Devlog #2: Systems Architecture & Circuit Map Complete!

Hey everyone! 🚀

After a massive coding sprint yesterday, I have successfully locked down the core codebase for Astro-Flora and finalized the official hardware circuit schematic!

Since Astro-Flora is designed to be an industrial-grade, multi-zone life support system for extreme space environments, I needed to make sure the hardware layout perfectly matches the decoupled state-machine architecture of my code.

🌌 Hardware Subsystem Breakdown

I have organized the system architecture into four dedicated operational blocks:

Sensor Array Inputs: Dual capacitive soil moisture sensors (Zone A on A0, Zone B on A1) set to monitor a desiccation threshold of 450, an atmospheric thermistor on A4, and a fluid reservoir level unit on A5 to prevent dry-pumping.

User Interface & Audio Alerts: A 16x2 LCD display running via I2C (0x27) displaying live metrics alongside custom-rendered hex glyphs (Sprout, Sun, Moon, and Critical Warning). A master piezo buzzer sits on Pin 7 for cascading acoustic transaction tones.

Digital Security Interlock: A biometric badge-swipe simulator connected to Pin 10 using internal pull-up resistors to log crew entries and exits seamlessly.

Isolated Relay Actuators A 5-channel opto-isolated relay array connected to digital pins 2, 3, 4, 5, and 6 to safely drive high-power external loads (Solenoid water valves, grow lights, radiant heaters, and CO2 circulation fans).

🛡️ Critical Engineering Safeties Added

While drafting the final blueprint, I made sure to add flyback diodes across the solenoid water valve channels. Since pumps and solenoids create heavy inductive voltage spikes when collapsing their magnetic fields, these diodes will keep the relay module and the Arduino Mega completely protected from back-EMF damage.

The schematic is officially mapped, the code compiles flawlessly, and I’m ready to advance from the Design Phase to the Building Phase as soon as the review clears!

Check out the full schematic below! 👇