ESP-01 connection problem

[emirhan44]

I need to connect esp-01 to arduino mega for a project but i gives this error:
A fatal esptool.py error occurred: Failed to connect to ESP8266: Timed out waiting for packet header

/*
    This sketch demonstrates how to scan WiFi networks.
    The API is almost the same as with the WiFi Shield library,
    the most obvious difference being the different file you need to include:
*/

#include <ESP8266WiFi.h>

void setup() {
  Serial.begin(115200);
  Serial.println(F("\nESP8266 WiFi scan example"));

  // Set WiFi to station mode
  WiFi.mode(WIFI_STA);

  // Disconnect from an AP if it was previously connected
  WiFi.disconnect();
  delay(100);
}

void loop() {
  String ssid;
  int32_t rssi;
  uint8_t encryptionType;
  uint8_t *bssid;
  int32_t channel;
  bool hidden;
  int scanResult;

  Serial.println(F("Starting WiFi scan..."));

  scanResult = WiFi.scanNetworks(/*async=*/false, /*hidden=*/true);

  if (scanResult == 0) {
    Serial.println(F("No networks found"));
  } else if (scanResult > 0) {
    Serial.printf(PSTR("%d networks found:\n"), scanResult);

    // Print unsorted scan results
    for (int8_t i = 0; i < scanResult; i++) {
      WiFi.getNetworkInfo(i, ssid, encryptionType, rssi, bssid, channel, hidden);

      // get extra info
      const bss_info *bssInfo = WiFi.getScanInfoByIndex(i);
      String phyMode;
      const char *wps = "";
      if (bssInfo) {
        phyMode.reserve(12);
        phyMode = F("802.11");
        String slash;
        if (bssInfo->phy_11b) {
          phyMode += 'b';
          slash = '/';
        }
        if (bssInfo->phy_11g) {
          phyMode += slash + 'g';
          slash = '/';
        }
        if (bssInfo->phy_11n) {
          phyMode += slash + 'n';
        }
        if (bssInfo->wps) {
          wps = PSTR("WPS");
        }
      }
      Serial.printf(PSTR("  %02d: [CH %02d] [%02X:%02X:%02X:%02X:%02X:%02X] %ddBm %c %c %-11s %3S %s\n"), i, channel, bssid[0], bssid[1], bssid[2], bssid[3], bssid[4], bssid[5], rssi, (encryptionType == ENC_TYPE_NONE) ? ' ' : '*', hidden ? 'H' : 'V', phyMode.c_str(), wps, ssid.c_str());
      yield();
    }
  } else {
    Serial.printf(PSTR("WiFi scan error %d"), scanResult);
  }

  // Wait a bit before scanning again
  delay(5000);
}

[horace]

when attempting to program the ESP-01 using the code of post 1 what ESP-01 programmer did you use?
I tend to use a esp-01-helper-v3-esp8266 because you can program and run the code without having to change switches etc then move it to the target environment for final testing

[Nick_Pyner]

Could be all to do with power and nothing to do with all that code. I don't think Mega's 3.3v pin has anywhere near the power to run an ESP8266. This is something you need to check.