CM3-Panel-7-poe technical documentation

Make a Raspberry Pi OS microSD for CM3-PANEL-7-POE

This article explains how to create a standard Raspbian Pi OS MicroSD to use on the CM3-PANEL 7 POE starting from an official Raspberry Pi MicroSD image

Step-by-step guide

Download the image of standard Raspberry OS Version 2020-12-02 from these links:

Flash a microSD SD using Balena Etcher software.

Mount the microSD just created on your PC (Linux or Windows) or your Mac. The first microSD partition labeled "boot" is formatted as FAT32 and visible on any system. These files are to edit using an ASCII editor:

Edit cmdline.txt

Change:

console=serial0,115200

in:

console=serial1,115200

Edit config.txt

Change the content of config.txt file in:

# For more options and information see
# http://rpf.io/configtxt
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
#disable_overscan=1

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
#overscan_left=16
#overscan_right=16
#overscan_top=16
#overscan_bottom=16

# uncomment to force a console size. By default it will be display's size minus
# overscan.
#framebuffer_width=1280
#framebuffer_height=720

# uncomment if hdmi display is not detected and composite is being output
#hdmi_force_hotplug=1

# uncomment to force a specific HDMI mode (this will force VGA)
#hdmi_group=1
#hdmi_mode=1

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
#hdmi_drive=2

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
#config_hdmi_boost=4

# uncomment for composite PAL
#sdtv_mode=2

#uncomment to overclock the arm. 700 MHz is the default.
#arm_freq=800

# Uncomment some or all of these to enable the optional hardware interfaces
dtparam=i2c_arm=on
#dtparam=i2s=on
#dtparam=spi=on

# Uncomment this to enable infrared communication.
#dtoverlay=gpio-ir,gpio_pin=17
#dtoverlay=gpio-ir-tx,gpio_pin=18

# Additional overlays and parameters are documented /boot/overlays/README

# Enable audio (loads snd_bcm2835)
#dtparam=audio=on

[pi4]
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
#dtoverlay=vc4-fkms-v3d
#max_framebuffers=2

[all]
#dtoverlay=vc4-fkms-v3d

# -------------------------
# ACME Systems
# -------------------------
dtoverlay=goodix-7-acme
dtoverlay=disable-wifi
dtoverlay=disable-bt

#Ignore the HDMI cable hotplug (to avoid the delay at startup)
hdmi_ignore_hotplug=1

dtoverlay=pi3-disable-bt
enable_uart=1
dtparam=uart1=on
dtoverlay=uart1,txd1_pin=32,rxd1_pin=33

# Configure the uart0 on the console port hardware 
# This port is managed by the SOC using the miniUART and located on Linux on /dev/ttyS0
force_turbo=1
dtoverlay=uart0,txd0_pin=36,rxd0_pin=37,pin_func=6

# Activates the I2C 1 port on GPIO44 and 45 to talk with the
# touch screen controller end camera crypto-chip
dtparam=i2c_arm=on
dtparam=i2c=on
dtparam=i2c_arm_baudrate=100000

dtoverlay=i2c1,pins_44_45
dtoverlay=i2c1-rtc,pcf8523

## Enable the DPI port to talk with the TFT display
dtoverlay=dpi18
overscan_left=0
overscan_right=0
overscan_top=0
overscan_bottom=0
framebuffer_width=800
framebuffer_height=480
enable_dpi_lcd=1
display_default_lcd=1
dpi_group=2
dpi_mode=87
dpi_output_format=0x6f005
hdmi_timings=800 0 40 48 88 480 0 13 3 32 0 0 0 60 0 32000000 6

start_x=1
gpu_mem=128

# Enable second I2C Bus 3
dtoverlay=i2c-gpio,bus=3,i2c_gpio_delay_us=1,i2c_gpio_sda=35,i2c_gpio_scl=27

# Set the pull up (input) pins 27 and 35
gpio=27,35=pu

dtparam=audio=off
dtoverlay=i2s-gpio28-31
dtoverlay=hifiberry-dacplus

Download and save some binaries

In the first partition of the microSD save these binary files:

/overlays

/

Insert the microSD inside the CM3-Panel-7-poe microSD socket

Remove the Supercap jumper

Close JUMP PROG BYPASS and power up the CM3-Panel-7-poe

Links

CM3-Panel-7-poe technical documentation