUT 2
    digitalWrite(twoC, r2); //send to Digital OUT 3
    digitalWrite(twoD, r3); //send to Digital OUT 4

    for (int colCount = 0; colCount < 8; colCount++) {

      c0 = metaMsk[colPinRef[colCount]][0];
      c1 = metaMsk[colPinRef[colCount]][1];
      c2 = metaMsk[colPinRef[colCount]][2];
      c3 = metaMsk[colPinRef[colCount]][3];

      digitalWrite(oneA, c0); //send to Digital OUT 1
      digitalWrite(oneB, c1); //send to Digital OUT 2
      digitalWrite(oneC, c2); //send to Digital OUT 3
      digitalWrite(oneD, c3); //send to Digital OUT 4

      int val = analogRead(COM1);
      matrixValues[colCount] = val;
      analogValues.add(val);
    }//end for
    delay(2);
  }//end for

  output = "";
  volcano.printTo(output);
  Serial.println("volcano" + (output));
  server.send(200, "application/json", output);
  // client.println(output);

}

void handleRoot() {
  server.sendHeader("Location", "/index.html", true);  //Redirect to our html web page
  server.send(302, "text/plane", "");
}

void handleNotFound() {
  if (loadFromSpiffs(server.uri())) return;
  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);
}

bool loadFromSpiffs(String path) {
  String dataType = "text/plain";
  if (path.endsWith("/")) path += "index.htm";
  if (path.endsWith(".src")) path = path.substring(0, path.lastIndexOf("."));
  else if (path.endsWith(".html")) dataType = "text/html";
  else if (path.endsWith(".htm")) dataType = "text/html";
  else if (path.endsWith(".css")) dataType = "text/css";
  else if (path.endsWith(".js")) dataType = "application/javascript";
  else if (path.endsWith(".png")) dataType = "image/png";
  else if (path.endsWith(".gif")) dataType = "image/gif";
  else if (path.endsWith(".jpg")) dataType = "image/jpeg";
  else if (path.endsWith(".ico")) dataType = "image/x-icon";
  else if (path.endsWith(".xml")) dataType = "text/xml";
  else if (path.endsWith(".pdf")) dataType = "application/pdf";
  else if (path.endsWith(".zip")) dataType = "application/zip";
  File dataFile = SPIFFS.open(path.c_str(), "r");
  if (server.hasArg("download")) dataType = "application/octet-stream";
  if (server.streamFile(dataFile, dataType) != dataFile.size()) {
  }

  dataFile.close();
  return true;
}

I’ve tried several ways, but none of them works. What’s wrong? Note some parts are only for testing. Attached are
SPIFF files used in project.

Thank you

Toni

manta_esp8266_json.zip (76.1 KB)

Please close, I was using different server!