Now, I am dealing with the MQTT which publishes data of “ON” or “OFF” to Adafruit.io feeds and got an error.

What I expected from the program, the on/off buttons will; switches every second on the adafruit.io dashboard.

What I saw on the other forum provided ways to solve the problem:

1. unassigned UART0 from the REPL
2. blocking stdin to read the line which related UART.

This is my code:

from MQTT import MQTTClient
from machine import Pin
import machine
import time
import Main2
from machine import UART
import os
uart = UART(0, 115200)
os.dupterm(uart)
def sub_cb(topic, msg):
print(msg)
wlan = Main2.get_connection()
if wlan is None:
print("Could not initialize the network connection.")
while True:
pass
client = MQTTClient("Id(i think this random)", "io.adafruit.com",user="Myaccountid", password=
"AIO-key", port=1881)
client.set_callback(sub_cb)
client.connect()
client.subscribe(topic="Myaccountid∕feeds∕afeed")
while True:
print("Sending ON")
client.publish(topic="Myaccountid∕feeds∕afeed", msg="ON")
time.sleep(2)
print("Sending OFF")
client.publish(topic="Myaccountid∕feeds∕afeed", msg="OFF")
time.sleep(2)

Shell result:

Traceback (most recent call last):
File "<stdin>", line 14, in <module>
ValueError: UART(0) is disabled (dedicated to REPL)
These are libraries link of MQTT,Main2(for connecting WIFI).

1. Main2: github.com/tayfunulu/WiFiManager/blob/master/wifimgr.py
2. MQTT: github.com/pycom/pycom-libraries/blob/master/examples/mqtt/mqtt.py