Graph example (#7299)

* New Graph Example

* Now using isFlashInterfacePin() no define default GPIO mask.

* Added info about zooming.

* Adressed requested changes (boolean > bool,
using esp8266::polledTimeout::periodicMs, reducing complexity)

libraries/ESP8266WebServer/examples/Graph/Graph.ino

@@ -0,0 +1,332 @@
+/*
+  Graph - A web-based Graph display of ESP8266 data
+
+  This file is part of the ESP8266WebServer library for Arduino environment.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+  See readme.md for more information.
+*/
+
+////////////////////////////////
+
+// Select the FileSystem by uncommenting one of the lines below
+
+//#define USE_SPIFFS
+#define USE_LITTLEFS
+//#define USE_SDFS
+
+////////////////////////////////
+
+#include <ESP8266WiFi.h>
+#include <WiFiClient.h>
+#include <ESP8266WebServer.h>
+#include <ESP8266mDNS.h>
+#include <SPI.h>
+
+#if defined USE_SPIFFS
+#include <FS.h>
+FS* fileSystem = &SPIFFS;
+SPIFFSConfig fileSystemConfig = SPIFFSConfig();
+#elif defined USE_LITTLEFS
+#include <LittleFS.h>
+FS* fileSystem = &LittleFS;
+LittleFSConfig fileSystemConfig = LittleFSConfig();
+#elif defined USE_SDFS
+#include <SDFS.h>
+FS* fileSystem = &SDFS;
+SDFSConfig fileSystemConfig = SDFSConfig();
+// fileSystemConfig.setCSPin(chipSelectPin);
+#else
+#error Please select a filesystem first by uncommenting one of the "#define USE_xxx" lines at the beginning of the sketch.
+#endif
+
+
+#define DBG_OUTPUT_PORT Serial
+
+#ifndef STASSID
+#define STASSID "your-ssid"
+#define STAPSK  "your-password"
+#endif
+
+// Indicate which digital I/Os should be displayed on the chart.
+// From GPIO16 to GPIO0, a '1' means the corresponding GPIO will be shown
+// e.g. 0b11111000000111111
+unsigned int gpioMask;
+
+const char* ssid = STASSID;
+const char* password = STAPSK;
+const char* host = "graph";
+
+ESP8266WebServer server(80);
+
+static const char TEXT_PLAIN[] PROGMEM = "text/plain";
+static const char FS_INIT_ERROR[] PROGMEM = "FS INIT ERROR";
+static const char FILE_NOT_FOUND[] PROGMEM = "FileNotFound";
+
+////////////////////////////////
+// Utils to return HTTP codes
+
+void replyOK() {
+  server.send(200, FPSTR(TEXT_PLAIN), "");
+}
+
+void replyOKWithMsg(String msg) {
+  server.send(200, FPSTR(TEXT_PLAIN), msg);
+}
+
+void replyNotFound(String msg) {
+  server.send(404, FPSTR(TEXT_PLAIN), msg);
+}
+
+void replyBadRequest(String msg) {
+  DBG_OUTPUT_PORT.println(msg);
+  server.send(400, FPSTR(TEXT_PLAIN), msg + "\r\n");
+}
+
+void replyServerError(String msg) {
+  DBG_OUTPUT_PORT.println(msg);
+  server.send(500, FPSTR(TEXT_PLAIN), msg + "\r\n");
+}
+
+////////////////////////////////
+// Request handlers
+
+/*
+   Read the given file from the filesystem and stream it back to the client
+*/
+bool handleFileRead(String path) {
+  DBG_OUTPUT_PORT.println(String("handleFileRead: ") + path);
+
+  if (path.endsWith("/")) {
+    path += "index.htm";
+  }
+
+  String contentType = mime::getContentType(path);
+
+  if (!fileSystem->exists(path)) {
+    // File not found, try gzip version
+    path = path + ".gz";
+  }
+  if (fileSystem->exists(path)) {
+    File file = fileSystem->open(path, "r");
+    if (server.streamFile(file, contentType) != file.size()) {
+      DBG_OUTPUT_PORT.println("Sent less data than expected!");
+    }
+    file.close();
+    return true;
+  }
+
+  return false;
+}
+
+
+/*
+   The "Not Found" handler catches all URI not explicitely declared in code
+   First try to find and return the requested file from the filesystem,
+   and if it fails, return a 404 page with debug information
+*/
+void handleNotFound() {
+  String uri = ESP8266WebServer::urlDecode(server.uri()); // required to read paths with blanks
+
+  if (handleFileRead(uri)) {
+    return;
+  }
+
+  // Dump debug data
+  String message;
+  message.reserve(100);
+  message = F("Error: File not found\n\nURI: ");
+  message += uri;
+  message += F("\nMethod: ");
+  message += (server.method() == HTTP_GET) ? "GET" : "POST";
+  message += F("\nArguments: ");
+  message += server.args();
+  message += '\n';
+  for (uint8_t i = 0; i < server.args(); i++) {
+    message += F(" NAME:");
+    message += server.argName(i);
+    message += F("\n VALUE:");
+    message += server.arg(i);
+    message += '\n';
+  }
+  message += "path=";
+  message += server.arg("path");
+  message += '\n';
+  DBG_OUTPUT_PORT.print(message);
+
+  return replyNotFound(message);
+}
+
+void setup(void) {
+  ////////////////////////////////
+  // SERIAL INIT
+  DBG_OUTPUT_PORT.begin(115200);
+  DBG_OUTPUT_PORT.setDebugOutput(true);
+  DBG_OUTPUT_PORT.print('\n');
+
+  ////////////////////////////////
+  // FILESYSTEM INIT
+
+  fileSystemConfig.setAutoFormat(false);
+  fileSystem->setConfig(fileSystemConfig);
+  bool fsOK = fileSystem->begin();
+  DBG_OUTPUT_PORT.println(fsOK ? F("Filesystem initialized.") : F("Filesystem init failed!"));
+
+  ////////////////////////////////
+  // PIN INIT
+  pinMode(4, INPUT);
+  pinMode(12, OUTPUT);
+  pinMode(13, OUTPUT);
+  pinMode(15, OUTPUT);
+
+  ////////////////////////////////
+  // WI-FI INIT
+  DBG_OUTPUT_PORT.printf("Connecting to %s\n", ssid);
+  WiFi.mode(WIFI_STA);
+  WiFi.begin(ssid, password);
+  // Wait for connection
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(500);
+    DBG_OUTPUT_PORT.print(".");
+  }
+  DBG_OUTPUT_PORT.println("");
+  DBG_OUTPUT_PORT.print(F("Connected! IP address: "));
+  DBG_OUTPUT_PORT.println(WiFi.localIP());
+
+  ////////////////////////////////
+  // MDNS INIT
+  if (MDNS.begin(host)) {
+    MDNS.addService("http", "tcp", 80);
+    DBG_OUTPUT_PORT.print(F("Open http://"));
+    DBG_OUTPUT_PORT.print(host);
+    DBG_OUTPUT_PORT.println(F(".local to open the graph page"));
+  }
+
+  ////////////////////////////////
+  // WEB SERVER INIT
+
+  //get heap status, analog input value and all GPIO statuses in one json call
+  server.on("/espData", HTTP_GET, []() {
+    String json;
+    json.reserve(88);
+    json = "{\"time\":";
+    json += millis();
+    json += ", \"heap\":";
+    json += ESP.getFreeHeap();
+    json += ", \"analog\":";
+    json += analogRead(A0);
+    json += ", \"gpioMask\":";
+    json += gpioMask;
+    json += ", \"gpioData\":";
+    json += (uint32_t)(((GPI | GPO) & 0xFFFF) | ((GP16I & 0x01) << 16));
+    json += "}";
+    server.send(200, "text/json", json);
+  });
+
+  // Default handler for all URIs not defined above
+  // Use it to read files from filesystem
+  server.onNotFound(handleNotFound);
+
+
+  // Start server
+  server.begin();
+  DBG_OUTPUT_PORT.println("HTTP server started");
+
+  DBG_OUTPUT_PORT.println("Please pull GPIO4 low (e.g. press button) to switch output mode:");
+  DBG_OUTPUT_PORT.println(" 0 (OFF):    outputs are off and hidden from chart");
+  DBG_OUTPUT_PORT.println(" 1 (AUTO):   outputs are rotated automatically every second");
+  DBG_OUTPUT_PORT.println(" 2 (MANUAL): outputs can be toggled from the web page");
+
+}
+
+// Return default GPIO mask, that is all I/Os except SD card ones
+unsigned int defaultMask() {
+  unsigned int mask = 0b11111111111111111;
+  for (auto pin = 0; pin <= 16; pin++) {
+    if (isFlashInterfacePin(pin)) {
+      mask &= ~(1 << pin);
+    }
+  }
+  return mask;
+}
+
+int rgbMode = 1; // 0=off - 1=auto - 2=manual
+int rgbValue = 0;
+esp8266::polledTimeout::periodicMs timeToChange(1000);
+bool modeChangeRequested = false;
+
+void loop(void) {
+  server.handleClient();
+  MDNS.update();
+
+  if (digitalRead(4) == 0) {
+    // button pressed
+    modeChangeRequested = true;
+  }
+
+  // see if one second has passed since last change, otherwise stop here
+  if (!timeToChange) {
+    return;
+  }
+
+  // see if a mode change was requested
+  if (modeChangeRequested) {
+    // increment mode (reset after 2)
+    rgbMode++;
+    if (rgbMode > 2) {
+      rgbMode = 0;
+    }
+
+    modeChangeRequested = false;
+  }
+
+  // act according to mode
+  switch (rgbMode) {
+    case 0: // off
+      gpioMask = defaultMask();
+      gpioMask &= ~(1 << 12); // Hide GPIO 12
+      gpioMask &= ~(1 << 13); // Hide GPIO 13
+      gpioMask &= ~(1 << 15); // Hide GPIO 15
+
+      // reset outputs
+      digitalWrite(12, 0);
+      digitalWrite(13, 0);
+      digitalWrite(15, 0);
+      break;
+
+    case 1: // auto
+      gpioMask = defaultMask();
+
+      // increment value (reset after 7)
+      rgbValue++;
+      if (rgbValue > 7) {
+        rgbValue = 0;
+      }
+
+      // output new values
+      digitalWrite(12, rgbValue & 0b001);
+      digitalWrite(13, rgbValue & 0b010);
+      digitalWrite(15, rgbValue & 0b100);
+      break;
+
+    case 2: // manual
+      gpioMask = defaultMask();
+
+      // keep outputs unchanged
+      break;
+  }
+}
+