Cloud-Connected Sphero RVR Robot with AWS IoT Core and Seeed Studio XIAO ESP32S3

#aws #iot #robotics #seeedstudio

Note: This is a simplified version of the original post. For the full version with interactive components, visit chiwaichan.co.nz.

A Sphero RVR integrated with a Seeed Studio XIAO ESP32S3 with telemetry uploaded into, and also, basic drive remote control commands received from any where leveraging AWS IoT Core.

Overview

Lately I have been aiming to go deep on AI Robotics, and last year I have been slowly experimenting more and more with anything that is AI, IoT and Robotics related; with the intention of learning and going as wide and as deep as possible in any pillars I can think of. You can check out my blogs under the Robotics Project to see what I have been up to. This year I want to focus on enabling mobility for my experiments - as in providing wheels for solutions to move around the house, ideally autonomously; starting off with wheel based solutions bought off-shelve, followed by solutions that I build myself from open-sourced projects people have kindly contirbuted online, and then ambitiously designed, 3D Printed and built all from the ground up - perhaps in a couple of years time.

This project uses a Seeed Studio XIAO ESP32S3 microcontroller to communicate with a Sphero RVR robot via UART, while simultaneously connecting to AWS IoT Core over WiFi. The system publishes real-time sensor telemetry and accepts remote drive commands through MQTT.

Hardware Components

Component	Description
Seeed Studio XIAO ESP32S3	Compact ESP32-S3 microcontroller with WiFi, 8MB flash
Sphero RVR	Programmable robot with motors, IMU, color sensor, encoders
XIAO Expansion Board	Provides OLED display (128x64 SSD1306) for status info

Hardware Wiring

Features

Real-time Telemetry

The system publishes comprehensive sensor data every 60 seconds:

IMU Data: Pitch, roll, yaw orientation
Accelerometer & Gyroscope: Motion and rotation data
Color Sensor: RGB values with confidence
Compass: Heading in degrees
Ambient Light: Lux measurements
Motor Thermal: Temperature and protection status
Encoders: Wheel tick counts
Position & Velocity: Locator data in meters

Remote Commands via MQTT

Control the RVR from anywhere using JSON commands:

Drive: Speed and heading control
Tank: Independent left/right motor control
Raw Motors: Direct motor speed control
LED Control: Headlights, brakelights, status LEDs
Navigation: Reset yaw, reset locator
Power: Wake and sleep commands

Local OLED Display

The XIAO Expansion Board's OLED display shows real-time sensor readings for local monitoring.

MQTT Message Flow

Sensor Data Pipeline

Architecture

The XIAO ESP32S3 acts as a bridge between the Sphero RVR and AWS IoT Core:

UART Communication: The ESP32S3 communicates with the RVR via UART (GPIO43/44)
WiFi Connection: Connects to local WiFi network
MQTT over TLS: Secure connection to AWS IoT Core with X.509 certificates
Bidirectional: Publishes telemetry and subscribes to command topics

Sphero RVR Protocol

The Sphero RVR uses a binary packet-based protocol over UART. Each packet contains a start-of-packet byte (0x8D), an 8-byte header with device ID and command ID, variable-length data body, checksum, and end-of-packet byte (0xD8). The RVR has two internal processors: Nordic (handles BLE, power, color detection) and ST (handles motors, IMU, encoders).