M5Stack CoreS3SE DMX Controller

A portable, small-form-factor ESP32-S3 DMX512 controller built around the M5Stack CoreS3SE. It provides a battery-powered touchscreen interface for controlling a full 512-channel DMX universe, with presets, blackout, battery monitoring and support for M5Stack Unit DMX and DMX Base hardware.

Important

Recommended / tested setup: M5Stack CoreS3SE + M5Stack Unit DMX (U183) + M5GO Bottom3.

Warning

Base DMX support is currently experimental.

On the Base DMX unit tested during development, random DMX output glitches could be reproduced even with static channel values and simplified test firmware. The same CoreS3SE, fixtures and cabling operated without those glitches when using Unit DMX. This is currently being investigated with M5Stack support and should not be interpreted as a claim that all Base DMX units are affected.

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CoreS3SE + Unit DMX

CoreS3SE + Base DMX

Application Screens

Startup Screen	Main DMX Screen
Presets	Settings Screen

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Features

• Full 512-channel DMX universe
• Touchscreen channel selection and value editing
• Persistent P1-P8 presets
• Protected preset save using hold-to-save
• Preset copy and clear
• Blackout with double-tap protection
• DMX activity / heartbeat indicator
• Battery percentage display with charging and external-power indication
• Battery runtime estimation after calibration
• Low-battery visual and audible warnings
• Persistent settings storage
• Screen always-on option
• Touch and statup sounds
• Software RESTART, POWER OFF with Double-tap protection
• Separate hardware profiles for:
  • M5Stack Unit DMX U183
  • M5Stack Base DMX

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Hardware

Recommended Setup

• M5Stack CoreS3SE
• M5Stack Unit DMX U183
• M5Stack M5GO Bottom3

Experimental Hardware

• M5Stack Base DMX

The M5GO Bottom3 contains a 3.7 V / 500 mAh battery. In the tested controller configuration, practical runtime was approximately 5 hours, depending on display brightness, activity and battery condition.

Warning

Note that, battery is required for Unit DMX and an external PSU for Base DMX to to power DMX hardware!

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Functions

Presets

Eight presets are available:

P1 P2 P3 P4
P5 P6 P7 P8

Preset data is stored persistently in ESP32 NVS.

Save

Saving is protected against accidental taps.

• Select a preset
• Hold the SAVE control for approximately 1 second
• Progress is shown while holding
• Releasing early cancels the save

Copy / Clear

Long-press an occupied preset slot to open preset options.

Available operations:

• COPY
• CLEAR
• BACK

Copying is only allowed to an empty destination slot.

Clearing is protected by a hold action.

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Blackout

BLACKOUT uses double-tap protection.

First tap  -> TAP AGAIN
Second tap -> BLACKOUT

The second tap must arrive within approximately 500 ms.

When blackout is activated, the current DMX universe is preserved and zero values are transmitted.

Double-tapping again restores the previous values.

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Settings

The Settings screen provides:

Brightness

Five levels:

1 / 2 / 3 / 4 / 5

Screen Timeout

1 / 2 / 3 / 4 / ON

ON means the display remains on continuously.

Volume

Five positions:

0 / 1 / 2 / 3 / 4

0 is mute.

Software Power Controls

The Settings screen also contains:

RESTART
POWER OFF
BACK

Both RESTART and POWER OFF require a double tap within approximately 500 ms.

Before restart / shutdown, the firmware sends several all-zero DMX frames.

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Battery Monitoring

The UI displays:

• Battery percentage
• Charging status
• External-power status
• Estimated remaining runtime

Battery indicator colors:

Battery Level	Color
36-100%	Green
21-35%	Yellow
0-20%	Red

Runtime estimation begins only after enough discharge data has been collected.

The estimator uses a rolling observation window and smooths the calculated runtime so the displayed value does not jump excessively.

Low-battery warnings are generated at approximately:

• 20%
• 10%

Battery-warning tones use a fixed high warning volume independent of the normal UI volume.

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DMX Hardware Profiles

The application code is shared. Hardware-specific UART / direction-control settings are selected by the PlatformIO build environment.

Unit DMX U183

The Unit DMX is connected to CoreS3SE Port A.

Signal	CoreS3SE GPIO
DMX TX	GPIO 2
DMX RX	GPIO 1
Direction / Enable	-1
Port	Port A

The Unit DMX handles the RS-485 direction internally, therefore the firmware does not use a separate enable pin.

Example configuration:

transmitPin = GPIO_NUM_2;
receivePin  = GPIO_NUM_1;
enablePin   = -1;

Base DMX

The Base DMX uses the CoreS3 M-Bus UART / enable pins used by M5Stack's original DMX512Tools example.

Signal	CoreS3SE GPIO
DMX TX	GPIO 7
DMX RX	GPIO 10
RS485 Enable	GPIO 6

Example configuration:

transmitPin = GPIO_NUM_7;
receivePin  = GPIO_NUM_10;
enablePin   = GPIO_NUM_6;

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PlatformIO Build Environments

Environment names: (unit is default)

cores3se_unit
cores3se_base

Build Unit DMX version

pio run -e cores3se_unit

Upload Unit DMX version

pio run -e cores3se_unit -t upload

Build Base DMX version

pio run -e cores3se_base

Upload Base DMX version

pio run -e cores3se_base -t upload

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Software Dependencies

The project is built with PlatformIO and uses:

• M5Unified
• M5GFX
• esp_dmx

The current application branch was developed around esp_dmx v2.02 because it matches the API used by the original application.

CoreS3SE compatibility note

With esp_dmx v2.02 on newer ESP32-S3 toolchains, the library may require compatibility changes in dmx_ll.h for renamed ESP-IDF UART register members.

The changes used during development were:

hw->uart_idle_conf_reg_t.tx_idle_num

to:

hw->idle_conf.tx_idle_num

hw->uart_txbrk_conf_reg_t.tx_brk_num

to:

hw->txbrk_conf.tx_brk_num

and:

hw->uart_status_reg_t.rxd

to:

hw->status.rxd

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Roadmap

Possible future development:

• ESP-NOW wireless DMX transmitter mode
• Small ESP32 / AtomS3 wireless DMX receiver
• Link-quality / RSSI indicator
• Wireless receiver pairing
• Multiple receiver support
• Art-Net / sACN support
• CRMX-compatible hardware exploration
• Fixture profiles
• Named channels
• Preset export / import
• Additional battery statistics

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Original Source / Acknowledgements

This project is based on and heavily extended from the official M5Stack:

DMX512Tools example

from the:

M5Stack M5Module-DMX512 repository

The upstream M5Stack repository is distributed under the MIT License.

Many thanks to M5Stack for publishing the original DMX512Tools example and making it available for further development.

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License

This project is released under the MIT License.

Because this project is derived from M5Stack's MIT-licensed DMX512Tools example, the original M5Stack copyright and MIT license notice must be retained for portions derived from the upstream source.

A repository LICENSE file should therefore preserve the upstream MIT notice and clearly identify the additional modifications / contributions made in this project.

Example attribution wording:

Original DMX512Tools source:
Copyright (c) M5Stack

Additional modifications and project-specific code:
Copyright (c) 2026 Zoltan Somogyvari

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Contributing

Issues, test results and pull requests are welcome.

For Base DMX testing, useful reports should include:

• exact M5Stack host model
• Base DMX revision if known
• power supply
• fixture model
• termination configuration
• firmware build environment
• esp_dmx version
• whether the issue also occurs with static DMX values

Please avoid reporting a Base DMX issue as confirmed hardware failure unless the problem has been isolated with reproducible testing.

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Disclaimer

DMX512 controls lighting and related equipment. Test new firmware in a safe environment before using it during a live event.

This project is an independent community project and is not an official M5Stack product.