I've created a library to manage the non-I2C version of the TTP229 based 4x4 keypad.
It allows you to use callbacks to process keypad inputs, and will use either your board's built-in SPI hardware or any two digital pins (via bit bang i/o).
The initial version of the library can be found at: https://github.com/bratoff/TTP229_SPI
Please check it out and let me know if you find it useful. If there is enough interest I will submit it for inclusion in the library manager.