esp32 OTA micropython

可以使用 MicroPython 的 OTA（Over-The-Air）功能来更新 ESP32 的固件。以下是一个简单的示例代码：

import network
import time
import urequests
import uos
import machine
import binascii
import ubinascii
import uhashlib

# WiFi 配置
ssid = 'your_wifi_ssid'
password = 'your_wifi_password'

# 固件更新地址
update_url = 'http://your_firmware_update_url'

# 获取 ESP32 的唯一标识符
def get_unique_id():
    mac = ubinascii.hexlify(network.WLAN().config('mac'), ':').decode()
    return uhashlib.sha256(mac.encode()).digest()

# 获取当前固件版本
def get_firmware_version():
    with open('version.txt', 'r') as f:
        version = f.read().strip()
    return version

# 下载新固件
def download_firmware():
    print('Downloading firmware...')
    response = urequests.get(update_url)
    with open('firmware.bin', 'wb') as f:
        f.write(response.content)
    response.close()

# 更新固件
def update_firmware():
    print('Updating firmware...')
    with open('firmware.bin', 'rb') as f:
        firmware = f.read()
    with open('firmware.bin', 'wb') as f:
        f.write(b'')
    with open('firmware.bin', 'wb') as f:
        f.write(firmware)
    machine.reset()

# 连接 WiFi
def connect_wifi():
    print('Connecting to WiFi...')
    sta_if = network.WLAN(network.STA_IF)
    sta_if.active(True)
    sta_if.connect(ssid, password)
    while not sta_if.isconnected():
        time.sleep(1)
    print('WiFi connected:', sta_if.ifconfig())

# 主程序
def main():
    connect_wifi()
    unique_id = binascii.hexlify(get_unique_id()).decode()
    print('ESP32 unique ID:', unique_id)
    current_version = get_firmware_version()
    print('Current firmware version:', current_version)
    download_firmware()
    new_version = get_firmware_version()
    print('New firmware version:', new_version)
    if new_version > current_version:
        update_firmware()
    else:
        print('No firmware update available.')

if __name__ == '__main__':
    main()

这个示例代码使用 MicroPython 的网络库和文件操作库来实现 OTA 功能。它首先连接到 WiFi，然后获取 ESP32 的唯一标识符和当前固件版本。接着它从指定的固件更新地址下载新固件，并检查新固件的版本是否比当前固件版本高。如果是，它将新固件写入 ESP32 的闪存，并重启 ESP32 来启动新固件。否则，它将不执行任何操作。

请注意，这个示例代码仅供参考，实际应用中可能需要根据具体情况进行修改和优化。