gpio

It’s possible to to add GPIOs to your computer, (openWRT) router, or Android tablet using some FTDI USB dongles that expose I/Os. On operating systems based on Linux, including Android, you can use the GPIO sysfs interface (/sys/class/gpio) to easily control GPIOs from the command line, and in some cases Rx, Tx, CTS, .. pins can also be used as GPIOs. Zoobab has tried it with various FTDI USB adapters, and Oneping OP-1010 breakout board based on PL2303 HDX chip, and the results are mixed, but it could worth a try. There are currently patchsets ([1] and [2]) awaiting acceptance to mainline kernel that will enable GPIO support for these USB devices, but in the meantime you need to patch the kernel yourself, and then enable the relevant options in the kernel config for example “USB_SERIAL_PL2303_GPIO” or “USB_SERIAL_FTDI_SIO_GPIO”. The first patch is for PL2303 chips, and the second for FT2xxx/FT4xxx […]