RC Crawler Telemetry PCB

RC Crawler Telemetry Platform

Project Status: ✅ Completed — Fully Operational

Custom 1/10-scale RC crawler integrating a custom KiCad PCB, ESP32 firmware, real-time sensor acquisition, Bluetooth Low Energy (BLE), and a Flutter mobile telemetry dashboard.

Custom RC Crawler	Live Telemetry Dashboard

Overview

The RC Crawler Telemetry Platform is a complete embedded system designed to collect and display real-time vehicle data during operation.

An ESP32 integrated with a custom-designed KiCad PCB collects battery voltage, motor temperature, wheel RPM, and vehicle orientation. The firmware processes the sensor data, calculates vehicle speed, and transmits telemetry over Bluetooth Low Energy (BLE) to a custom Flutter/Dart mobile application.

The project covers the complete engineering workflow from mechanical fabrication and PCB design to embedded firmware, mobile development, hardware debugging, and real-world vehicle testing.

Problem

Hobby-scale RC vehicles provide limited visibility into important operating data such as temperature, battery voltage, speed, and vehicle orientation.

I built this platform to provide real-time onboard diagnostics through a wireless mobile dashboard.

Project Highlights

• Designed and assembled a custom KiCad PCB
• Developed modular C++ firmware for the ESP32
• Integrated BNO055, DS18B20, Hall-effect, and voltage sensors
• Implemented real-time RPM and vehicle-speed calculations
• Developed wireless telemetry using Bluetooth Low Energy (BLE)
• Built a custom Flutter/Dart mobile dashboard
• Fabricated a custom MIG-welded steel chassis
• Validated the complete system through real-world ground testing

System Architecture

Battery Voltage ─┐
Motor Temp ──────┤
Wheel RPM ───────┼──> ESP32 + Custom PCB ──> BLE ──> Flutter Dashboard
Pitch / Roll ────┘

Live Telemetry

🎥 Demo Videos

Ground Test — Full System

Real-world vehicle test demonstrating the custom PCB, ESP32 firmware, onboard sensors, BLE telemetry, and Flutter dashboard operating together on the crawler.

▶ Watch Ground Test on YouTube

Lifted-Wheel Telemetry Test

Controlled drivetrain test demonstrating live RPM, calculated speed, battery voltage, motor temperature, pitch, and roll telemetry.

Maximum Calculated Unloaded Wheel Speed: 17.28 mph

▶ Watch Lifted-Wheel Telemetry Test on YouTube

Note: 17.28 mph represents unloaded calculated wheel speed, not verified ground speed.

Engineering Challenge

During vehicle integration, the ESP32 began overheating and eventually stopped communicating. After replacing the ESP32, the same failure occurred again.

I systematically isolated the problem using a digital multimeter by:

• Measuring power rails throughout the custom PCB
• Correcting the buck converter output to a regulated 5.0 V
• Checking continuity and resistance between the ESP32 3.3 V rail and ground
• Testing the PCB independently from the ESP32
• Isolating and testing the battery-voltage sensing circuit

Testing revealed that the PCB's original two-resistor voltage divider was not reducing the battery-sense voltage correctly, allowing excessive voltage to reach the ESP32.

I replaced the original voltage-divider implementation with the external voltage-sensor module used during the project's prototype stage. The module safely scales the battery voltage before the signal reaches the ESP32 ADC.

After implementing the fix, I restored and validated the complete telemetry system.

Result: Identified a repeated hardware failure, isolated the faulty subsystem, modified the circuit, and restored full system operation through measurement-driven troubleshooting.

Tech Stack

Embedded: C++, ESP32, PlatformIO, Arduino Framework

Wireless: Bluetooth Low Energy (BLE)

Sensors: BNO055, DS18B20, Hall-effect sensor, voltage sensing

PCB: KiCad, schematic capture, PCB layout, soldering

Mobile: Flutter, Dart

Mechanical: MIG welding, custom steel chassis fabrication

Tools: Git, GitHub, VS Code, digital multimeter

Repository Structure

├── firmware/       # ESP32 C++ firmware
├── hardware/       # KiCad PCB files, BOM, pinout & wiring
├── mobile_app/     # Flutter/Dart telemetry application
├── docs/           # Development & testing documentation
├── photos/         # Build and system photos
├── Videos/         # Demonstration videos
└── README.md

Project Outcome

Successfully designed, fabricated, programmed, debugged, and tested a complete embedded telemetry platform capable of collecting, processing, transmitting, and displaying real-time vehicle data during operation.