MQTT library for MicroPython on the ESP8266 and ESP32

boot.py is the MicroPython startup. The others are the MQTT demo.

boot.py
config.py
mqtt_as.py
test.py

These scripts to interact with the mosquitto MQTT broker.

pubtest
subtest

The ESP32 startup file which run our test after a short boot delay.

# This file is executed on every boot (including wake-boot from deepsleep)
#import esp
#esp.osdebug(None)
#import webrepl
#webrepl.start()
import utime
utime.sleep(4)
import test

Main executable called from startup. This demo is pulled from the README documentation with local changes.

Configure SERVER here.

from mqtt_as import MQTTClient
from config import config
import uasyncio as asyncio

SERVER = '192.168.0.13'  # Change to suit e.g. 'iot.eclipse.org'

def callback(topic, msg, retained):
    print((topic, msg, retained))

async def conn_han(client):
    await client.subscribe('foo_topic', 1)

async def main(client):
    await client.connect()
    n = 0
    while True:
        await asyncio.sleep(5)
        print('publish', n)
        # If WiFi is down the following will pause for the duration.
        await client.publish('result', '{}'.format(n), qos = 1)
        n += 1

config['subs_cb'] = callback
config['connect_coro'] = conn_han
config['server'] = SERVER

MQTTClient.DEBUG = True  # Optional: print diagnostic messages
client = MQTTClient(config)
loop = asyncio.get_event_loop()
try:
    loop.run_until_complete(main(client))
finally:
    client.close()  # Prevent LmacRxBlk:1 errors

mqtt_as configuration as found in distribution directory with mosquitto MQTT broker and wifi changes.

Configure MQTT broker, ssid and password.

# config.py Local configuration for mqtt_as demo programs.
from sys import platform
from mqtt_as import config

config['server'] = '192.168.0.13' # Change to suit
# config['server'] = 'iot.eclipse.org'

# Not needed if you're only using ESP8266
config['ssid'] = 'kewl-v8'
config['wifi_pw'] = 'PASSWORD'

# For demos ensure the same calling convention for LED's on all platforms.
# ESP8266 Feather Huzzah reference board has active low LED's on pins 0 and 2.
# ESP32 is assumed to have user supplied active low LED's on same pins.
# Call with blue_led(True) to light

if platform == 'esp8266' or platform == 'esp32' or platform == 'esp32_LoBo':
    from machine import Pin
    def ledfunc(pin):
        pin = pin
        def func(v):
            pin(not v)  # Active low on ESP8266
        return func
    wifi_led = ledfunc(Pin(0, Pin.OUT, value = 0))  # Red LED for WiFi fail/not ready yet
    blue_led = ledfunc(Pin(2, Pin.OUT, value = 1))  # Message received
elif platform == 'pyboard':
    from pyb import LED
    def ledfunc(led, init):
        led = led
        led.on() if init else led.off()
        def func(v):
            led.on() if v else led.off()
        return func
    wifi_led = ledfunc(LED(1), 1)
    blue_led = ledfunc(LED(3), 0)

mqtt_as excecutable. This is the main logic which maintains a Wifi connection and publishes and subscribes to topics.

wget https://raw.githubusercontent.com/peterhinch/micropython-mqtt/master/mqtt_as/mqtt_as.py

>>> import machine
>>> machine.reset()
ets Jun  8 2016 00:22:57

rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0018,len:4
load:0x3fff001c,len:5008
ho 0 tail 12 room 4
load:0x40078000,len:10600
ho 0 tail 12 room 4
load:0x40080400,len:5684
entry 0x400806bc
I (548) cpu_start: Pro cpu up.
I (548) cpu_start: Application information:
I (548) cpu_start: Compile time:     Aug 16 2020 00:54:20
I (551) cpu_start: ELF file SHA256:  0000000000000000...
I (557) cpu_start: ESP-IDF:          v3.3.2
I (562) cpu_start: Starting app cpu, entry point is 0x40082f30
I (552) cpu_start: App cpu up.
I (573) heap_init: Initializing. RAM available for dynamic allocation:
I (579) heap_init: At 3FFAFF10 len 000000F0 (0 KiB): DRAM
I (585) heap_init: At 3FFB6388 len 00001C78 (7 KiB): DRAM
I (591) heap_init: At 3FFB9A20 len 00004108 (16 KiB): DRAM
I (598) heap_init: At 3FFBDB5C len 00000004 (0 KiB): DRAM
I (604) heap_init: At 3FFCA9E8 len 00015618 (85 KiB): DRAM
I (610) heap_init: At 3FFE0440 len 00003AE0 (14 KiB): D/IRAM
I (616) heap_init: At 3FFE4350 len 0001BCB0 (111 KiB): D/IRAM
I (623) heap_init: At 4009DE28 len 000021D8 (8 KiB): IRAM
I (629) cpu_start: Pro cpu start user code
I (312) cpu_start: Starting scheduler on PRO CPU.
I (0) cpu_start: Starting scheduler on APP CPU.
I (4890) modsocket: Initializing
I (5020) wifi:wifi driver task: 3ffd1120, prio:23, stack:3584, core=0
I (10354) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
I (10354) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
I (10404) wifi:wifi firmware version: 44aa95c
I (10404) wifi:config NVS flash: enabled
I (10404) wifi:config nano formating: disabled
I (10404) wifi:Init dynamic tx buffer num: 32
I (10404) wifi:Init data frame dynamic rx buffer num: 32
I (10414) wifi:Init management frame dynamic rx buffer num: 32
I (10414) wifi:Init management short buffer num: 32
I (10424) wifi:Init static rx buffer size: 1600
I (10424) wifi:Init static rx buffer num: 10
I (10424) wifi:Init dynamic rx buffer num: 32
I (10534) phy: phy_version: 4180, cb3948e, Sep 12 2019, 16:39:13, 0, 0
I (10534) wifi:mode : sta (30:ae:a4:fe:03:80)
I (10534) wifi: STA_START
I (10914) wifi:new:<3,0>, old:<1,0>, ap:<255,255>, sta:<3,0>, prof:1
I (11764) wifi:state: init -> auth (b0)
I (11764) wifi:state: auth -> assoc (0)
I (11774) wifi:state: assoc -> run (10)
I (11784) wifi:connected with kewl-v8, aid = 10, channel 3, BW20, bssid = c2:4a:00:be:c7:a6
I (11794) wifi:security type: 3, phy: bgn, rssi: -57
I (11794) wifi:pm start, type: 1

I (11794) network: CONNECTED
I (11844) wifi:AP's beacon interval = 102400 us, DTIM period = 2
I (19724) event: sta ip: 192.168.0.237, mask: 255.255.255.0, gw: 192.168.0.1
I (19724) network: GOT_IP
Checking WiFi integrity.
Got reliable connection
Connecting to broker.
Connected to broker.
publish 0
publish 1

Subscribe to the topic named 'result' published by the ESP32 module and display it.

#! /bin/bash
mosquitto_sub -h 192.168.0.13 -t result

Running status for the result topic.

0
1

Publish two messages to the topic named 'foo_topic' which the ESP32 device is subscribed to,

#! /bin/bash
# mosquitto_sub -h 192.168.0.10 -t result
while :
do
    mosquitto_pub -h 192.168.0.13 -t foo_topic -m "gordon bennett" -q 1
    sleep 5
    mosquitto_pub -h 192.168.0.13 -t foo_topic -m "pete was here" -q 1
    sleep 5
done

Show running status on the ESP32 and incoming subscription topics.

publish 103
(b'foo_topic', b'gordon bennett', False)
RAM free 94032 alloc 17136
publish 104
(b'foo_topic', b'pete was here', False)
publish 105

Project page

Documentation