Showing posts with label AWS IoT. Show all posts
Showing posts with label AWS IoT. Show all posts

Tuesday, April 16, 2024

Getting Started with AWS IoT on OpenWrt Routers

While the internet is flooded with hello-world examples and simulations demonstrating the connection and message exchange between AWS-IoT Devices and AWS-IoT-Core using various programming languages like Python, C, C++, and Java, some of us beginners, students, or enthusiasts find true satisfaction in delving into the world of connected devices through hands-on interactions with physical components. The real excitement lies in experiencing the tangible effects firsthand, rather than merely observing basic hello-world messages on a computer screen.

Demo Video

How It Works

In this video, I introduce an engaging approach for exploring AWS-IoT connectivity and its real-world implications using affordable and readily available hardware components sourced from online stores. For this demonstration, I use an affordable (~$30) GL.iNet pocket router as an IoT End-Node.

This router runs on a custom-built OpenWRT Linux image and hosts an AWS IoT device agent service based on the aws-iot-device-sdk-cpp-v2. The WebUI of this custom Linux image allows you to easily configure and provision AWS IoT-specific settings such as:

  • Device certificates and private keys
  • AWS IoT Endpoints
  • Publish/subscribe topic trigger events
  • Custom scripts to control hardware accessories (switches, relays, LEDs, sensors)

Sunday, October 09, 2022

$30 Pocket Router as an AWS IoT Edge Device

How to flash a ~$30 GL.iNet MT300N-V2 pocket router with a custom OpenWrt image that includes the AWS IoT Device SDK and an aws-iot-pubsub-demo application — turning it into an AWS IoT Edge device that can feed local sensor data to the cloud.

GL.iNet MT300N-V2 pocket router as AWS IoT Edge device

GL.iNet MT300N-V2 pocket router — ready to become an AWS IoT Edge device.

Quick overview

Three steps to turn your pocket router into an AWS IoT Edge device:

  1. Flash the OEM firmware with the custom gl-mt300nv2-awsiot-demo.bin
  2. Upload your AWS-generated device certificate and private key via the web UI
  3. Reboot and watch Hello World messages published to your AWS IoT Core

Flashing the firmware

Step 1 — Connect your PC to the pocket router via Ethernet and power it on. Wait for the LED to stop blinking.

Setup diagram — PC connected to pocket router

Setup: PC connected to the pocket router via Ethernet cable.

Step 2 — Open http://192.168.8.1/cgi-bin/luci/admin/system/flashops in your browser (or follow GL.iNet's onboarding process).

Step 3 — Find the firmware upgrade menu and flash with gl-mt300nv2-awsiot-demo.bin.

Important: Disable "Keep settings" — you want to start with default settings.

Step 4 — Wait about 2 minutes until the LEDs stop blinking.

Step 5 — Disconnect and reconnect the Ethernet cable on your PC so it gets a new IP in the 192.168.20.x range.

Step 6 — Navigate to http://192.168.20.1 — you should see the new web UI:

Custom firmware web UI

Custom firmware web UI after successful flash.

AWS IoT configuration

Step 7 — Upload your device certificate and private key files through the web UI:

Certificate and key upload page

Upload your AWS-generated device certificate and private key.

Step 8 — Go to AWS-IoT → Service Settings, enter your endpoint, and click Save & Apply.

Before clicking Save & Apply, ensure your security policies on console.aws.amazon.com are set up correctly (see Step 10 below).

AWS IoT service settings page

Service Settings — enter your AWS IoT endpoint here.

Step 9 — Check the Service Log. If everything is configured correctly, you should see a "connection success" message:

Service log showing connection success

Service Log — "connection success" confirms the router is connected to AWS IoT Core.

Step 10 — On console.aws.amazon.com, ensure your security policies are set correctly:

AWS IoT security policies

AWS IoT security policies — required permissions for the device.

Testing publish and subscribe

Step 11 — On console.aws.amazon.com, subscribe to topic test/topic to see Hello World messages published from your pocket router. By default, the demo publishes 10 messages at 5-second intervals. To publish continuously, increase the Publish Count in the Service Settings page.

AWS IoT Core showing Hello World messages

AWS IoT Core — Hello World messages arriving from the pocket router.

Step 12 — To test the subscribe action, publish a JSON message to topic test/topic_led from the AWS console to control the router's LED:

{"powerstate" : "on"}
{"powerstate" : "off"}
Publishing LED control messages from AWS console

Publishing LED control commands from the AWS IoT console.

Other use cases

The pocket router can act as a gateway between AWS IoT Core and local Wi-Fi or USB-connected devices:

Use case diagram — pocket router as IoT gateway

Possible use cases — the pocket router bridges local devices to AWS IoT Core.

SOURCE CODE

github.com/hackboxguy/openwrt-wrapper — build instructions and sources

gl-mt300nv2-awsiot-demo.bin — pre-built firmware image

Saturday, September 24, 2022

AWS IoT on Raspberry Pi with 25 MB Buildroot Linux

Six simple steps to get an AWS IoT Device SDK demo running on a Raspberry Pi 4 — using a lightweight custom Linux image built with Buildroot (just under 25 MB).

Quick start

  1. Download sdcard-pi4-aws-iot-demo.img.xz (~25 MB)
  2. Write the image to an SD card using Balena Etcher
  3. Unplug and re-plug the SD card so the boot partition appears on your PC
  4. Open aws-iot-pubsub-agent.conf and set your AWS IoT endpoint
  5. Copy your AWS-generated device certificate (xyz-certificate.pem) and private key (xyz-private.pem.key) to the boot partition
  6. Insert the SD card into the Raspberry Pi 4, power on — the aws-iot-pubsub-agent will start publishing messages to your AWS IoT Core

The following image shows steps 4, 5, and 6 in detail:

SD card configuration — endpoint, certificates, and boot

Steps 4–6: configure endpoint, copy certificates, and boot the Pi.

AWS cloud preparation

Before booting the Pi, set up the following on console.aws.amazon.com:

  1. Create an AWS IoT account (payment details required even for the free tier)
  2. Navigate to IoT Core
  3. Go to Manage → All Devices → Things → Create Thing
  4. Download the device certificate and private key (copy these to the SD card boot partition as described in step 5 above)
  5. Go to Settings and note your Endpoint (needed for step 4 above)
  6. Go to Security → Policies and create a policy with 4 entries as shown below:
AWS IoT security policy configuration

AWS IoT security policy — required permissions for the device.

Building the image from source

Two commands to build the SD card image (detailed instructions in the git repository):

make -C buildroot BR2_EXTERNAL=../ BR2_DL_DIR=../../br-dl O=../../br-output raspberrypi4_aws_iot_defconfig
make -C buildroot BR2_EXTERNAL=../ BR2_DL_DIR=../../br-dl O=../../br-output

Buildroot customizations

Key changes in the Raspberry Pi 4 Buildroot config for this AWS demo image:

  1. Enabled Dropbear SSH for remote debugging without monitor/keyboard
  2. Added Buildroot package for aws-iot-device-sdk-cpp-v2
  3. Added Buildroot package for aws-iot-pubsub-agent
  4. Enabled chrony for time sync (required for TLS handshake)
  5. Enabled SDK dependencies (host-cmake, libcurl, openssl, util-linux)
  6. Included AmazonRootCA1.pem in /etc/
  7. Added aws-iot-pubsub-agent.conf to rootfs for the agent startup script
  8. Added /etc/init.d/S03MountBoot to mount the boot partition at /mnt/certs (contains certificates, key, and config)
  9. Included startup script for aws-iot-pubsub-agent

After booting

  1. Connect the Raspberry Pi 4 to a DHCP network with internet access
  2. Find the Pi on your network using hostname buildroot or its assigned IP
  3. Log in via SSH: ssh root@192.168.x.y (password: brb0x)
  4. Check the publish log: cat /tmp/aws-iot-pubsub-agent.log
  5. To modify the aws-iot-pubsub-agent code, see how to cross-compile and run on target

If everything is configured correctly (SD card and AWS security policies), Hello World! messages will appear on your AWS IoT Core console:

AWS IoT Core showing Hello World messages from Raspberry Pi

AWS IoT Core — Hello World messages arriving from the Raspberry Pi 4.

SOURCE CODE

github.com/hackboxguy/br-wrapper — build instructions and Buildroot config

sdcard-pi4-aws-iot-demo.img.xz — pre-built SD card image (~25 MB)