Onboard pcb

BIRD-E (Bounded Infrared Recording Drone Ecosystem)

Purdue University — Senior Design Capstone Project (Team E04)

Semesters: Fall 2025 – Spring 2026

Mentors: Dr Phil Walter (Purdue), Shivam Duhan (Purdue), Jonathan Lane (Purdue -> Berkeley!)

The Bounded Infrared Recording Drone Ecosystem (BIRD-E) is a specialized, lightweight tethered quadcopter system equipped with night-vision capabilities. It is designed to provide rapid, temporary, and cost-effective aerial surveillance for fire departments, law enforcement, industrial engineers, and other managerial groups who may benefit from mobile sentries. By operating via a power tether, BIRD-E circumvents standard drone flight limitations of other drones in its price point (~$260).

Repository Structure

This repository consolidates all subsystems of the BIRD-E project:

• Flight-Control/ [blocked]: Firmware for the RP2350a microcontroller managing flight dynamics and sensor polling (C/C++).
• fifo-buffer/ [blocked]: Statically allocated FIFO buffer firmware module used in sensor data filtering.
• force-sensor/ [blocked]: BLDC motor thrust calibration data and analytics scripts.
• frame/ [blocked]: Chassis 3D CAD files (STEP, OBJ, STL format) for structural assembly.
• onboard-PCB/ [blocked]: KiCad 9.0 schematic and power distribution PCB design files.
• xbox-controller/ [blocked]: Laptop pilot-interface controller handler and ESP32 wireless transceiver scripts.

Technical Setup & Interfacing

1. Ground Dock & Power Delivery

1. Place the ground dock station flat. Ensure the 16 AWG power tether wire is fully housed inside and connected to the battery.
2. Connect the external high-capacity 12.6V lead-acid battery terminal block to the outside dock interface.
3. Power on the ground battery. The drone's onboard power distribution network splits the voltage rails, indicating life via a 9-LED status bank.

2. Flight Control Firmware Compilation

The firmware is built using PlatformIO targeting the custom RP2350 proton board configuration with picosdk.

# Navigate to the firmware directory
cd Flight-Control

# Build the firmware binary
pio run

# Flash the firmware via Picoprobe
pio run -t upload

3. Xbox Ground Station Interface

The pilot interfaces with the drone using a laptop running a Python-based PyGame client that streams controller commands wirelessly over Wi-Fi.

Prerequisites

• Python 3.10+
• Windows PowerShell (or Unix-based terminal)

Setup & Execution

1. Connect the laptop to the local Wi-Fi Access Point hosted directly by the drone's companion computer.
2. Plug the Xbox controller into the laptop via USB and turn it on.
3. Set up the virtual environment and launch the interface:

# Navigate to the controller directory
cd xbox-controller

# Create and activate virtual environment
python -m venv .venv
.venv\Scripts\activate  # On Linux/macOS use: source .venv/bin/activate

# Install required dependencies
pip install pygame==2.6.1

# Run the pilot-interface handler (Pi Zero 2W target)
python src/z2w/client_user.py

4. Wait for the terminal debugger console to print: Communication Established.

Flight Controls Mapping

4. Thrust Calibration Analytics

To process thrust measurement data and generate calibration curves for BLDC motor PWM duty cycles:

cd force-sensor
pip install pandas numpy matplotlib
python pwm_to_thrust.py

Hardware Architecture & Specifications

• Microcontroller: RP2350a (Proton Board clone layout)
• Companion Computer: Raspberry Pi Zero 2W (Wi-Fi AP host & command processing)
• IMU: BNO055 (or MPU 9250 during testing)
• Altimeter: MPL3115A2 / MPU L35115A2
• Chassis: TBS Source One frame (modified with custom 3D printed components found in frame/)

Known Issues

• BNO055 Sensor EOL: The BNO055 IMU is no longer manufactured; future builds should transition to an active alternative.
• Takeoff Tilt: The drone exhibits initial tilt during takeoff before PID loops stabilize orientation in mid-air. Clear surrounding space prior to lift-off. Seriously. You will hurt your finger.
• PCB USB-C Connection: The onboard custom PCB USB-C port has hardware interface issues (suspected resistor sizing). Programming can alternatively be done via debug pins.
• Battery Connection: Though not a functionality issue, our drone didn't properly connect to the battery, and was held on with C-Clamps. This was dangerous, and would spark when connecting. Consider changing this.

Contributors

• Andrew Robertson
• Ryan Wurtz
• Tiana Lin
• Zachary Hsiung
• Honorable Mentions (Not In The Team, but Large Contributors): Victor Merz (L3Harris), Niraj Menon (Purdue University)