Flappy Controller v4

Current controller for the split-flap display system with color-coded character support. Receives MQTT messages from AWS IoT and distributes display data to worker boards via SerialTransfer.

This controller is actively used. See arduino_secrets.h.

Hardware

• Board: Arduino Nano 33 IoT
• Platform: atmelsam
• Additional:
  • ECCX08 crypto chip (built into Nano 33 IoT)
  • Serial1 connection to worker boards

Features

• WiFi connectivity with automatic reconnection
• Secure MQTT communication with AWS IoT using certificate-based authentication
• SerialTransfer protocol for communicating with worker boards
• Supports 40 characters (screen size)
• Extended alphabet with color-coded characters
• Per-character correction values for fine-tuning position
• Verbose logging for debugging
• LED status indicator (ON = not connected, OFF = connected)

Supported Characters

52-character extended alphabet with color support:

Characters	Description
(space)	Blank
A-Z	Uppercase letters
g	Green square
0-9	Numbers
r	Red square
.?-$'#	Punctuation
y	Yellow square
p	Purple square
,!@&	More punctuation
w	White square

MQTT Message Format

{
  "state": {
    "desired": {
      "message": "HELLO WORLD",
      "corrections": "0000000000000000000000000000000000000000"
    }
  }
}

• message: Up to 40 characters to display (case-sensitive for colors)
• corrections: Per-character position correction (0-5 steps), one digit per character

Configuration

Create include/arduino_secrets.h:

#define WIFI_SECRET_SSID "your-wifi-ssid"
#define WIFI_SECRET_PASS "your-wifi-password"
#define MQTT_AWS_NAME "your-thing-name"
#define MQTT_AWS_BROKER "your-iot-endpoint.iot.region.amazonaws.com"
#define MQTT_AWS_PUBLIC_CERTIFICATE "-----BEGIN CERTIFICATE-----\n...\n-----END CERTIFICATE-----"

Building and Flashing

# Build
pio run

# Upload
pio run --target upload

# Monitor serial output (115200 baud)
pio device monitor

Dependencies

Library	Version
powerbroker2/SerialTransfer	^3.1.2
Wire	-
arduino-libraries/WiFiNINA	^1.8.14
arduino-libraries/ArduinoMqttClient	^0.1.7
arduino/Arduino Cloud Provider Examples	^1.2.1
arduino-libraries/ArduinoBearSSL	^1.7.3
thijse/ArduinoLog	^1.1.1
arduino-libraries/Arduino_JSON	^0.2.0
bblanchon/ArduinoJson	^6.21.4

Changes from v3

This version is functionally identical to v3. Use this version for new deployments.