Overview

This implements a Wifi Artnet receiver to receive Artnet frames and send them out over DMX. The Idea is to fit the modules into DMX equipment and be able to use Wifi instead of DMX cabling.

The module uses WifiManager to connect to a Wifi network on initial startup. On subsequent boots, it will reconnect to the same network again with, no configuration necessary. The initial hostname is based on the hardware ID of the ESP8266. This name can be changed and saved.

The Artnet/DMX Universe can be configured, along with the max frame size and the update rate.

A WS2812 RGB LED is used to show the display status. The same status can be seen on the console output or the webinterface.

The colors displayed are as follows:

• Red: The device is booting
• Yellow: Connecting to Wifi
• Pink: Device is ready and conneted to Wifi
• Blue: Web-interface activity
• Cyan: Artnet frames are detected, but ignored as the universe does not match
• Green: Artnet frames are received and transmitted to DMX

Wherever there is activity on the web interface (configuration, monitoring), the LED turns blue. During web interface activity, the DMX512 output is silenced. A smooth web interface and smooth DMX signalling don't go together.

Special features

• The MAX485 transmitter is switched off, when no frames are sent. This places the driver in high-Z mode and allows to use the DMX input with the ESP_DMX device still connected.
• Everything is self-contained in the binary. There is no need to upload/maintain data in the SPIFFS filesystem. SPIFFS is still used to hold the configuration data and as temporary storage for updating the firmware.

Components

• Wemos D1 mini
• MAX485 module
• WS2812 RGB LED

Wiring diagram

     Wemos D1:
                        +-----+ 
                   Rst  +  W  +  Tx
                    A0  +  E  +  Rx
             D0/GPIO16  +  M  +  D1/GPIO5   -> RS422 En
    LED_B <- D5/GPIO14  +  O  +  D2/GPIO4 
    LED_R <- D6/GPIO12  +  S  +  D3/GPIO0*
NEO/LED_G <- D7/GPIO13  +     +  D4/GPIO2*  -> RS422 Tx
             D8/GPIO15* +  D  +  Gnd
                   3V3  +  1  +  5V
                        +-----+ 


        MAX485:		1 Rx      vcc 8
		            2 RxEn   outb 7
		            3 TxEn   outa 6
		            4 Tx      gnd 5

There is also a schematics among the files

ToDo

Add an Artnet PollReply so that the device is visible to Artnet controllers

Reference

The Sketch by Robert Oosterveld http://robertoostenveld.nl/art-net-to-dmx512-with-esp8266 has server with examples and some code.