Santa Claus has brought me a 7″ touchscreen display for my raspberry pi.  I thought setting it up would be as easy as plug and play, and it probably is so for the new version 3 model B but for older versions you need some extra steps:

1. Identify which version of raspberry pi you have
2. You will need to get a microusb power source of at least 2A (I got one for €10) the power source which came with my raspi was only 1.2A and could not power the whole thing.
3. Do not power the raspberry pi via microusb. Power the display motherboard via microusb and power the raspberry board via GPIO 5v pin
4. Connect the SCL/SDA, 5V and GND pins from your display to the corresponding pins in the raspi’s GPIO
5. Connect the DSI bus
6. Boot your raspi and edit file /boot/config.txt adding a line at the end ignore_lcd=0 (to flip the screen also add lcd_rotate=2)
7. Start up your raspi and your display should be working