SBC Axel SBC/Interfaces and Connectors/Touchscreen
History | |||
---|---|---|---|
ID# | Issue Date | Notes | |
28/10/2020 | First DESK release |
Touchscreen[edit | edit source]
Description[edit | edit source]
The 4-wire resistive touch controller signals are routed to J50, which is a 4 pin (1mm pitch vertical) ZIF connector for the 4-wires resistive controller.
The touch controller is a TI TSC2003 device, connected to the I²C2 bus (address 0x1001000b).
Signals[edit | edit source]
The following table describes the interface signals:
Pin# | SOM Pin# | Pin name | Pin function | Pin Notes |
---|---|---|---|---|
1 | - | TSC_YP | Touch controller Y+ | |
2 | - | TSC_XP | Touch controller X+ | |
3 | - | TSC_YM | Touch controller Y- | |
4 | - | TSC_XM | Touch controller X- |
Device mapping[edit | edit source]
The device is typically mapped to /dev/touchscreen0
device in Linux.
The touch controller is attached to the generic Linux input event interface (evdev).
Device usage[edit | edit source]
The simplest tools for touch screen management are the tslib library and ts_tools utilities. To calibrate the touch screen, the ts_calibrate
command line tool is available.
After calibration, the touch screen can be tested using the graphical ts_test
utility or the ts_print
command line tool.