View source for Pi2jamma hardware and software info

[[Category:Unix]]
[[Category:Video Games]]

==Info==
[[File:Pi2jamma.jpg|400px|right]]

I recently picked up a [http://arcadeforge.net/Pi2Jamma-Pi2SCART/Pi2Jamma::248.html pi2jamma], which is a JAMMA compatible arcade board made to interface with a [https://www.raspberrypi.org/products/raspberry-pi-3-model-b/ Raspberry PI 3]. This is in use as an alternate JAMMA board in my [[Neo Geo Arcade Cabinet]].

The other comparable device to this is the [https://www.aussiearcade.com/forumdisplay.php/238-RaspberryJAMMA RaspberryJAMMA] / [https://arpicade.com/ Arpicade]. This uses the HDMI video output and converts to VGA.


==Hardware==
The pi2jamma was created by [http://www.zurborg.info/ Jochen Zurborg]. Its design is fairly simple, you simply mount the Pi3 on its GPIO pins and connect the audio from the headaphone jack out of the Pi in to the pi2jamma. Power is provided over GPIO, no additional connections are required outside of your JAMMA harness. 

it contains these primary components:

* Integrated [https://github.com/fenlogic/vga666 VGA 666] adapter circuitry which uses [https://github.com/fenlogic/vga666/blob/master/documents/vga_manual.pdf GPIO pins 4 - 21]  and requires at least a Pi3.

* [http://www.ti.com/lit/ds/symlink/ths7314.pdf THS7314] video amp

* [http://www.ti.com/lit/ds/symlink/lm380.pdf LM380N] 2.5w audio amp. Audio is fed  from 3.5mm input jack

* 3  [http://www.ti.com/lit/ds/symlink/sn54ls165a-sp.pdf 74LS165 shift registers] to allow for a total of 24 inputs over the few remaining GPIO pins (todo: which GPIO pins exactly?). This method is used because there are [http://www.ukvac.com/forum/dino-king-lcd-mount_topic357586_post994714.html#994714 very few remaining GPIO pins to use].  Other JAMMA/Pi solutions that use the pi's build in HDMI port tend to use [https://github.com/recalbox/mk_arcade_joystick_rpi mk_arcade_joystick_pi].
[[File:Pi2jamma-bottom.jpg|400px|right]]

==Software==
[http://strike-devices.net/index.php/pi2jamma/regamebox-distribution-for-pi2jamma/ Regamebox] is the official software distribution. [http://strike-devices.net/index.php/pi2jamma/retropie-for-pi2jamma/ Work has been done to make Retropie] work as well.

I have been working on porting the Arpicade software (intended for RaspberryJAMMA) which is just changing a few modules and script settings. 

Perform these steps with the SD card mounted in your system. Note that all of these paths are relative to the root of where your SD card is mounted:

* modify '''/boot/config.txt''' to load VGA666 drviers. This will have a lot of defaults in it, this is the full output of my file after some modifications (todo: finalize settings that I'm happy with):
 ##############################
 #this group is from arpicade
 disable_splash=1
 disable_overscan=1
 #overscan_scale=1
 #overscan_left=33
 #overscan_right=32
 gpu_mem=256
 
 ##############################
 #this group is from regamebox
 #gpu_mem=64
 disable_audio_dither=1
 dtparam=audio=on
 dtoverlay=vga666
 enable_dpi_lcd=1
 display_default_lcd=1
 dpi_group=2
 dpi_mode=87
 hdmi_timings=320 1 16 30 34 240 1 2 3 22 0 0 0 60 0 6400000 1 #240p


* Disable the mk_arcade_controls GPIO driver by commenting out the contents of '''/etc/modprobe.d/mk_arcade_joystick.conf'''. The pi will not boot with this and the vga666 drivers loading.
 #options mk_arcade_joystick_rpi map=1,2


First give yourself access to the pi over ssh since you won't initially have functioning video. With the SD card mounted to your PC, create a blank file caled  '''/boot/ssh'''. Enable wifi driver by commenting the contents of '''/etc/modprobe.d/raspi-blacklist.conf''', and put your SSID/psk combo into '''/etc/wpa_supplicant/wpa_supplicant.conf''':

Comment out these two lines in '''/etc/modprobe.d/raspi-blacklist.conf''' to enable wifi modules:
 #blacklist brcmfmac
 #blacklist brcmutil


Use the '''wpa-passphrase''' command from your machine. My PC is linux so it works, sorry I have no idea how to do this on Windows.  `'''wpa_passphrase yourssid hunter22'''` will spit out this text, which you place at the end of '''/etc/wpa_supplicant/wpa_supplicant.conf''':
 network={
 	ssid="yourssid"
 	#psk="hunter22"
 	psk=8a06b4578aa024328c74a94a217fa430b24fdb2d7c6796ce9bae8ff69ed91102
 }


At this point you should have a pi that boots and displays video, see if that is indeed the case. If so, Let's do the remaining steps via SSH. Default auth is the same as Raspbian - username: pi, password raspberry. You could su to root and set its password too, I did so and set it as '''arpicade'''. All of the remaining steps require you to be root or use sudo.

* Tell the pi to use the analog output for audio instead of HDMI. One can run '''raspi-config''' -> '''Advanced'''-> '''Audio''' or this command at a prompt:
 amixer cset numid=3 1


* Copy the '''pikeyd165''' binary and '''pikeyd165.conf'''  to Arpicade. The conf file must go in /etc/ but the binary can go wherever you'd like. I created a subdir in /etc/ and just tossed them both there:
 mkdir /etc/regamebox/
 ln -s /etc/regamebox/pikeyd165.conf /etc/pikeyd165.conf

It should look something like this:
  root@raspberrypi:/etc# ls -alh /etc/pikeyd165.conf 
  lrwxrwxrwx 1 root root 29 Dec 29 17:26 /etc/pikeyd165.conf -> /etc/regamebox/pikeyd165.conf
  
 root@raspberrypi:/etc# ls -alh /etc/regamebox/
 -rwxr-xr-x  1 root root  35K Dec 29 17:25 pikeyd165
 -rw-r--r--  1 root root 1.4K Dec 30 10:46 pikeyd165.conf


* Tell '''pikeyd165''' to start at boot by creating/updating a service. Create the file '''/etc/init.d/pikeyd165''' with these contents:
 #!/bin/sh
 ### BEGIN INIT INFO
 # Provides:          pikeyd165
 # Required-Start:	$local_fs
 # Required-Stop:	$local_fs
 # Should-Start:
 # Default-Start:     2 3 4 5
 # Default-Stop:
 # Short-Description: rpi GPIO keyboard controller
 # Description:       Originates from regamebox
 ### END INIT INFO
 
 PATH=/sbin:/usr/sbin:/bin:/usr/bin
 . /lib/init/vars.sh
 
 do_start () {
 	/etc/regamebox/pikeyd165 -smi -ndb -d
 }
 
 case "$1" in
   start|"")
 	do_start
 	;;
   restart|reload|force-reload)
 	echo "Error: argument '$1' not supported" >&2
 	exit 3
 	;;
   stop)
 	killall pikeyd165
 	;;
   *)
 	echo "Usage: motd [start|stop|status]" >&2
 	exit 3
 	;;
 esac
 :


* Tell debian to start the service upon boot:
 update-rc.d pikeyd165 defaults
 update-rc.d pikeyd165 enable


* Modify '''pikeyd165.conf''' for any required button mappings. By default it is coded to work with MAME's defaults, but may not have buttons mapped to escape out of a game back to your frontend. At bare minimum I've uncommented the 'quit emulator/game' section which maps to 1p start (10) + 1p button 1 (17):
 KEY_ESC        17 10
 # todo: fix p2 coin mapping


At this point you should have a functional Arpicade image on pi2jamma. Note that all of these things should work equally on a fresh [https://www.raspberrypi.org/downloads/raspbian/ Raspbian] install as well, you'll just have to do extra work to get a frontend to work. Arpicade uses the [http://attractmode.org/ Attract Mode frontend] by default.

Other optional tweaks I made were:
* tell Attract Mode to [http://forum.attractmode.org/index.php?topic=1324.0 always stay 240p] (not 480i) after leaving a game by modifying the end of each file in /boot/launchers/*.sh and commenting this section out at the very bottom:
 #tvservice -e "CEA 6 HDMI" & sleep 3
 #fbset -depth 8
 #fbset -g 720 480 720 480 16