OTA firmware upload for Homie ESP8266

homie_upload.py

from __future__ import (
    division,
    absolute_import,
    print_function,
    unicode_literals
    )

import hashlib
import base64
import time

from paho.mqtt.client import Client


# Input parameters
device_base = 'homie/<device_name>'
firmware_file = '.pioenvs/nodemcuv2/firmware.bin'
broker_host = 'mqtt-broker.local'


with open(firmware_file, 'rb') as f:
    firmware = f.read()
checksum = hashlib.md5(firmware)

# print(repr(firmware))
print('length:', len(firmware))
print('checksum:', checksum.hexdigest())

client_id = 'homie_upload'
c = Client(client_id, clean_session=True)
c.connect(broker_host, 1883, 60)

def on_message(mqttc, obj, msg):
    print(msg.topic + " (q" + str(msg.qos) + ", r" + str(msg.retain) + ") " + repr(msg.payload))
c.on_message = on_message

c.loop_start()

c.subscribe(device_base + '/$fw/#', qos=1)
c.subscribe(device_base + '/$implementation/ota/#', qos=1)

time.sleep(10)

msg = c.publish(device_base + '/$implementation/ota/firmware',
   bytearray(firmware), qos=0, retain=True)
msg.wait_for_publish()

msg = c.publish(device_base + '/$implementation/ota/checksum',
    checksum.hexdigest(), qos=0, retain=True)
msg.wait_for_publish()

time.sleep(60)

msg = c.publish(device_base + '/$implementation/ota/firmware',
    None, qos=1, retain=True)
msg.wait_for_publish()

msg = c.publish(device_base + '/$implementation/ota/checksum',
    None, qos=1, retain=True)
msg.wait_for_publish()

c.disconnect()
time.sleep(1)

c.loop_stop()

print('DONE!')

hei Nzbuu, I am trying your script, but no OTA run in my homie firmware.. here is the log

lesjaw@cloud:~/Olmatix-OTA$ python test_ota.py
length: 359392
checksum: f21427224720c210d713d4298f97d7fc
devices/5ccf7f80ee17/$fw/checksum (q1, r1) '16da18406f464ff1cdccbc752c99a0fc'
devices/5ccf7f80ee17/$fw/name (q1, r1) 'smartadapter1ch'
devices/5ccf7f80ee17/$fw/version (q1, r1) '2.1.0'
devices/5ccf7f80ee17/$implementation/ota/enabled (q1, r1) 'true'
[Errno 104] Connection reset by peer
DONE!
lesjaw@cloud:~/Olmatix-OTA$

I wonder why the checksum is always different even though I have the same name firmware from the same arduino sketch, I only change version number incremantlly

my mistake, it is now working.. my broker setup message limit is 64Kb, the firmware is 350KB... now it seem working, i can see the firmware run..