View source for Orange pi DMX 4x

== Introduction ==
The Orange Pi DMX 4x board allows you to interface an Orange pi with DMX hardware.  

(the Orange pi one I believe. Let me know if you know for sure, or if you've tried other boards) 

The CPU on the orange pi has four UARTs so the board supports 4 DMX channels. In theory they can all support DMX out, RDM and DMX in, but in practice, software support for IN is limited. 

== Software ==

You can probably run OLA and QLC+ with this card. Currently untested. Let me know if you try it. 

The board was designed in cooperation with Arjan van Vught. His suite completely supports this board. 

== Hardware == 

Also known as "what's what". 

=== gpio ===
First there is the main 40-pin GPIO connector. It should mate with the GPIO connector of your SBC. Please keep an eye on the orientation  of the connector. On our board the silkscreen signifies pin 1 with the one corner that is SQUARE, all other three are chamfered. 

On the orange pi this should make the board align mostly with the orange pi. If you have another SBC, you're welcome to try, but for example the raspberry pi has that GPIO connector precisely reversed compared to the orange pi. Thus the board will stick out from the pi. The raspberry pi has only one UART (on the GPIO connector), so it is guaranteed that you'll get only one channel to work. 

=== power: Screw ===

There is a power connector with screw terminals. 

If you look the connector "in the eye", the left one is the +5V, the other one is GND. 

=== power: USB ===

There is an USB connector that would allow you to power the board with underlying pi. Currently: No warranty on this: If it works, it works, if it doesn't it doesn't. Sorry. Plenty of other power options. 

=== I2C ===

The I2C bus is exported on this four-pin connector. This bus is not levelshifted as on some of our other boards. 3.3V devices only. 

Pinout: GND-SDA-SCL-5V

=== UART4 ===

The GPIO header on the orange pi only has 3 out of the four UARTs. The fourth is labeled "debug UART" and a three pin connector as well. You should've gotten a 3-pin cable to connect the two. 

pinout: GND RX TX. 

=== jumper blocks ===

Each of the channels has a jumper block. 

1-2 enables a pullup of one of the data lines. 
3-4 enables termination of the data lines
5-6 enables a pulldown of the other data line. 

Some people report bad results when you enable the pullup/pulldown. So be aware.