Zone	Board	Devices	Task	Status
1	Wemos D1 Mini	Temp, LCD	Sense temp, display it, and sync to MQTT	Active
2	Wemos D1 Mini	4-Digit Display	Display device statuses from MQTT	Active
3	MEGA 2560	Power Relays, Tilt Alarm	Main power control and security	Active
4	Raspberry Pi 4	UPS HAT, Node-RED	Manages OTA updates, MQTT, and control logic	Active
5	Wemos D1 Mini	LED Matrix	Display animations and alerts from MQTT	Active
6	Wemos D1 Mini	LCD, Sound Sensor	Sense Sound, display it, and sync to MQTT	Active

The case is a modified military coin display case from Michael’s.

Blog Posts:

• Arducase V2: OTA Updates & A New Brain
• Arducase V1: The Build

Status

The project is now largely complete. The original concept of a modular, Arduino-powered display is fully realized and has been significantly improved with a centralized control system and a robust firmware update process.

Architecture

The Arducase has evolved into a client-server architecture.

• Clients: The five Arduino-based microcontrollers in their slots, responsible for sensor readings and display functions. They report their status and listen for commands via MQTT.
• Server: A Raspberry Pi running Node-RED. It serves three primary functions:
  1. MQTT Broker: Manages all communication between the modules.
  2. OTA Update Server: Hosts firmware binaries and a version manifest, allowing all modules to update themselves over the air with a simple “pull” request.
  3. Control Logic: Contains the logic for coordinating the behavior of all modules.

Power System

To improve stability and reliability, two major changes were implemented:

1. Capacitor Filtering: Each module now has electrolytic and ceramic capacitors to smooth out voltage dips and filter electrical noise, preventing random resets.
2. UPS Backup: The Raspberry Pi is equipped with a UPS (Uninterruptible Power Supply) HAT, ensuring it stays online and maintains control even if the main power is temporarily disconnected.

Drawings

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