DropCeiling Arduino Library

DropCeiling is an Arduino library for the 8-channel Drop Ceiling 0-10V controller. It allows control via Art Net over Ethernet or WiFi, Serial, BLE, or as a standalone controller.

Supported Modes

Mode	Constructor value	Input format
Ethernet ArtNet	DropCeilingMode_Ethernet	ArtDmx over WIZ5500 UDP port 6454
WiFi ArtNet	DropCeilingMode_WiFi	ArtDmx over ESP32 WiFi UDP port 6454
BLE	DropCeilingMode_Bluetooth	One writable 8-byte BLE characteristic
Serial	DropCeilingMode_Serial	Newline-terminated CSV values
Standalone	DropCeilingMode_Standalone	Config defaults and direct API writes

Public channel numbers are 1-8. ArtNet start-channel configuration remains 0-indexed to match DMX packet offsets.

Basic Use

#include <DropCeiling.h>

DropCeiling ceiling(DropCeilingMode_Ethernet);

void setup() {
  Serial.begin(115200);
  ceiling.setup();
}

void loop() {
  ceiling.read();
}

Manual output writes use the same output path as all input modes:

ceiling.voltageWrite(1, 128);   // channel 1, logical 0-255
ceiling.voltageWrite(2, 5.0f);  // channel 2, 0.0-10.0 volts

Configuration

Use DropCeilingConfig when you need to override defaults:

DropCeilingConfig config;
config.artnetUniverse = 0;
config.i2cSdaPin = 42;
config.i2cSclPin = 41;
config.displayMode = DropCeilingDisplay_Auto;

DropCeiling ceiling(DropCeilingMode_Ethernet, config);

The defaults preserve the original controller sketch behavior: DHCP with static fallback, WIZ5500 CS pin 10, DAC6578 address 0x4C, 10-bit DAC output, ArtNet universe 0, 8 channels, and a 3-second live-signal timeout.

BLE Contract

The BLE mode creates one service and one characteristic. The characteristic accepts exactly one 8-byte payload, where byte 0 controls output 1 and byte 7 controls output 8.

Defaults:

Item	UUID/name
Device name	DropCeiling
Service UUID	7b4f0001-3f3a-4f6f-9b0d-84e8f64f0f10
Characteristic UUID	7b4f0002-3f3a-4f6f-9b0d-84e8f64f0f10

This shape is designed for Web Bluetooth clients, including p5.ble.js.

Serial CSV

Serial mode reads newline-terminated CSV strings:

0,128,255,0,0,0,0,0

Values are clamped to 0-255. By default, a short line updates only the channels provided.

Examples

• examples/EthernetArtNet
• examples/WiFiArtNet
• examples/BluetoothInput
• examples/SerialInput
• examples/Standalone

From the repository root, compile an example with:

arduino-cli compile --fqbn esp32:esp32:adafruit_feather_esp32s3_tft --libraries .. examples/EthernetArtNet

Control Software

Non-Arduino controller examples are included under extras/control-software/. Keeping them in extras/ preserves the standard Arduino library structure while packaging examples for ArtNet Ethernet, ArtNet WiFi, BLE, Serial CSV, and Standalone modes.

Project Context

See PROJECT_CONTEXT.md for the hardware background, source-repo history, compatibility notes, and next engineering steps.