TS-7250-V3 DIO Header
From embeddedTS Manuals
The DIO header is a 0.1" pitch 2x8 header including SPI and GPIO. All pins on this header are 5V tolerant except SPI output pins. The SPI input pins are 5V tolerant and can be connected to a 5V SPI device. All of these DIO include pullups.
To use the SPI pins on this header as GPIO instead, disable SPI by changing the FPGA Syscon 0x08 bit 10:
tshwctl -a 0x8 --poke32 0x400
The DIO header is designed to provide compatibility with the KPAD accessory. This is a 4x4 numerical keypad. This is supported in userspace with the keypad.c source code, or the "keypad" utility which is included in the shiping image.
This debounces presses to 50ms, and does not repeat when numbers are held. This will output a string containing the key that is pressed. Eg:
root@tsimx6:~# keypad 1 UP DOWN 2ND ENTER