Hello Duhjoker
DC is data/command select as someone here already pointed out.
What you need to understand, is some basics of the SPI protocol. Its just not a simple question of "what pin does D/C go to?". You need to understand what each pin does. Once you understand what the pins mean, you can start to build any kind of console with any kind of SPI screen.
![Image](http://www.totalphase.com/support/article_attachments/200063846/spi-diagram.png)
This is how SPI works:
- there is a master
- there is one or more slaves
- notice, that there are only 4 pins going into each slave
This is what the pins do:
- SCLK is the clock line. Very important. It synchronises the Master and the Slaves to exchange information at the same speed.
- MOSI - Master Out, Slave In. Data from master to slave. This goes from master mosi to slave (lcd) SCR_DIN as you figured out
- MISO - data in the opposite direction
- SS - slave select. In order to tell WHICH slave is supposed to get the next command or data, the Master pulls this pin LOW to talk to each slave. Only one slave should be active at the same time. All other SS lines should be HIGH. SS is often also called CS (cable select) or EN (enable)
Now, you notice now that there is NO DC line in this picture.
How can it be ?
The DC or D/C is a feature, that is specific to the 5110 graphics driver chip. It has nothing to do with the SPI protocol. Therefore, the DC pin can be ANY NORMAL PIN you choose from the Master side. You choose what pin it is, by specifying it in the program code.
So you see, there is no one answer to your question. You need to look at the code and/or copy paste it here to find out what pin on the Master is the DC.