# Preparing the Operating System for UPIWIN

The Raspberry Pi OS needs to be configured with the appropriate device tree support, software, and libraries to compile
and run UPIWIN successfully.  This document describes the process.

## Preparing the Operating System

1. Download an image of Raspberry Pi OS from
   [the Raspberry Pi Foundation](https://downloads.raspberrypi.org/raspios_armhf/images/). The most-recent version of
   Raspberry Pi OS that is known to work with the PiTFT is
   [the December 4, 2020 image](https://downloads.raspberrypi.org/raspios_armhf/images/raspios_armhf-2020-12-04/).
2. Unzip the `.zip` file for your image and write th included `.img` file to a fresh MicroSD card using one of the
   methods described on [this page](https://www.raspberrypi.org/documentation/computers/getting-started.html).
3. Connect your UPIWIN-compatible Raspberry Pi (RPi 3B+ with PiTFT) to power, HDMI display, keyboard, and network
   (if necessary).  Insert the freshly-written MicroSD card into the Pi.
4. Turn on the Pi, boot into Raspberry Pi OS, and set it up.  Make sure to get updates installed.

## Installing the PiTFT Drivers

1. In a terminal window, enter the command `sudo -i` to get a root command prompt.
2. Enter the following commands:

    pip3 install --upgrade adafruit-python-shell click
    git clone https://github.com/adafruit/Raspberry-Pi-Installer-Scripts.git
    cd Raspberry-Pi-Installer-Scripts
    python3 adafruit-pitft.py --display=28c --rotation=90

3. Answer "N" to the questions about the console appearing on the PiTFT display and mirroring HDMI to the PiTFT
   display.
4. Reboot the Pi when prompted.

## Installing Libraries for UPIWIN

1. Use `sudo -i` to get a root command prompt.
2. Execute the command to install packaged libraries and utilities:

    apt install python3-dev libfreetype6-dev libpng-dev libzip-dev ttf-mscorefonts-installer zip

3. Execute the commands to install the BCM2835 library:

    wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.68.tar.gz
    tar xzvf bcm2835-1.68.tar.gz
    cd bcm2835-1.68
    ./configure
    make
    make check
    make install

4. Copy the Arial font to where the code expects to see it:

    mkdir /usr/local/share/fonts/truetype
    cp /usr/share/fonts/truetype/msttcorefonts/arial.ttf /usr/local/share/fonts/truetype

## Building the Source

After cloning the repository for UPIWIN, enter the following commands:

    cd upiwin
    make

The resulting executable and demo scripts will be placed into the `output` directory.

To execute, change to the `output` directory and enter the command `sudo ./upiwin` followed by the name of the script
to be run. For example, `sudo ./upiwin demo1.py`.
