DPI (Display parallel Interface)

Like VGA666, this pcb uses dpi interface (in mode 3 to free gpio 18 & 19)

see https://www.raspberrypi.org/documentation/hardware/raspberrypi/dpi/README.md

only the necessary bits of the dpi are redirected to the 40-pin GPIO port, with the vga565.dtbo file loaded at startup

here is the code of the file:

/dts-v1/;

/plugin/;

/{

        compatible = "brcm,bcm2708";

        // There is no VGA driver module, but we need a platform device

        // node (that doesn't already use pinctrl) to hang the pinctrl

        // reference on - leds will do

        fragment@0 {

                target = <&leds>;

                __overlay__ {

                         pinctrl-names = "default";

                         pinctrl-0 = <&vga565_pins>;

                };

   };

        fragment@1 {

                target = <&gpio>;

                __overlay__ {

                         vga565_pins: vga565_pins {

                        brcm,pins = <2 3 4 5 6 7 8 12 13 14 15 16 17 20 21 22 23 24>;

                                  brcm,function = <6>; /* alt2 */

                            brcm,pull = <0>; /* no pull */

                   };

           };

   };

};

/boot/config.txt

# disable i2c, pin use by h-sync & v-sync

dtparam=i2c_arm=off

dtoverlay=vga565

dpi_output_format=0x13

enable_dpi_lcd=1

display_default_lcd=1

dpi_group=2

dpi_mode=16

#---------------- dpi_mode line ---------------------

#---> 640x480 60hz   dpi_mode=4

#---> 800x600 60hz   dpi_mode=9

#---> 1024x768 60hz  dpi_mode=16

#---> 1280x768 60hz  dpi_mode=23

#---> 1280x800 60hz  dpi_mode=28

#---> 1280x960 60hz  dpi_mode=32

#---> 1280x1024 60hz dpi_mode=35

#---> 1360x768 60hz  dpi_mode=39

#---> 1366x768 60hz  dpi_mode=81

#---> 1400x1050 60hz dpi_mode=42

#---> 1440x900 60hz  dpi_mode=47

#---> 1600x1200 60hz dpi_mode=51

#---> 1680x1050 60hz dpi_mode=58

#---> 1920x1080 60hz dpi_mode=82

#---> 1920x1200 60hz dpi_mode=69

#---> 1920x1440 60hz dpi_mode=73

alternate config, no need dtbo file

# disable i2c, pin use by h-sync & v-sync

dtparam=i2c_arm=off

gpio=2-8,12-17,20-24=a2

dpi_output_format=0x13

enable_dpi_lcd=1

display_default_lcd=1

dpi_group=2

dpi_mode=16

#---------------- dpi_mode line ---------------------

#---> 640x480 60hz   dpi_mode=4

#---> 800x600 60hz   dpi_mode=9

#---> 1024x768 60hz  dpi_mode=16

#---> 1280x768 60hz  dpi_mode=23

#---> 1280x800 60hz  dpi_mode=28

#---> 1280x960 60hz  dpi_mode=32

#---> 1280x1024 60hz dpi_mode=35

#---> 1360x768 60hz   dpi_mode=39

#---> 1366x768 60hz  dpi_mode=81

#---> 1400x1050 60hz dpi_mode=42

#---> 1440x900 60hz  dpi_mode=47

#---> 1600x1200 60hz dpi_mode=51

#---> 1680x1050 60hz dpi_mode=58

#---> 1920x1080 60hz dpi_mode=82

#---> 1920x1200 60hz dpi_mode=69

#---> 1920x1440 60hz dpi_mode=73

Dual Screen (VGA + HDMI)

 need raspbian buster

edit file /boot/config.txt

at the end of the file, add line:

[all]

#dtoverlay=vc4-fkms-v3d

max_framebuffers=2

edit file /usr/share/X11/xorg.conf.d/99-fbturbo.conf

 This is a minimal sample config file, which can be copied to

# /etc/X11/xorg.conf in order to make the Xorg server pick up

# and load xf86-video-fbturbo driver installed in the system.   

#

# When troubleshooting, check /var/log/Xorg.0.log for the debugging

# output and error messages.

#

# Run "man fbturbo" to get additional information about the extra

# configuration options for tuning the driver.

#Section "Device"

#       Identifier     "Allwinner A10/A13 FBDEV"

#       Driver         "fbturbo"

#       Option         "fbdev" "/dev/fb0"

#       Option         "SwapbuffersWait" "true"

#EndSection

Section "Device"

Identifier "Raspberry Pi HDMI"

Driver "fbturbo"

Option "fbdev" "/dev/fb0"

Option "ShadowFB" "off"

EndSection

Section "Device"

Identifier "Raspberry Pi DPI"

Driver "fbturbo"

Option "fbdev" "/dev/fb1"

Option "ShadowFB" "off"

EndSection

Section "Monitor"

Identifier "HDMI"

EndSection

Section "Monitor"

Identifier "DPI"

EndSection

Section "Screen"

Identifier "screen0"

Device "Raspberry Pi HDMI"

Monitor "HDMI"

EndSection

Section "Screen"

Identifier "screen1"

Device "Raspberry Pi DPI"

Monitor "DPI"

EndSection

Section "ServerLayout"

Identifier "default"

Screen 0 "screen0" 0 0

Screen 1 "screen1" RightOf "screen0"

Option "Xinerama" "on"

EndSection

Remote Desktop MultiMonitor

install freeRDP

sudo apt-get install freerdp2-x11

start freeRDP session

xfreerdp /v:<computer name or IP> /u:<user> /d:<domain> /sound:sys:alsa /multimon

or

xfreerdp /v:<computer name or IP> /u:<user> /d:<domain> /g:<gateway name or IP> /gu:<gateway user> /gd:<gateway domain> /sound:sys:alsa /multimon

Audio Interface

audio interface is connected to gpio 18 & 19 (PWM)

see https://learn.adafruit.com/adding-basic-audio-ouput-to-raspberry-pi-zero/pi-zero-pwm-audio

/boot/config.txt

# Enable audio for PiZero(loads snd_bcm2835)

dtoverlay=pwm-2chan,pin=18,func=2,pin2=19,func2=2

dtparam=audio=on

SPI Interface

GPIO 9 , 10, 11 , 25, 26, 27 can be used as SPI , whit overlay spi0-cs, with CS redirection to gpio 26 & 27

/boot/config.txt

# uncomment to use spi0 with cs0 & cs1 retirected on pin 26 & 27

dtparam=spi=on

dtoverlay=spi0-cs,cs0_pin=26,cs1_pin=27

Installation

Copy vga565.dtbo to /boot/overlays/ and copy content of config-example.txt to /boot/config.txt

Révision

rev1

bad vga footprint, hole too small

rev2

change vga footprint

move j3 & j5

rev3

add GPIO25 to J4 connector

add j6 DC 3.5x1.3 connector