esptool-js

To reset an ESP chip, you can use different ResetStrategy implementations depending on your hardware connection. Each strategy implements a reset() method that performs a sequence of serial control operations (DTR, RTS, and delays) via a Transport instance.

Available strategies include:

• ClassicReset: A standard sequence of DTR/RTS toggles and delays.
• UsbJtagSerialReset: Specifically for USB JTAG serial connections.
• HardReset: A simplified reset, with an optional usingUsbOtg flag for USB-OTG hardware.
• CustomReset: Allows you to define a specific sequence using a command string.

import { ClassicReset, HardReset, UsbJtagSerialReset, CustomReset } from './reset.js';

// Example: Using ClassicReset
const strategy = new ClassicReset(transport, 100);
await strategy.reset();

// Example: Using HardReset
const hardReset = new HardReset(transport, true);
await hardReset.reset();

This example demonstrates the full lifecycle: requesting a port, creating the transport/loader, connecting, reading a file, flashing, resetting, and disconnecting.

import {
  ESPLoader,
  Transport,
  LoaderOptions,
  FlashOptions,
  FlashModeValues,
  FlashFreqValues,
  FlashSizeValues,
} from "esptool-js";

async function flashFirmware() {
  try {
    // 1. Request serial port
    const port = await navigator.serial.requestPort();
    
    // 2. Create transport and loader
    const transport = new Transport(port, true);
    const esploader = new ESPLoader({
      transport,
      baudrate: 115200,
      terminal: {
        clean: () => console.clear(),
        writeLine: (data) => console.log(data),
        write: (data) => console.log(data),
      },
    });
    
    // 3. Connect to device
    const chipName = await esploader.main();
    console.log(`Connected to: ${chipName}`);
    
    // 4. Load firmware (example: from a file input)
    const fileInput = document.getElementById("firmwareFile") as HTMLInputElement;
    const file = fileInput.files[0];
    const firmwareData = new Uint8Array(await file.arrayBuffer());
    
    // 5. Flash firmware
    const flashOptions: FlashOptions = {
      fileArray: [{ data: firmwareData, address: 0x1000 }],
      flashMode: "dio" as FlashModeValues,
      flashFreq: "40m" as FlashFreqValues,
      flashSize: "4MB" as FlashSizeValues,
      eraseAll: false,
      compress: true,
      reportProgress: (fileIndex, written, total) => {
        console.log(`Progress: ${((written / total) * 100).toFixed(1)}%`);
      },
    };
    
    await esploader.writeFlash(flashOptions);
    console.log("Firmware flashed successfully!");
    
    // 6. Reset device
    await esploader.after("hard_reset");
    
    // 7. Disconnect
    await transport.disconnect();
  } catch (error) {
    console.error("Error:", error);
  }
}

Use esploader.writeFlash(flashOptions) to write binary data to the flash memory.

FlashOptions Configuration:

• fileArray: Array of { data: Uint8Array, address: number } objects.
• flashMode: One of "qio", "qout", "dio", or "dout" (FlashModeValues).
• flashFreq: One of "80m", "40m", "26m", etc. (FlashFreqValues).
• flashSize: One of "256KB", "512KB", "1MB", "2MB", "4MB", etc. (FlashSizeValues).
• eraseAll: Boolean. If true, erases the entire flash before writing.
• compress: Boolean. Whether to compress data during transfer.
• reportProgress: Callback function (fileIndex, written, total) => void.
• calculateMD5Hash: Optional callback (image: Uint8Array) => string for verification.

const firmwareData = new Uint8Array(/* your firmware binary data */);
const firmwareAddress = 0x1000;

const flashOptions: FlashOptions = {
  fileArray: [
    { data: firmwareData, address: firmwareAddress }
  ],
  flashMode: "dio" as FlashModeValues,
  flashFreq: "40m" as FlashFreqValues,
  flashSize: "4MB" as FlashSizeValues,
  eraseAll: false,
  compress: true,
  reportProgress: (fileIndex, written, total) => {
    const percent = (written / total) * 100;
    console.log(`Progress: ${percent.toFixed(1)}%`);
  },
  calculateMD5Hash: (image: Uint8Array) => {
    return "your-md5-hash";
  },
};

await esploader.writeFlash(flashOptions);

// Optional: Reset the device after flashing
await esploader.after("hard_reset");