Hack the Planet

Transform your Flipper Zero into a professional-grade bioelectrical activity monitor! This application automatically detects and adapts to various hardware configurations, providing real-time monitoring of electrical signals from plants, biological samples, and other conductive materials, accompanied by dynamic audio feedback.

Key Features

• Intelligent Hardware Detection – Automatically detects amplifier boards vs direct connections
• Automatic Calibration – Self-calibrating offset compensation for amplified signals
• Dual Monitoring Modes – Direct differential measurement and amplified signal processing
• Dynamic Audio Feedback – Frequency-mapped audio with sensitivity scaling
• Real-time Visualization – Live voltage display with error indication
• Robust Error Handling – Comprehensive ADC error detection and recovery
• Adaptive Sensitivity – Threshold auto-adjustment based on detected hardware
• State Machine Architecture – Reliable operation with built-in error recovery

Hardware Configurations:

Configuration 1: Direct Connection (Basic)

Use for learning, experimentation, high-voltage signals.

GPIO Connections:

• Pin 2 (PA7) → Electrode A (Positive / Signal Input)
• Pin 8 (GND) → Electrode B (Negative / Ground Reference)

These two connections form a complete electrical circuit necessary for proper analog signal acquisition. Without a ground connection to Pin 7, the analog input on PA7 will receive a floating signal, resulting in unstable or zero voltage readings and unreliable behavior.

This configuration allows direct sensing of bioelectrical signals, such as those from plants or other natural sources, using only clip wires. Ensure electrodes are securely attached and connections are stable.

Optionally add a 10kΩ pull-down resistor between PA7 and GND for improved signal clarity. Basic shielding (e.g., foil wrapping around wires) can also help reduce noise.

Features:

• Measures differential voltage
• High noise immunity (0.1V threshold)
• Displays in microvolts (µV)

Configuration 2: Amplifier Board (Advanced)

Use for sensitive measurements, plant monitoring, research.

Amplifier Board GPIO Connections:

• Pin 2 (PA7) → Amplifier Output
• Pin 3 (PA6) → Reference/Detection Pin
• Pin 4 (PA4) & Pin 5 (PA5) → Electrodes via amplifier
• GND → Amplifier Ground (common ground)

Features:

• Millivolt-level sensitivity
• Auto offset calibration
• 10x sensitivity multiplier

Recommended Amplifier Circuit:

• INA128 or AD620-based instrumentation amplifier
• Gain: ~100–1000x
• High input impedance (>1GΩ)
• Low noise, low drift

The amplifier board design is currently in development.

Installation:

Option 1: Precompiled

• Download the latest .fap file from Releases
• Copy it to your Flipper's apps/GPIO/ folder via qFlipper

Option 2: Build From Source

• Clone the Flipper firmware repository
• Place this app into applications_user/
• Build with:

bash ./fbt fap_hack_the_planet ./fbt launch_app APPID=hack_the_planet

Usage Guide

1. Getting Started

2. Connect your electrodes (direct or amplifier)

3. Launch Hack the Planet from the GPIO apps menu

4. The app will automatically:

   • Detect configuration
   • Calibrate if necessary
   • Apply proper sensitivity

5. Press OK to begin monitoring

6. Monitoring States:

   • DETECTING – Hardware auto-detection (~2 sec)
   • CALIBRATING – Amplifier offset tuning
   • READY – Waiting for user
   • MONITORING – Active signal analysis with audio
   • ERROR – Retry/recover from ADC issues

Electrode Applications

Plants

• Ideal for pothos, philodendron, rubber plants
• Clean electrode surfaces before use
• Attach to leaves or stems
• Plants may respond to touch, music, light, etc.

Other Uses

• Galvanic Skin Response (GSR)
• Electrolyte conductivity
• Bioelectricity demonstrations
• Fruit/vegetable measurements

Technical Specifications:

Sampling & Signal

• Sample Rate: 20Hz (50ms)
• ADC: 12-bit (4096 levels)
• Voltage: 0–3.3V
• Buffer: 128 samples
• Frequency Output: 50–2000Hz

Thresholds

• Amplified: 10mV, 10x sensitivity
• Direct: 100mV, 1x sensitivity

Detection Logic

• Amplifier: 1.5–1.8V average with <50mV variance
• Auto-switch between modes

Error Handling

• ADC retries with fallback
• NaN/infinity protection
• Auto re-init and status messages

Troubleshooting:

No Hardware Detected

• Check the GPIO wiring
• Ensure the amplifier ground is connected
• Detection pin PA6 must pull low

Erratic Readings

• Clean and secure electrodes
• Avoid touching during readings
• Eliminate nearby EMI

No Audio

• Confirm the speaker is active
• Recheck voltage thresholds
• Adjust electrode placement

ADC Errors

• Restart app
• Check all GPIO cables
• Retry via the OK button

Scientific & Educational Uses:

• Circadian rhythm and environmental studies
• Plant biofeedback experiments
• Signal processing education
• Electronic circuit and ADC training
• Citizen science and agriculture research

Advanced Architecture:

• State Machine: DETECTING → CALIBRATING → READY → MONITORING → ERROR
• Signal Engine:
  • Drift-compensated baseline
  • Δ voltage detection
  • Real-time frequency mapping
  • Mode-dependent display scaling

Contributing:

I welcome pull requests and suggestions!

Focus areas:

• Multi-channel signal support
• Amplifier profile library
• Mobile integration and export
• Data logging tools

License:

MIT License – open source hardware and software encouraged

Safety & Disclaimers:

• Use low voltage only (<5V)
• Do not damage living plants
• Not a medical device
• Data is for educational use only