An open-source ESP32-based platform combines GPS, inertial sensing, wireless telemetry, and onboard data logging to analyse the performance of RC cars and other radio-controlled vehicles.
Open RC Spotter is an open-source telemetry and data logging solution designed for RC cars, trucks, and other radio-controlled vehicles. The system is based on the ESP32-WROOM-32E module and includes GPS position tracking, acceleration and gyroscope data, steering and throttle data, battery voltage and temperature monitoring, and lap timing.
The hardware components of the system include a u-blox MAX-M10S GNSS receiver, a six-axis inertial measurement unit, an ADS1115 ADC for battery voltage and thermistor monitoring, an infrared receiver for lap counting, and a microSD card slot for high-speed CSV logging. Three PWM input channels monitor steering, throttle and auxiliary receiver signals, while the USB Type-C port is used for power delivery, configuration, and serial data communication.
The firmware is written in C++ and can be compiled using the Arduino IDE. The firmware includes a built-in 10-state Extended Kalman Filter (EKF) that combines GPS and IMU data to improve the accuracy of position, velocity, and attitude estimates. During the operation, the data from the sensors is recorded to the microSD card at a default sampling rate of 100 Hz in CSV format.
Following each recording session, the device creates a Wi-Fi SoftAP, allowing users to download log files from within a web browser without removing the microSD card. Live telemetry via ESP-NOW is also supported through a second ESP32 configured as a receiver to transmit the telemetry data to Open RC Crew Chief.
Open RC Spotter being an open-source project allows access to hardware design files, firmware, Arduino libraries, and even setup documentation. By combining onboard sensing, wireless communication, and data analysis in one small package, this project provides a flexible solution to developers and RC enthusiasts alike.
