Pionic - PI-based Networked Instrument Controller

Physical configuration:

The network interface connects to the factory subnet and receives an
address via DHCP. The DHCP server is configured to assign a specific IP
address for the PI's MAC, presumably correlates to the test station ID.

A USB ethernet dongle attaches to the DUT and gets a static IP (defined in pionic.cfg).

The 40-pin I/O connector attaches to test instrumentation, which is customqqqqqqqqized for
the specific test station requires and not in scope of this document.

Pionic provides:

NAT translation from the DUT to the factory subnet. SSH to port 2222 on the
factory interface is forwarded to DUT port 22.

If enabled in pionic.cfg, the beacon server is started on the DUT
interface, this transmits "beacon ethernet packets. The DUT listens for
beacons during boot, if detected then it enters factory diagnostic mode and
brings up pre-defined static IP in the same subnet.

Alternatively if the DUT will automatically bring up static IP during
boot, it can simply attempt to access Pionic's CGI server, and if a
response is received then it enters diagnostic mode.

Access to test-specific CGI's on port 80, the DUT uses curl e.g.:

    curl -f http://172.31.255.1/gpio?14=1

To install:

Download the SDcard image:

    http://downloads.raspberrypi.org/raspbian_lite/images/raspbian_lite-2018-11-15/2018-11-13-raspbian-stretch-lite.zip,

Unzip and extract file 2018-11-13-raspbin-stretch-lite.img (about 1.8GB). 

Install the .img file to an 8GB SDcard using dd on linux or Win32DiskImager
on Windows.

Insert the card into the Pi, attach monitor and usb keyboard. It should
boot to a text console (if it boots to X, you have the wrong image). Log in
as user 'pi', password 'raspberry'

Run 'sudo raspi-config':

    Change User Password:

        Set user 'pi' password as desired

    Interfacing Options:

        SSH: Yes
        VNC: No
        I2C: Yes
        Serial: Yes

    Advanced Options:

        Memory split: 0

Attach ethernet, wait for IP to come up, then run:

    sudo apt update
    sudo apt upgrade
    sudo apt install git
    git clone https://github.com/glitchub/pionic
    make -C pionic

Make sure ethernet dongle is attached to USB and reboot.

Note Pionic takes over the display, will show green status screen if
started successfully, or red screen if not. Subsequent login must occur via
SSH or serial terminal.