umqtt-simple-ameba

umqtt-simple ported to the Realtek Ameba platform

This is a port of the micropython MQTT Simple implementation for the Realtek Ameba Platform

Originally this came from https://raw.githubusercontent.com/RuiSantosdotme/ESP-MicroPython/master/code/MQTT/umqttsimple.py, but I'm not sure if this is the original source.

Rationale

This exists because the Ameba socket API follows the CPython API more closely than the ESP micropython socket API. Specifically, the ameba API has send and recv rather than write and read in the more widely-used ESP micropython socket.

Also, the mechanism for connecting is different in the Ameba device. There is no getaddrinfo function, but the connect function takes two parameters being a server address and port. The server address can be a FQDN or an IP address.

But why didn't we use a more recent base

In short, because Ameba. The Ameba socket port is fairly incomplete, and doesn't have setblocking functionality.

Also, the Ameba port is a fair bit behind the upstream micropython, so doesn't at the time of writing have asyncio, so we can't use Peter Hinch's excellent mqtt_as implementation.

Known Issues

Since there's no setblocking method in the ameba socket class, the wait_msg function doesn't block. This means in the real application you'll have to poll the subscribe method continually to check for messages. Yes, I know it sucks. The long term solution will be for Realtek to have their micropython port sync'ed with upstream and use asyncio.

This will only work with a more recent (custom) build of the Realtek Ameba micropython port, due to changed socket class API between the current release dated Dec 19 2022 and the latest version.

Usage

Connect to your wifi, and ensure the broker is accessible.

# Connect to Network
from wireless import WLAN

ssid = "ssid"
pwd = "password"

wifi = WLAN(mode=WLAN.STA)
wifi.connect(ssid=ssid, pswd = pwd)

# MQTT Stuff
import simple

# Connect:
m = simple.MQTTClient("name", "brokername")
m.connect()

# Publish a message:
m.publish(b"test", b"message")

# Subscribe:
m.set_callback(print)
m.subscribe(b"test")
# Returns immediately; prints the message if on the broker