EVNotiPi

Work In Progress.
Adapted to suit MY hardware, some of which I already owned (OBDLink MX+, USB GPS antenna, Huawei MS2372H-517 4G Modem). I don't suggest that someone else repeat these steps, as I would do things differently if I had to do it again. But I still want to document what I did, mostly for myself:

Python Version of EVNotify

Needed Hardware

• Raspberry Pi Zero W with GPIO Header https://buyzero.de/collections/boards-kits/products/raspberry-pi-zero-w-easy-mit-bestucktem-header
• OTG cable for Raspberry Pi https://buyzero.de/collections/raspberry-kabel-und-adapter/products/micro-usb-zu-usb-otg-adapter
• Small wires in different colors: https://www.amazon.de/AZDelivery-Jumper-Arduino-Raspberry-Breadboard/dp/B07KYHBVR7?tag=gplay97-21
• LTE Stick Huawai MS2372H-517, which works for me in Canada. I had great difficulty finding an LTE stick that works in Canada. But I didn't realize before buying that this stick did not have Wi-Fi, so it complicated my setup by forcing me to buy a USB hub, which wouldn't be needed if if the Pi connected to the Internet via Wi-Fi. If I were to buy again, I would try and find one that has Wi-Fi. Setup would have been much simpler.
• Rapberry Pi USB Hub, to be able to connect both my LTE stick and the GPS antenna: https://www.amazon.ca/MakerSpot-Stackable-Raspberry-Connector-Bluetooth/dp/B01IT1TLFQ
• USB GPS antenna: https://www.amazon.ca/Navigation-External-Receiver-Raspberry-Geekstory/dp/B078Y52FGQ
• OBDLink MX+ that I alrady owned: https://www.amazon.ca/OBDLink-Bluetooth-Professional-Grade-Diagnostic-Performance/dp/B07JFRFJG6. It would have been simpler to buy a PiCan. But I already owned this device and I'm cheap.
• The i2c watchdog and power supply, https://github.com/noradtux/evnotipi-watchdog. I modified this design to use a buck converter as the power supply instead of the linear regulator, and a relay instead of the mosfets, both of which I already owned (Again, I'm cheap). The (DPDT) relay also allows me to completely turn off the power to the OBDII dongle.
• OBD2 male and female connectors: https://www.aliexpress.com/item/4000087243731.html
• I designed & 3D-printed my modified version of the case https://github.com/noradtux/evnotipi-case.

Wiring

OBD2 connection

OBD2       
4,5  GND   
  6  CAN_H 
 14  CAN_L 
 16  12V   

I only connected Pin4 to Ground as it is documented as Chassis Ground. Pin5 is the Signal Ground, I wanted to make sure I don't contaminate it.

Installation

Raspberry Pi

• sudo apt update
• sudo apt upgrade
• sudo apt install python3-{pip,rpi.gpio,serial,requests,sdnotify,pyroute2,smbus,yaml,gevent} gpsd gpsd-clients git watchdog rsyslog-
• sudo systemctl disable --now serial-getty@ttyAMA0.service
• sudo sed -i -re "\$agpu_mem=16\nmax_usb_current=1\ndtoverlay=gpio-poweroff,gpiopin=4,active_low=1\ninitial_turbo=60\nboot_delay=0\ndisable_splash=1" -e "/^dtparam=audio=/ s/^/#/" /boot/config.txt
• sudo sed -i -re '/console=/ s/$/ panic=1/' /boot/cmdline.txt
• sudo sed -i -re '/max-load/ s/^#//' /etc/watchdog.conf
• sudo sed -i -re "\$adtparam=watchdog=on" /boot/config.txt

If using the i2c watchdog (the one with the Trinket M0):

• sudo sed -i -re "\$adtparam=i2c_arm=on,i2c_arm_baudrate=50000" /boot/config.txt
• sudo sed -i -re "\$ai2c-dev" /etc/modules

EVNotiPi

• sudo git clone https://github.com/DBestman/EVNotiPi /opt/evnotipi
• cd /opt/evnotipi
• sudo rm -r extras/ # Don't need this folder to operate
• sudo git ls-files --deleted -z | sudo git update-index --assume-unchanged -z --stdin # Tell git to ignore the files deleted above.
• sudo pip3 install -r requirements.txt
• sudo systemctl link /opt/evnotipi/evnotipi.service
• sudo systemctl enable evnotipi.service
• sudo cp config.yaml.template config.yaml

Edit config, follow comments in the file

• sudo nano config.yaml # nano or any other editor

Set up Bluetooth OBDII dongle

• sudo bluetoothctl
• [bluetooth]# power on
• [bluetooth]# scan on

Note the MAC address of your dongle

• [bluetooth]# scan off
• [bluetooth]# pair <MAC>
• [bluetooth]# quit
• sudo rfcomm bind 0 <MAC>
• ls /dev/rfcomm0 # /dev/rfcomm0 should appear
• sudo systemctl link /opt/evnotipi/rfcomm-bind@.service
• sudo systemctl enable rfcomm-bind@<MAC>.service

Set up USB LTE Stick

• sudo nano USBModem.rules # nano or any other editor
• sudo ln -s /opt/evnotipi/USBModem.rules /etc/udev/rules.d/20-USBModem.rules # Install USBModem.rules : http://reactivated.net/writing_udev_rules.html#why
• sudo udevadm control --reload-rules && sudo udevadm trigger # reload udev rules
• sudo apt install wvdial
• sudo mv /etc/wvdial.conf /etc/wvdial.conf.bak # back up old configuration file
• sudo ln -s /opt/evnotipi/wvdial.conf /etc/wvdial.conf # use my wvdial configuration file
• sudo nano /etc/wvdial.conf # nano or any other editor
• sudo wvdial # check that wvdial works
• sudo systemctl link /opt/evnotipi/wvdial.{path,service}
• sudo systemctl enable wvdial.{path,service}

Set up a GPS receiver

Verify that the GPS receiver is working correctly. If not, see a tutorial here: https://maker.pro/raspberry-pi/tutorial/how-to-use-a-gps-receiver-with-raspberry-pi-4

• cgps -s

Because of a bug where the GPS position is not updated, I added a command (ExecStartPre=ubxtool -p RESET) in evnotipi.service, to be run before evnotipi. See https://www.reddit.com/r/raspberry_pi/comments/sthxpg/why_does_gpsd_not_update_a_location_past_its/

• sudo sed -i -re '/^ExecStart=.*/i ExecStartPre=ubxtool -p RESET' evnotipi.service

Optional: Set up RaspAP

RaspAP allows the Pi to become a wireless access point, enabling access to Internet when you're in your car.
Follow the instructions here: https://docs.raspap.com/ap-sta/.
I had to uninstall/reinstall RaspAP several times before I could configure properly, but I don't remember what were the difficulties. Maybe it was a buggy version.

To uninstall RaspAP

• cd /var/www/html
• sudo installers/uninstall.sh

Optimizing Boot Time

Debug with systemd-analyze && systemd-analyze blame && systemd-analyze critical-chain evnotipi.service

• sudo raspi-config nonint do_boot_wait 1 # Don't wait for network connection on boot. This saves a few seconds.
• sudo sed -i -re '/console=/ s/$/ quiet fastboot/' /boot/cmdline.txt
• sudo systemctl disable keyboard-setup.service # Keyboard not needed for headless
• sudo systemctl disable triggerhappy.{service,socket} # Unless you have an external joystick or something that uses `/dev/input/`
• sudo systemctl mask systemd-rfkill.service # Disabling won't work. Unless you have a hardware button to disable the WIFI you won't need this