@ajb2k3 I’m afraid but I’m not the author of that post. But, I agree that it’s a well written one. Regarding device shadow, this is what I meant:

• Interact with device shadows

@ajb2k3 Thank you for your effort and update. The flow that I have in mind is:

Core2(Greengrass client using aws IoT device SDK) -> RaspberryPi(Greengrass) -> AWS IoT Core

The reason that I want to use this is to demonstrate the features of the AWS Greengrass like:

• ML at the edge: core2 send image to RaspberryPi(Greengrass) and run ML like object detection.
• device shadow
• device defender

You may send message to RsapberryPi(Greengrass) via mqttclient like below but you can’t use device shadow or device defender.

https://www.rosietheredrobot.com/2019/03/green-green-grass-of-home.html?m=1

I hope this give you a clear picture of what I’m trying to do.

@ajb2k3 FYI, the below are the closest attempts that I was able to find.

• Embed aws iot device sdk to Micropython as user C module - stackoverflow question
• Releasing LTS of AWS IoT Device SDK for Embedded C on ESP32

@ajb2k3 Did you have a chance to test out if there's any way to do this?

I was able to send data to AWS IoT Core using the below code. If you want to run this code from VScode + Pymakr, follow this guide: MicroPython: Program ESP32/ESP8266 using VS Code and Pymakr

import network
from umqtt.simple import MQTTClient
import time
import sys
import os
import json

# configure your wifi credentials
WIFI_SSID = "<YOUR_WIFI_SSID_GOES_HERE>"
WIFI_PASS = "<YOUR_WIFI_PASSWORD_GOES_HERE>"

# configure your iot credentials
MQTT_ENDPOINT = "XXXXXX.iot.XXXXX.amazonaws.com"
MQTT_PORT = 8883
MQTT_QOS = 0
# thing-id
MQTT_CLIENT = "mycore2"

THING_CLIENT_CERT = "/flash/res/core2-certificate.pem.crt"
THING_PRIVATE_KEY = "/flash/res/core2-private.pem.key"

# topic
MQTT_TOPIC = "mycore2/env"
MQTT_SUB_TOPIC = "mycore2/command"

info = os.uname()

def connect_to_wifi(ssid, password):
    sta_if = network.WLAN(network.STA_IF)
    if not sta_if.isconnected():
        sta_if.active(True)
        sta_if.connect(ssid, password)
        while not sta_if.isconnected():
            pass
    ip_address = sta_if.ifconfig()[0]
    return ip_address

def get_key(key_path):
    with open(key_path, "r") as f:
        key = f.read()
    return key

def connect_to_mqtt():
    print("CONNECTING TO MQTT BROKER...")
    global client
    client = MQTTClient(
        client_id=MQTT_CLIENT,
        server=MQTT_ENDPOINT,
        port=MQTT_PORT,
        keepalive=0,
        ssl=True,
        ssl_params={
            "cert": get_key(THING_CLIENT_CERT),
            "key": get_key(THING_PRIVATE_KEY),
            "server_side": False
        }
    )
    client.set_callback(subscription_call_back)
    try:
        client.connect()
        print("MQTT BROKER CONNECTION SUCCESSFUL")
    except Exception as e:
        print("MQTT CONNECTION FAILED: {}".format(e))
        sys.exit()
    client.subscribe(MQTT_SUB_TOPIC)
    print("SUBSCRIBED TO TOPIC: {}".format(MQTT_SUB_TOPIC))
    return

def subscription_call_back(topic, msg):
    # confirm state update
    print("RECEIVING MESSAGE: {} FROM TOPIC: {}".format(
        msg.decode("utf-8"), topic.decode("utf-8")))
    return

def publish_message(topic, msg, qos=MQTT_QOS):
    client.publish(
        topic=topic,
        msg=msg,
        qos=qos)
    print("PUBLISHING MESSAGE: {} TO TOPIC: {}".format(msg, topic))
    return

# connect to wifi
print("CONNECTING TO WIFI NETWORK")
ip_address = connect_to_wifi(WIFI_SSID, WIFI_PASS)
print("CONNECTED SUCCESSFULLY")
print("YOUR IP ADDRESS IS: {}".format(ip_address))

# connect to mqtt
print("CONNECTING TO MQTT BROKER")
connect_to_mqtt()
print("SUBSCRIBED TO TOPIC")
while True:
    client.check_msg()

    tf = power.getTempInAXP192()
    msg = str(json.dumps({
        "client": MQTT_CLIENT,
        "device": {
            "uptime": time.ticks_ms(),
            "hardware": info[0],
            "firmware": info[2]
        },
        "sensors": {
            "TempInAXP192": tf
        },
        "status": "online",
    }))
    publish_message(MQTT_TOPIC, msg)
    time.sleep(5)

The sample(https://github.com/aws/aws-iot-device-sdk-python-v2/blob/main/samples/basic_discovery.py) uses below imports:

import time
import json
from concurrent.futures import Future
from awscrt import io
from awscrt.mqtt import QoS
from awsiot.greengrass_discovery import DiscoveryClient
from awsiot import mqtt_connection_builder

If you run that script on core2, you will get an error because concurrent, awscrt, and awsiot don't exist in the core2. It will be great if I can make those available from core2.

Is there any way to install AWS IoT SDK to be able to use core2 as a greengrass client device?
https://docs.aws.amazon.com//greengrass/v2/developerguide/client-devices-tutorial.html#connect-client-devices-tutorial