UniPi 1.1/RasPi 3/7"Official RasPi Touchscreen
Can I combine all three of these together? It seems as though I can only get two of the three to work, ie RasPi and UniPi or RasPi and Touchscreen. Whenever I install the display ribbon cable from the touchscreen into the RasPi nothing will power on.
We don't officially support using the touchscreen with the UniPi 1.1. I would try it first without the UniPi 1.1 board. If it works that way you may have a conflict on the I2C port, which the touchscreen uses.
There is a number of topics regarding the touchscreen I2C address conflicts on the official forums, which may be of further help.