Pi4 dashcam install

An abbreviated guide to configuring the Pi4 as a two camera dashcam

Download the latest version of Raspbian and unzip
 https://downloads.raspberrypi.org/raspbian_lite_latest

Install the image to a MicroSD card. For examples see: https://elinux.org/RPi_Easy_SD_Card_Setup

When the image is installed and if you can mount the boot partition, create an empty file called ssh in it, then place the SD card in your Pi, this will enable SSH by default. Otherwise place the card in your Pi4 and connect a monitor and a keyboard.

Login as the user 'pi' with the password 'raspberry'.

- Start the initial configuration by running raspi-config.
pi@raspberrypi ~ $ sudo raspi-config
1. Change password
2. Change hostname, setup wifi if desired
4. Change timezone
5. Enable camera and SSH (if needed)
7. Memory split can be set to the max of 512
<Finish>
(you can use the arrow keys, tab, ESC & Return to navigate)

When you are finished with the configuration reboot the Pi.

- Login back in and update the Rasbian packages
pi@rasp-pi4-dash ~ $ sudo apt-get update
pi@rasp-pi4-dash ~ $ sudo apt-get upgrade

- Install the excellent picamera software
pi@rasp-pi4-dash ~ $ sudo apt-get install python3-picamera

- Add the 'camera' user and give it a password.
pi@rasp-pi4-dash ~ $ sudo useradd -m -G video camera
pi@rasp-pi4-dash ~ $ sudo passwd camera
pi@rasp-pi4-dash ~ $ sudo -iu camera
camera@rasp-p4-dash ~ $ mkdir -p front rear sound logs/tmp usb/front usb/logs/tmp
camera@rasp-p4-dash ~ $ echo "0" > /home/camera/usb/logs/tmp/event.ct
Change the file permissions so the camera directories are available to all.
camera@rasp-p4-dash ~ $ chmod -R 777 /home/camera
camera@rasp-p4-dash ~ $ exit

- Install the 'motion' program for the USB camera
pi@rasp-pi4-dash ~ $ sudo apt-get install motion

- Edit the motion configuration file and modify some of the variables
pi@rasp-pi4-dash ~ $ sudo vi /etc/motion/motion.conf
daemon on
width 512         <— change to suit your camera
height 288        <— change to suit your camera
framerate 12   <— change to suit your camera
max_movie_time 600
emulate_motion on
output_pictures off
ffmpeg_video_codec mkv
target_dir /home/camera/rear
movie_filename %Y%m%d%H%M-%v
stream_port 8080
stream_localhost off
webcontrol_port 9080
webcontrol_parms 1
Near the end of the file, remove the comment ';' so we can use a camera specific configuration file
camera /etc/motion/camera1.conf

- Install the 'wiringpi' software so we can access the GPIO pins.
pi@rasp-pi4-dash ~ $ cd ; mkdir wiringpi ; cd wiringpi
pi@rasp-pi4-dash ~ $ wget https://project-downloads.drogon.net/wiringpi-latest.deb
pi@rasp-pi4-dash ~ $ sudo dpkg -i wiringpi-latest.deb

- Install the GPS software and add your GPS device to the configuration file.
N.B. If you do not have a GPS device but wish to use 'picam.py' for the Pi camera the gpsd program still needs to be installed.
pi@rasp-pi4-dash ~ $  sudo apt-get install gpsd
- Add our GPS device to the configuration file.
pi@rasp-pi4-dash ~ $ sudo vi /etc/default/gpsd
DEVICES="/dev/ttyAMA0"
GPSD_OPTIONS="-F /var/run/gpsd.sock"

Unfortuantely hciuart/hciattach takes our serial connection to /dev/ttyAMA0. To free it up we need to disable it by editting '/boot/config.txt' and adding 'dtoverlay=pi3-disable-bt'. Sadly however, this disables bluetooth. If anyone has a better way please let me know.
pi@rasp-pi4-dash ~ $ sudo vi /boot/config.txt
[all]
dtoverlay=pi3-disable-bt

(A reboot is then required)

- Download the dashcam scripts
pi@rasp-pi4-dash ~ $ sudo -i
root@rasp-pi4-dash:~# cd;wget https://"drive.google.com/uc?id=1hKQTJ4sLpXROPjRr42hTni8Zmx_xVid6&export=download" -O scripts.tar
root@rasp-pi4-dash:~# tar -xf scripts.tar;chown -R 0:0 scripts;rm scripts.tar
In the 'scripts' directory edit 'global.rc' and change the settings to your needs.

If you do not have a GPS device change the settings in global.rc to this;
GPS_enabled             no              [yes] / no      If 'no' recording starts immediately, date and time are not set.
GPS_wait                no             [yes] / no      Wait for GPS fix before recording starts

- Configure a startup service for the dashcam script
pi@rasp-pi4-dash ~ $ sudo vi /etc/systemd/system/dashcam.service

[Unit]
Description=Dashcam control program
After=local-fs.target

[Service]
ExecStart=/root/scripts/dashcam.sh
Type=simple

[Install]
WantedBy=multi-user.target
pi@rasp-pi4-dash ~ $ sudo systemctl daemon-reload
pi@rasp-pi4-dash ~ $ sudo systemctl enable dashcam

- Extras
If you want to overclock your Pi4 to 1750Mhz add this to the end of config.txt and reboot...
pi@rasp-pi4-dash ~ $ sudo vi /boot/config.txt
over_voltage=2
arm_freq=1750

If you want to go to 2000Mhz then we need to install a slightly different kernel. For most uses it will probably be fine but this should not be done lightly.
pi@rasp-pi4-dash ~ $ sudo rpi-update
pi@rasp-pi4-dash ~ $ sudo vi /boot/config.txt
over_voltage=4
arm_freq=2000

GPIO pin details: https://github.com/RPi-Distro/raspi-gpio/commit/80fa7d04eafb3ea34fc6f2d32de5f1873b5fb369