ResQ868

Project overview

ResQ868 is my final-year prototype: a four-legged reconnaissance robot controlled from a ground station over an 868 MHz link. It integrates a Fusion 360-designed MDF and PLA chassis, 12 servos, ROS 2 Jazzy and embedded control.

The engineering

The challenge

Deliver a low-cost teleoperated reconnaissance prototype for obstructed environments, with a radio channel shared by movement commands, sensor telemetry and camera frames.

My contribution

Designed and assembled the chassis; integrated embedded motion control, sensors, radio communication, image transmission and the operator interface.

Approach & implementation

Designed the chassis in Fusion 360 and fabricated it using laser-cut MDF and 3D-printed PLA. Integrated four three-joint legs, geometric inverse kinematics and a creep gait. Connected ROS 2 on a Raspberry Pi 5 to FreeRTOS and micro-ROS on an STM32F446RE. Implemented a grayscale JPEG chunking pipeline and a Tkinter ground station. Iterated the structure, RF timing, I²C configuration and servo power distribution during testing.

Results & lessons

What the project achieved

Power stability: the report’s multimeter samples show walking-voltage range decreasing from 0.12 V to 0.06 V after buffering (50% smaller), with recorded minimum increasing from 5.76 V to 5.92 V. These are sampled DC readings, not oscilloscope measurements of fast transients. Battery: approximately 70–80 minutes of active operation, timed from full charge until the 3.3 V-per-cell alarm. Direct walking-current measurements were not taken. Communication: preliminary operation at approximately 30 m through two interior plasterboard walls. Formal range testing and a controlled 2.4 GHz comparison were not completed. Camera: approximately 0.3–0.7 fps with 100 × 75 grayscale JPEGs. Locomotion: the report records successful ascent and descent on an approximately 20° rigid ramp.

Limitations & next steps

The chassis revision isolated the electronics from servo-shaft vibration, while supply buffering reduced observed jitter. Lower image size and longer inter-chunk delays made the constrained radio link more usable. Remaining limits include lateral sway, asymmetric turning, breadboard wiring fragility, low camera update rate and uncalibrated gas readings. Rubble, wet surfaces and operational rescue conditions remain unvalidated. Camera frame-completion percentages differ between report sections, so no single completion percentage is claimed here.

Explore the engineering

Media & resources

1 / 4 · Fusion 360 assembly rendering — report Figure 1

Let’s talk about this project.

I’m happy to walk through the design decisions, challenges and what I would improve next.