Setting up the display

First you need to wire up the display as following:

When you have wired the display you have to boot your Raspberry pi and run:

sudo raspi-config

To make the module load on boot-up run this

sudo REPO_URI=https://github.com/notro/rpi-firmware rpi-update
sudo nano /etc/modules
fbtft_device name=sainsmart18 rotate=90

Source: http://www.raspberrypirobot.com/1-8-tft-lcd-display-raspberry-pi-expansion-board/

sudo reboot

Now you have to reboot and the display should work. In the beginning the display would be blank but after a while you should see the terminal. Now you could login with the default credentials.

To start the desktop environment you have to run

sudo FRAMEBUFFER=/dev/fb1 startx -- -dpi 60

Installing RetroPie

Installing RetroPie is very simple. You just have to follow the steps on the github page and make it boot automatically.

https://github.com/retropie/RetroPie-Setup

Before we install the program to run RetroPie on the display it would be easier to configure it on a monitor because the text is very small on the display. But if you want to configure it on the TFT you could do step 6 first.

I configured the controls as following:

Routing EmulationStation to the TFT

The emulators won't route to the TFT by default. That's why we have to install fbcp.

Fbcp is used to mirror /dev/fb0 to /dev/fb1. To install it you have to do the following:

sudo apt-get install cmake
git clone https://github.com/tasanakorn/rpi-fbcp
cd rpi-fbcp/
mkdir build
cd build/
cmake ..
make
sudo install fbcp /usr/local/bin/fbcp

Then you need to edit /boot/config.txt and add or change the existing lines to:

hdmi_force_hotplug=1
hdmi_cvt=160 128 60 1 0 0 0
hdmi_group=2
hdmi_mode=87
  
dtoverlay=pitft28r,rotate=90,speed=80000000,fps=60

Setting up Adafruit-Retrogame:

Clone Adafruit-Retrogame from the github repo

git clone https://github.com/adafruit/Adafruit-Retrogame.git

this is done cd into Adafruit-Retrogame and open retrogame.c inside the

Adafruit-Retrogame folder. In retrogame.c you should search for the

line "ioStandard[] = {" and change it to the following:

ioStandard[] = {
        // This pin/key table is used when the PiTFT isn't found
        // (using HDMI or composite instead), as with our original
        // retro gaming guide.
        // Input   Output (from /usr/include/linux/input.h)
        {   5,     KEY_LEFT     },
        {   6,     KEY_RIGHT    },
        {  13,     KEY_UP       },
        {  19,     KEY_DOWN     },
        {  20,     KEY_Z        },
        {  16,     KEY_X        },
        {  26,     KEY_KP7      },
        {  21,     KEY_KP8      },
        {  12,     KEY_5        },
        {  23,     KEY_6        },
        {  -1,     -1           } }; // END OF LIST, DO NOT CHANGE

make retrogame

Because RetroPie is build on SDL2 it won't recognize the input by default that's why we need to add a rule. To add the rule you have to open /etc/udev/rules.d/10-retrogame.rules and add the following line:

SUBSYSTEM=="input", ATTRS{name}=="retrogame", ENV{ID_INPUT_KEYBOARD}="1"

After you have added the rule we can make retrogame run on boot by editing rc.local. The location of this file is /etc/rc.local in these file you have to append

/home/pi/Adafruit-Retrogame/retrogame &

before the "exit 0" line.