PennAiR Custom Thrust Stand with DAQ

A complete thrust testing system with real-time GUI visualization for measuring load, motor RPM, voltage, current, and temperature during motor testing.

Features

• Live Data Visualization: Real-time graphs of thrust, RPM, temperature, voltage, current, and power
• Flexible Display: Toggle individual graphs on/off with checkboxes
• Hover Readout: Crosshair + marker with x,y values that snap to nearest data point
• History Tab: Browse past CSVs, view plots and raw data table, refresh to rescan files
• Metadata in CSV: Enter Motor and Propeller; values are included at top of CSV export
• Data Export: Save test results to CSV for analysis
• Professional GUI: Interface built with PyQt5
• Comprehensive Sensing: Thrust, RPM, temperature, voltage, current (with computed power)

Hardware

• HX711 Load Cell Amplifier + Load Cell
• DHT11 Temperature Sensor
• ACS712 30A Current Sensor (We will proably switch this out for a sensor that can take higher current)
• Hall Effect Sensor
• 0–25V Voltage Sensor
• Arduino ESP32

Wiring Guide

HX711 Load Cell Amplifier

• VCC -> VCC
• GND -> GND
• DT -> D0
• SCK -> D1

Load Cell Wires:

• Red -> E+
• Black -> E-
• White -> A-
• Green -> A+

DHT11 Temperature Sensor

• VCC -> 5V
• DATA -> D4
• GND -> GND

Hall Effect RPM Sensor

• VCC -> 5V
• GND -> GND
• Signal -> D5

ACS712 Current Sensor

• VCC -> 5V
• GND -> GND
• OUT -> A0

Current Measurement Wiring:

• Power Supply (+) -> Motor (+)
• Power Supply (–) -> ACS712 -> Motor (–)

Voltage Sensor (0–25V DC)

• VCC -> 5V
• GND -> GND
• OUT -> A2

Voltage Measurement Wiring :

• VIN+ -> Voltage Source Positive
• VIN- -> Voltage Source Ground

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Software Setup

Step 1: Arduino Setup

1. Install Arduino IDE (if not already installed)

2. Install Required Libraries:

   • HX711_ADC
   • DHT sensor library

   Go to: Sketch → Include Library → Manage Libraries and search for each

3. Upload Arduino Code:

   • Open ThrustTestingAllSensors in Arduino IDE
   • Select Board: ESP32 Dev Module
   • Select the correct COM port
   • Click Upload

4. Calibrate Sensors (via Arduino Serial Monitor at 9600 baud):

   • Enter the number of magnets in your motor
   • Press t to tare the load cell (with no weight)
   • Press z to zero the current sensor (with no current flowing)
   • Important: Close Serial Monitor when done!

Step 2: Python GUI Setup

1. Navigate to Project Directory:

   cd \copy\to\your\path

2. Install Python Dependencies:

   pip install -r requirements.txt

   This installs:

   • PyQt5 (GUI framework)
   • pyqtgraph (real-time plotting)
   • pyserial (serial communication)
   • numpy (data processing)

3. Run the GUI:

   python thrust_gui.py

Step 3: Running a Test (Live Tab)

1. Connect to Arduino:

   • Select your COM port from the dropdown (e.g., COM10)
   • Click "Refresh Ports" if you don't see your device
   • Click "Connect"
   • Status should show "Connected" in green

2. Start Data Collection:

   • Click "Start Test"
   • All graphs will begin updating in real-time

• Use checkboxes to show/hide specific measurements:
  • ☑ Thrust (g)
  • ☑ RPM
  • ☑ Temperature (°C)
  • ☑ Voltage (V)
  • ☑ Current (A)
  • ☑ Power (W)
• Hover over a graph to see a crosshair and dot marker; the label shows the nearest data point’s x and y

3. Stop and Export:
   • Click "Stop Test" when finished

• Optional: Click "Auto-Scale All" (larger "A" button) to fit axes to the full run
• Click "Export to CSV" to save your data
• Choose a filename and location
• Data is saved with timestamp and ready for analysis

Step 4: Viewing Past Tests (History Tab)

1. Open the "History" tab
2. Click "Refresh" to rescan for thrust_test_*.csv files in the project directory
3. Select a CSV to view
   • Plots for thrust, RPM, temperature, voltage, current, and computed power
   • Raw data table with all rows
4. Hover over plots to see snapped x,y readouts with markers

Troubleshooting

"Access is denied" / "PermissionError"

• Cause: Another program is using the serial port
• Solution:
  • Close Arduino IDE Serial Monitor
  • Close any other serial terminal programs
  • Unplug and replug the Arduino USB cable
  • Click "Refresh Ports" in the GUI

No Data Appearing

• Verify Arduino is running (LED should blink)
• Check sensor connections
• Test with Arduino Serial Monitor first to verify data output
• Ensure baud rate is 9600

Graphs Not Updating

• Make sure you clicked "Start Test"
• Check that checkboxes are enabled for desired graphs
• Verify Arduino is sending data continuously

Project Files

Arduino Code

• ThrustTestingAllSensors - Main sensor reading code (most current)
• ThrustSensorsCurrentVoltage - Alternative version with button control

Python GUI

• thrust_gui.py - Main GUI application
• serial_reader.py - Serial communication handler
• requirements.txt - Python dependencies
• README_GUI.md - Detailed GUI documentation

CSV Export Format

Each CSV includes optional metadata rows, a blank spacer row, then the data header and rows:

Motor,TMotor 2820
Propeller,APC 10x4.7
Exported,2025-11-01 17:45:12

Time (s),Thrust (g),RPM,Temperature (°C),Voltage (V),Current (A),Power (W)
0.000,0.000,0.0,25.00,12.000,0.000,0.000
0.100,12.345,5500.0,25.10,12.050,2.456,29.622
...

Notes:

• Power (W) is included as a CSV column (Voltage × Current per sample).
• Hover readouts in the app snap to the nearest plotted data point for precise values.

Serial Commands (Arduino)

When connected via Serial Monitor:

• t - Tare load cell
• r - Recalibrate load cell
• c - Change calibration factor
• z - Zero current sensor