🛠 Network Automation and Storage on M5Stack PaperDIY

Objectifs

This advanced tutorial aims to create an autonomous IoT node capable of collecting data via WiFi, storing it locally on a MicroSD card for persistence, and displaying a visual summary on the 4.7-inch e-paper screen. We will leverage the low-power capabilities of the ESP32-S3 SoC and the 8-bit parallel interface of the ED047TC1 screen to minimize energy impact. This use case demonstrates concurrent management of network tasks, disk writing, and display refreshing without blocking, essential for field applications.

Matériel nécessaire

• M5Stack PaperDIY Complete Kit (pre-assembled)
• MicroSD Card (FAT32, 4GB minimum) formatted
• USB-C cable for initial programming
• Arduino IDE or PlatformIO environment with M5Unified and M5GFX libraries
• Local HTTP server or API for data simulation

Étapes

1. Prepare your environment by installing M5Unified and M5GFX libraries. Ensure serial port configuration is correct for the ESP32-S3-WROOM-1 module.
2. Format the MicroSD card to FAT32 and insert it into the dedicated slot. Verify detection via the serial monitor.
3. Initialize the file system and WiFi in the setup() function. Use SD.h and WiFi.h libraries to establish connection and mount the card.
4. Configure the e-paper screen via M5GFX. Note that the 8-bit parallel interface requires precise timing; use partial refresh functions to save the 140mAh battery.
5. In the loop(), fetch JSON data from your server. Parse it and write raw values to a CSV file on the MicroSD for offline archiving.
6. Display the latest statistics on the screen. Implement deep sleep logic between cycles to optimize autonomy.

Vérification

Open the MicroSD card on a PC to confirm the presence of the CSV file with consistent timestamps. Observe the e-paper screen: updates should appear without graphical artifacts. Check consumption via a USB monitor if available; it should drop significantly during sleep phases.

Pour aller plus loin

Integrate Bluetooth 5.0 LE for wireless initial configuration. Explore partitioning the 16MB Flash memory for OTA firmware storage. Optimize C++ code to leverage the dual-core LX7 processor.