AN3406

Fast Prototyping of BLE Sensors for AWS Cloud Using the

ATmega4809 Curiosity Nano Development Platform

Introduction

Author: Ioan Pop, Alin Stoicescu, Microchip Technology Inc.

This application note describes how to use the ATmega4809 Curiosity Nano Development Platform to create a low-

power BLE (Bluetooth

®

Low Energy) sensor node that connects to the Amazon Web Services (AWS) Cloud through

a gateway. This document includes a detailed tutorial and links to a GitHub repository containing the documented

mikroBUS sockets are used to connect the RN4870 click board, which incorporates a Microchip RN4870 Bluetooth

Low Energy module, as well as the Weather click board, which contains a BME280 sensor to provide humidity,

temperature, and pressure readings. The application is intended to be an off-the-shelf system – each of the

components is designed for seamless prototyping on the Curiosity Nano Platform and can quickly be configured in

software through MPLAB

Figure 1. Sensor Node Block Diagram

When the application starts, the microcontroller creates three public characteristics for pressure, temperature, and

humidity data in the BLE module for the sensor data. The microcontroller reads the data from the sensor every five

seconds and updates the characteristics with the respective values. A gateway is required to transmit the information

to the cloud. The gateway establishes a connection with the BLE module of the end node and connects to the cloud

services from a local Internet network through Ethernet or Wi-Fi

®

. Every five seconds, the gateway reads the

characteristics and publishes the data to the cloud.

Application Note

AWS is used for cloud services. It provides a gateway core software called AWS IoT Greengrass that allows the

users to interact with the cloud. Publishing and subscription to topics can be done just by utilizing Application

Programming Interfaces (API) in Lambda.

The source code for peripherals used in the microcontroller is generated using MCC. The code generator creates the

structure of the project, the files, and the source code. MCC provides support for every peripheral and development

extension boards such as the RN4870 click board.

The following GitHub repository contains the project source code for the ATmega4809 Curiosity Nano board together

with the Lambda used by the gateway to read characteristics and publish the data to the cloud.