DMX512 Unit

DMX Unit is a communication unit specifically designed for DMX-512 data transmission scenarios. It integrates the CA-IS3092W isolated half-duplex RS-485 transceiver, providing up to 5kVrms electrical isolation protection. The onboard 120Ω termination resistor switch matches the characteristic impedance of the signal transmission line, preventing signal reflection and distortion, and can be connected according to the usage scenario.

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dmx

Micropython Example Send Data:

 1# SPDX-FileCopyrightText: 2024 M5Stack Technology CO LTD
 2#
 3# SPDX-License-Identifier: MIT
 4
 5import os, sys, io
 6import M5
 7from M5 import *
 8from unit import DMX512Unit
 9import time
10
11
12Title = None
13label1 = None
14label0 = None
15dmx_0 = None
16
17
18ch_data = None
19
20
21def setup():
22    global Title, label1, label0, dmx_0, ch_data
23
24    M5.begin()
25    Widgets.fillScreen(0x222222)
26    Title = Widgets.Title("DMX512Unit Send example", 3, 0xFFFFFF, 0x0000FF, Widgets.FONTS.DejaVu18)
27    label1 = Widgets.Label("Not Sent", 2, 129, 1.0, 0xFFFFFF, 0x222222, Widgets.FONTS.DejaVu18)
28    label0 = Widgets.Label(
29        "Not initialized", 2, 76, 1.0, 0xFFFFFF, 0x222222, Widgets.FONTS.DejaVu18
30    )
31
32    dmx_0 = DMX512Unit(1, port=(13, 14), mode=1)
33    label0.setText(str("Initialized"))
34    ch_data = 0
35
36
37def loop():
38    global Title, label1, label0, dmx_0, ch_data
39    M5.update()
40    label1.setText(str("Not Sent"))
41    dmx_0.write_data(1, ch_data)
42    dmx_0.write_data(2, ch_data)
43    dmx_0.write_data(3, ch_data)
44    ch_data = (ch_data if isinstance(ch_data, (int, float)) else 0) + 1
45    if ch_data >= 255:
46        ch_data = 0
47    label1.setText(str("Sent"))
48    time.sleep(0.7)
49
50
51if __name__ == "__main__":
52    try:
53        setup()
54        while True:
55            loop()
56    except (Exception, KeyboardInterrupt) as e:
57        try:
58            from utility import print_error_msg
59
60            print_error_msg(e)
61        except ImportError:
62            print("please update to latest firmware")

Micropython Example Receive Data:

 1# SPDX-FileCopyrightText: 2024 M5Stack Technology CO LTD
 2#
 3# SPDX-License-Identifier: MIT
 4
 5import os, sys, io
 6import M5
 7from M5 import *
 8from unit import DMX512Unit
 9
10
11Title = None
12label0 = None
13label1 = None
14dmx_0 = None
15
16
17dmx_data = None
18dmx_data2 = None
19
20
21def dmx_0_channel1_receive_event(received_data):
22    global Title, label0, label1, dmx_0, dmx_data, dmx_data2
23    dmx_data = received_data
24    label0.setText(str((str("Channel 1:") + str(dmx_data))))
25
26
27def dmx_0_channel2_receive_event(received_data):
28    global Title, label0, label1, dmx_0, dmx_data, dmx_data2
29    dmx_data2 = received_data
30    label1.setText(str((str("Channel 2:") + str(dmx_data2))))
31
32
33def setup():
34    global Title, label0, label1, dmx_0, dmx_data, dmx_data2
35
36    M5.begin()
37    Widgets.fillScreen(0x222222)
38    Title = Widgets.Title("DMX512Unit Rec example", 3, 0xFFFFFF, 0x0000FF, Widgets.FONTS.DejaVu18)
39    label0 = Widgets.Label("Channel 1:", 0, 57, 1.0, 0xFFFFFF, 0x222222, Widgets.FONTS.DejaVu18)
40    label1 = Widgets.Label("Channel 2:", 2, 109, 1.0, 0xFFFFFF, 0x222222, Widgets.FONTS.DejaVu18)
41
42    dmx_0 = DMX512Unit(1, port=(13, 14), mode=2)
43    dmx_0.attach_channel(1, dmx_0_channel1_receive_event)
44    dmx_0.attach_channel(2, dmx_0_channel2_receive_event)
45    dmx_0.receive_none_block()
46
47
48def loop():
49    global Title, label0, label1, dmx_0, dmx_data, dmx_data2
50    M5.update()
51
52
53if __name__ == "__main__":
54    try:
55        setup()
56        while True:
57            loop()
58    except (Exception, KeyboardInterrupt) as e:
59        try:
60            from utility import print_error_msg
61
62            print_error_msg(e)
63        except ImportError:
64            print("please update to latest firmware")

UIFLOW2 Master Example:

tx_example.png

UIFLOW2 Slave Example:

rx_example.png

dmx512_core2_send_example.m5f2

dmx512_core2_receive_example.m5f2

class DMX512Unit

Constructors

class DMX512Unit(id, port, mode=DMX_MASTER)

Initializes the DMX512 unit with a specified UART ID and port pins.

Parameters:

  • id (Literal[0,1,2]) – UART device ID(DMX port id).

  • port (list|tuple) – UART TX and RX pins.

  • mode (int) – Operating mode (1 for Master, 2 for Slave).

UIFLOW2:

init.png

Methods

DMX512Unit.dmx_init(mode) → None

Initializes the DMX512 communication with UART pins and mode.

Parameters:

mode – Operating mode (1 for Master, 2 for Slave).

UIFLOW2:

dmx_init.png

DMX512Unit.deinit() → None

Deinitializes the DMX512 unit and stops any ongoing operations.

UIFLOW2:

deinit.png

DMX512Unit.write_data(channel, data) → None

Updates the data for a specified DMX channel. Data is sent on the next update cycle.

Parameters:

  • channel – DMX channel number (1-512).

  • data – Data value to be sent (0-255). @raises ValueError if the channel number is out of range.

UIFLOW2:

write_data.png

DMX512Unit.clear_buffer() → None

Clears the DMX buffer and resets the data.

UIFLOW2:

clear_buffer.png

DMX512Unit.read_data(channel) → int

Reads data from a specified DMX channel in Slave mode.

Parameters:

channel – DMX channel number (1-512).

UIFLOW2:

read_data.png

DMX512.receive_none_block() → None

Starts non-blocking data reception for the specified channels with associated callbacks.

UIFLOW2:

receive_none_block.png

DMX512Unit.attach_channel(channel, callback) → None

Attaches a callback function to a specified DMX channel.

Parameters:

  • channel – DMX channel number (1-512) to attach the callback to.

  • callback – The function to be called when data changes on the specified channel.

UIFLOW2:

receive_data_event.png

DMX512.stop_receive() → None

Stops the non-blocking data reception task.

UIFLOW2:

stop_receive.png

DMX512Unit.detach_channel(channel) → None

Detaches the callback function from a specified DMX channel.

Parameters:

channel – DMX channel number (1-512) to detach the callback from.