ESP8266远程OTA升级

https://blog.csdn.net/xh870189248/article/details/80095139

https://www.wandianshenme.com/play/arduino-ota-arduino-ide-ota-upgrade-esp8266-application/

我这里详细地说下这里包含了啥信息！
由下面可得，不同的8266模块，其外部falsh大小决定了编译时候的user.bin路径，所以大家在此OTA升级，必须要摸清楚你买的模块是哪个falsh大小的，注意1M = 8Mbit！！！安信可的 32Mbit 其实就是 4M的falsh，类似 25Q32这样的存储芯片。

  server.on("/", HTTP_GET, []() {
      server.sendHeader("Connection", "close");
      server.send(200, "text/html", serverIndex);
    });
    server.on("/update", HTTP_POST, []() {
      server.sendHeader("Connection", "close");
      server.send(200, "text/plain", (Update.hasError()) ? "FAIL" : "OK");
      ESP.restart();
    }, []() {
      HTTPUpload& upload = server.upload();
      if (upload.status == UPLOAD_FILE_START) {
        Serial.setDebugOutput(true);
        WiFiUDP::stopAll();
        Serial.printf("Update: %s\n", upload.filename.c_str());
        uint32_t maxSketchSpace = (ESP.getFreeSketchSpace() - 0x1000) & 0xFFFFF000;
        if (!Update.begin(maxSketchSpace)) { //start with max available size
          Update.printError(Serial);
        }
      } else if (upload.status == UPLOAD_FILE_WRITE) {
        if (Update.write(upload.buf, upload.currentSize) != upload.currentSize) {
          Update.printError(Serial);
        }
      } else if (upload.status == UPLOAD_FILE_END) {
        if (Update.end(true)) { //true to set the size to the current progress
          Serial.printf("Update Success: %u\nRebooting...\n", upload.totalSize);
        } else {
          Update.printError(Serial);
        }
        Serial.setDebugOutput(false);
      }
      yield();
    });