DmxRdmLib for ESP8266

Initial version by Matthew Tong, June 2016. This library is derived from the HardwareSerial library.

Merged with the version with RDM (does not have its own git repo) which was used in the ESP8266_ArtNetNode_v2 project.

This library will transmit up to 2 DMX universes from an ESP8266 module. It utilizes the hardware UARTs and is entirely interrupt driven meaning the DMX output has very precise timing.

The DMX will refresh at a minimum rate of 44Hz. The library will detect how many channels have been set, outputting less than 512 if possible to increase the refresh rate. This increases the responsiveness of fixtures. It will still output a full 512 channels at least once per second.

LIMITATIONS

You cannot use dmxB as an input. Calling dmxB.dmxIn(true) will cause the library to hang and boot loop. I believe this is because of the hardware limitation that the ESP8266 essentially only has a single UART RX channel on UART0. The ESP8266EX datasheet does specify U1RXD but IO8/RX2 to which it is attached is normally used by the flash interface.

If you do enable dmxA as input, RDM is disabled as there is no RX channel for use.

USAGE

dmxA uses the same uart as Serial, dmxB uses the same uart as Serial1. If you wish to use a serial port, dont call the .begin() function of the relevant dmx port.

espDMX is driven entirely by the TX FIFO empty interupts. To ensure constant output and accurate timing, ensure that global interupts aren't stopped for too long.

Note: I will be using dmxN in place of dmxA or dmxB as the commands for each are identical.

Include the following code in setup. dirPin is the pin to output the signal for the direction pin of the RS485 driver. If you are direction pin is wired permanently do not use this parameter. Use the buffer parameter if you want to have your own dmx data storage location (not using the internal dmx data buffer of the library). If you want to use the internal buffer just don't use the parameter. Neither parameter is required.

  // No direction pin. Using library-internal buffer for dmx data.
  dmxN.begin();
  
  // Direction pin defined. Using library-internal buffer for dmx data.
  dmxN.begin(dirPin);
	
  // No direction pin. Using own dmx data buffer.
  dmxN.begin(myBuffer);
  
  // Direction pin defined. Using own dmx data buffer.
  dmxN.begin(dirPin, myBuffer);

For further information about using your own buffer take a look at the example "dmxOutput".

DMX Receive:

To make the port an Input Port:

  // set to input
  dmxN.dmxIn(true);
  
  // define callback function for dmx data (see example for further 
  dmxA.setInputCallback(dmxIn);

To get a pointer to the data buffer:

  dmxN.getChans();

If you used your own buffer (begin() with parameter buf) you can find the latest dmx data in the buffer you specified.

DMX Send:

data is a byte array up to 512 length, numChans is the number of channels you're setting, startChan is the channel number (1 - 512) of the first item in data.

  dmxN.setChans(data, numChans, startChan);
  
  // assume startChan = 1
  dmxN.setChans(data, numChans);
  
  // assume 512 channels starting at channel 1
  dmxN.setChans(data);

Note: No data will be sent until the first setChans() function is called. This is to ensure no "zero" data is sent on power up or reboot.

To clear the data buffer and reset all channels to zero:

  dmxN.clearChans();

General:

• Every port is an Output by default.

To change the transmission direction of a port, set isOutput to true for Input, false for Output:

  dmxN.dmxIn(isInput);

To stop DMX transmission, use the end() function. It will leave the DMX line in an idle (HIGH) state. You can also pause or unPause the output which only disables the interupts.

  dmxN.end();
  dmxN.pause();
  dmxN.unPause();

Currently inoperable:

To change the activity LED intensity, use the following:

  dmxN.ledIntensity(newIntensity);