Default EYESPI Pins

• MO - This is the SPI MOSI (Microcontroller Out / Serial In) pin. It is used to send data from the microcontroller to the SD card and/or display. It is connected to the default MOSI pin on the QT Py.
• MI - This is the SPI MISO (Microcontroller In / Serial Out) pin. It's used for the SD card. It isn't used for the display because it's write-only. It is connected to the default MISO pin on the QT Py.
• SCK - This is the SPI clock input pin. It is connected to the default SCK pin on the QT Py.
• TFT CS - located on the TX pin. This is the TFT or eInk SPI chip select pin.
• TFT DC - located on the RX pin. This is the display SPI data/command selector pin.

The following pins are optional depending on the display you are using:

• IRQ - the Interrupt pin, located on the A0 pin. Many of our displays don't use the IRQ pin unless there's a touchscreen. When a touch is detected, this pin goes low. 
• Touch CS - located on the A1 pin. Many of our displays don't have a touchscreen.
• Memory CS - located on the A2 pin. Only our E-Ink displays have a separate memory SRAM chip, which you may be able to skip using on most QT Py's.
• SD Card CS - located on the A3 pin. This pin is required for communicating with the onboard display SD card holder.

I2C Logic Pins

The I2C pins are connected to the I2C port on the QT Py headers - some boards have a separate QT Py I2C port so keep in mind they may be separate busses.

• SCL - This is the I2C serial clock pin. 
• SDA - This is the I2C serial data pin. 

Extra EYESPI Pins

• LIT/LITE - the Backlight Control pin. By default, this pin is not connected to any of the QT Py pins. It is default on for most of our displays and is unused on E-Ink.
• RST/RESET - the Display Reset pin. By default, this pin is not connected to any of the QT Py pins. It is default on for most of our displays. Sometimes its used for low-power on E-Ink.

Through-Hole Solder Pads and Jumpers

There are jumpers and through-hole solder pads for some of the EYESPI pins to enable you to change the default QT Py pins.

First, cut the trace on the jumper associated with the default pin. Next, solder a wire between the solder pad and the desired QT Py pin.

• TCS/TS CS - the Touch CS pin
• MCS/MEMCS - the Memory CS pin
• SCS/SD CS - the SD Card CS pin
• INT - the IRQ/Interrupt pin
• DC - the TFT DC pin
• CS - the TFT CS pin