Week 15: System Integration
Note: My English writing skills are limited. For this documentation, I have used AI assistance for parts of the translation.
Date: May 6 - 13, 2026
System Diagram

The top lid holds the enclosure (XIAO ESP32C6, DC converter, relay module, atomizer controller) and two fans. Inside the tank, sensors, lighting, humidifier, and heater are connected to the control board. The XIAO ESP32C6 sends data to the NAS via MQTT, and the user controls the system from a web dashboard.
What I Have Built So Far
| Week | Output |
|---|---|
| Week 06 | Test Board (KiCad design — LED + button) |
| Week 08 | Reptile Monitor PCB (XIAO ESP32C6, Grove ×4, SMD assembly) |
| Week 09 | Input device testing (SHT31 ×2, I2C dual sensor) |
| Week 10 | Output device testing (OLED, motor driver, fan ON/OFF) |
| Week 11 | WiFi + MQTT communication, web dashboard |
| Week 14 | Production dashboard (Bootstrap + Chart.js + Flask + SQLite) |
The current control board is only a XIAO mount + Grove connection board. Power supply and output terminals are not yet integrated.
Remaining Work
1. Integration Board and Enclosure
The current board cannot handle AC power input or heater output. I need to add the following components and design a new integrated board.
| Component | Purpose |
|---|---|
| AC 100V input terminal | Connect to mains power |
| AC-DC converter 5V | Power for microcontroller and sensors |
| AC-DC converter 12V | Power for fans |
| AC 100V heater output terminal | ON/OFF control via SSR |
| Integrated PCB (new design) | Combine all components on one board |
Enclosure: I will design and build a box to hold the integrated board, power modules, and Grove relay (for output).
2. In-Tank Modules
I will 3D print the following modules to place inside the terrarium.
| Module | Purpose |
|---|---|
| Pet bottle mount | Hold the water supply bottle |
| Water dish | Drinking water for reptiles, helps with humidity |
| Ultrasonic humidifier mount | Fix the humidifier module in place |
| Temperature/humidity sensor mount | Fix the SHT31 sensor position |
| Cable guide | Organize wiring inside the tank |
3. Top Lid (Enclosure Mount)
I will design and build a top lid that attaches to the existing tank frame. All control equipment will be mounted on this lid.
| Equipment | Spec |
|---|---|
| Enclosure box | Integrated board + power modules |
| Intake fan | 12V 4-pin PWM × 1 |
| Exhaust fan | 12V 4-pin PWM × 1 |
| Power input | AC 100V connector |
| Power output | Heater terminal |
Design requirements: - Fits the existing tank frame - Can be removed without tools (for maintenance)
Methods
1. Integration Board
| Step | Tool / Method |
|---|---|
| Schematic & PCB design | KiCad (Schematic Editor → PCB Editor) |
| G-code generation | pcb2gcode |
| Board fabrication | CNC milling (same process as Week 08) |
| Component assembly | Hand soldering with a soldering iron |
2. Enclosure
| Step | Tool / Method |
|---|---|
| 3D modeling | Fusion 360 |
| Fabrication | 3D printer (Bambu Lab) |
| Material | PETG (heat and humidity resistant) |
| Assembly | M3 bolts and nuts |
3. In-Tank Modules
| Step | Tool / Method |
|---|---|
| 3D modeling | Fusion 360 |
| Fabrication | 3D printer (Bambu Lab) |
| Material | PETG (recommended for humid environments) |
4. Top Lid
| Step | Tool / Method |
|---|---|
| 2D design | JW-CAD |
| Fabrication | Laser cutter |
| Material | MDF |
| Attachment | Fits onto the existing tank frame |
5. Firmware
| Step | Tool / Method |
|---|---|
| Development | Arduino IDE |
| Board | XIAO ESP32C6 |
| Changes | Update pin assignments (D6/D7 for fan PWM, D8/D9 for TACH) |
6. System Integration
All parts are assembled and connected step by step. Each module is tested individually before full system testing. Final check: sensor → MQTT → dashboard → output control (end-to-end).
Schedule
| Phase | 5/7 | 5/14 | 5/21 | 5/28 | 5/29 | 6/1 | 6/4 | 6/7 |
|---|---|---|---|---|---|---|---|---|
| Design | May 7 – 13 | |||||||
| Build | May 14 – 28 | |||||||
| Integration | May 29 – 31 | |||||||
| Testing | Jun 1 – 3 | |||||||
| Presentation | Jun 4 – 7 | |||||||
What I Learned
- Power design is the most important part when integrating individual components into one system.
- An integrated board that handles both AC 100V and low voltage (5V / 12V) needs careful safety design.
- Writing out a clear schedule helped me see the full scope of remaining work and set priorities.