PPP Problem on ESP32

[tirejas]

Hello, I have an ESP32 board with version 1.25.0 (2025-04-15) and the MicroPython version. When running the attached script, I get the following error:

"MPY: soft reboot

PROBLEM IN THONNY'S BACK-END: Exception while handling 'get_globals' (thonny.plugins.micropython.mp_back.ManagementError: Script produced errors).
See Thonny's backend.log for more information.
You may need to press "Stop/Restart" or hard-reset your MicroPython device and try again.
Process ended with exit code 1."

Could the soft reboot after attempting to launch PPP indicate that the PPP implementation in this version is unstable or that there is a problem with the PPP stack? Would it work with previous versions?

Script:

import machine
import time
import network
from umqtt.simple import MQTTClient
import sys

# --- CONFIGURACION PERSONAL ---
ADAFRUIT_USER = ""
ADAFRUIT_KEY = ""
FEED = ""

UART_TX = 17
UART_RX = 16
UART_BAUD = 115200
APN = ""

# --- INICIALIZA UART ---
uart = machine.UART(1, baudrate=UART_BAUD, tx=UART_TX, rx=UART_RX)

def send_at(cmd, timeout=3000):
    uart.write(cmd + b'\r\n')
    time.sleep(0.25)  # MicroPython no siempre soporta sleep_ms
    resp = b''
    start = time.ticks_ms()
    while time.ticks_diff(time.ticks_ms(), start) < timeout:
        if uart.any():
            resp += uart.read()
    try:
        decoded = resp.decode('utf-8', 'replace')
        print(decoded)
        return decoded
    except Exception as e:
        print("Error decodificando:", e)
        return ""

# --- SECUENCIA DE INICIALIZACION ---
print("Inicializando SIM800L...")
if "OK" not in send_at(b'AT'):
    sys.exit("No responde AT. Revisa conexiones y alimentación.")
if "+CPIN: READY" not in send_at(b'AT+CPIN?'):
    sys.exit("SIM no lista o sin PIN.")
send_at(b'AT+CSQ')
if "+CREG: 0,1" not in send_at(b'AT+CREG?'):
    sys.exit("No registrado en red móvil.")
if "OK" not in send_at(b'AT+CGDCONT=1,\"IP\",\"movistar.es\"'):
    sys.exit("No se configuró APN.")

# --- MARCA PARA DATOS ---
print("Marcando para datos...")
resp = send_at(b'ATD*99#', timeout=8000)
if "CONNECT" not in resp:
    sys.exit("No se recibió CONNECT. No se puede levantar PPP.")

# --- LEVANTA PPP ---
print("Levantando PPP...")
ppp = network.PPP(uart)
ppp.active(True)
ppp.connect()

for i in range(30):
    if ppp.isconnected():
        print("PPP conectada!")
        print("Datos IP:", ppp.ifconfig())
        break
    print("Esperando PPP...")
    time.sleep(1)
else:
    sys.exit("PPP no conectada.")

# --- MQTT ADAFRUIT IO ---
print("Conectando a Adafruit IO MQTT...")
client = MQTTClient("SIM800L", "io.adafruit.com", user=ADAFRUIT_USER, password=ADAFRUIT_KEY, port=1883)
try:
    client.connect()
    print("Conectado a Adafruit IO!")
    client.publish(FEED, "Hola desde SIM800L y ESP32!")
    print("Mensaje publicado en el feed:", FEED)
    client.disconnect()
except Exception as e:
    print("Error en conexión MQTT:", e)