ARVID - homebrew arcade videocard

version 0.4f

Arvid is an open source and open hardware videocard with the main goal to produce perfect TV output for arcade games of the past emulated on modern PCs.

more info about the project: http://www.volny.cz/molej/arvid

dependencies: am335x_pru_package software from: https://github.com/beagleboard/am335x_pru_package Make sure you can access its header files and libprussdrv.a library. If you have a BBG with kernel 3.8.13 or so, chances are you will need no downloads or installation at all as required libraries and tools are already installed. As of 2016 it doesn't work on 4.X Linux kernel, so use 3.8.X kernel which supports PRU.

build:

• build works only on BBG (BBB) mini computer
• to build all just type 'make'

notes:

• libarvid requires superuser access to access PRU and gpios
• libarvid manages setting up cape manager itself
• libarvid manages ddr mapping itself
• works on BBB and BBG but not on older HW as it depends on exact PRU timing (older hardware PRU clock is slower)
• pru binary code (prustream.bin, pruvideo_XXX.bin) have to exist in current working directory of an application that uses/links libarvid

Ver 0.4f

• Added reading of more GPIO buttons. This now covers 2 player buttons up to 4 buttons each, 4 directions and Start and Coin. Compatibility with the previous version of software is preserved.
• Modified DTBO to claim extra GPIOs required for reading buttons.
• Added new test app for checking the state of buttons.
• Modified video mode height of the service screen. Now the height is 224 lines to better adhere to NTSC standard at 60Hz
• Added power-off command to arvid server. This allows arvid client to remotely poweroff the BBG. It forces arvid to close and exits the server with return code 50. The 'poweroff' command itself has to be issued in a shell script invoking the arvid-server.

Ver 0.4e

• Added virtual vsync option that allows to minimize screen latencies. New function was added : arvid_set_virtual_vsync(int vsync_line) where vsync_line is the scan line that triggers the vsync event. By default the feature is disabled (vsync_line = -1). If enabled arvid_wait_for_vsync() function will wait until the vsync_line is rendered on the screen and then it returns to the caller. If disabled arvid_wait_for_vsync() waits until the last line is rendered on screen and then it returns to the caller.

Ver 0.4d

• Added new mid-res video modes 416, 448, 512, 640

• Added automatic screen saver. After 3 minutes of inactivity the screen saver is started. To cancel it either a Coin or Start button has to be pressed or arvid API function has to be called. For example when an emulator is started the screen server is cancelled. This feature prevents screen burn when Arvid is idling in service screen or when an emulator / app crashed while unattended (inside arcade cab).

Ver 0.4c

• Picture quality enhancement. A timing bug was fixed so now the video signal is more stable. Previously every 8-th line was slightly shifted to the right causing artefacts.

• Support for firmware upgrade over network. The server can receive an upgrade file and store it locally. Physical unpacking of the upgrade file and replacement of arvid binaries is performed by the Linux OS scripts during Arvid reboot. NOTE! The Coin button MUST be pressed when the firmware is about to be uploaded. If the coin button is not pressed the uploaded file is rejected. It is for the security of your network to prevent malicious code to be uploaded to your BBG.

Ver 0.4b

• added new function to set screen X offset. This allows you to adjust the screen left position so it better fits your TV set. Use the following functions: arvid_set_line_pos() and arvid_get_line_pos() Valid values are 1 - 111 inclusive, where the default value is 60 (which roughly corresponds to the previous screen X position). All video modes are affected by this modifier the same way, that is all videomodes will be rendered at exactly the same X position irrespective of their resolution.

Ver 0.4a

• internal: simplified and unified videomode source code. It should be easier to define new videomode by just setting video parameters.
• added new videomode 336
• added videomode enumeration function
• added videomode test app

• arvid-server now shows the version number on the service screen

  Ver 0.3e

• added support for Start button on pin P9_25. When connected to ground arvid_get_button_state() will report the Start button is pressed. Make sure to copy the latest *.dtbo to /lib/firmware!

• removed the old 12-bit dts files (these were obsolete long time ago)

  Ver 0.3d

• new video mode 292
• fixed framerate test

Ver 0.3c

• changed the frame buffer streaming from PRU based to CPU based. The reason was to achieve better picture stability. Previously very slight screen horizontal shaking was present, which was caused by PRU jitter when it copied DDR memory. CPU based mem copy doesn't cause jitter, but increases the CPU load significantly.
• remove 'wicd' as it causes screen flickering now and then sudo apt-get purge wicd*

• identify running services by using: systemctl list-units --type service

  Ver 0.3b

• changed sync pin to p8.28 to fix startup issues
• added reading of buttons on GPIO3 (requires dtbo update) new buttons:
  • tate switch p9.27
  • coin button p9.28 all buttons need to be connected to ground to report value 1. Internally they are pulled high.
• dtbo now supports Beaglebone Green as well
• added arvid-splash program that shows arvid logo during boot-up
• improved arvid-server to show ipaddress of active network interface. Previously ipaddress of eth0 was always displayed even when it was not connected.
• improved service screen to show rotated logo according the state of the Tate switch.

Ver 0.3a

• now switched to 15bit graphics (previously 12 bit)
• new video modes 240, 392, 400
• requires gpio rewiring and new dtbo!

Ver 0.2c

• support for packet duplicates to tackle lost packets issue