There is a board named tk1exp. Designed by "http://dcac.taobao.com". It expanded all the available on the expansion header. Including MIPI CSI2, LCD interface, SPI（touch screen),I2C,GPIO,UART and so on.
Author's email: firstname.lastname@example.org
- A Touch screen interface. 4-wires or 5-wires resistive touch screen connector.
|1||X+for 4-wires touch screen, UL for 5-wires touch screen|
|2||X- for 4-wires touch screen, LL for 5-wires touch screen|
|3||COMMON for 5-wires touch screen|
|4||Y- for 4-wires touch screen, LR for 5-wires touch screen|
|5||Y+ for 4-wires touch screen, UR for 5-wires touch screen|
- B LCD interface.support eDP LCD by default, replace the coupling capacitor with 0ohm resistor and other resistor to support LVDS LCD
- C additional LCD brightness power connector.
- D BR_UART1( RS-232 level) connector
- E 4-wires UART2 RS-232 level connector
- F AD input(from touch controler)
- G Raspberry PI camera 1
- H Vmux
- I Raspberry PI camera 2
- J GPIO_PU0~PU6 3.3V or 5V level Set logic level by Q and R
- K I2C 3.3V or 5V level Set logic level by S
- L BR_UART1 3.3V or 5V level Set logic level by T
- N TS_SPI 3.3V or 5V level Set logic level by V
- O Camera 1 CSI-2 Only clk，lan0 and lan1，lan2 and lan3 on the P
- P Camera 2 CSI-2
- Q,R,S,T,V IOlogic level jumper，In the Figure 1，jumper to left for 5V，and right for 3.3V
- U UART2 3.3V or 5V level
- W Reset， power key，HSIC etc.