Tiernan's Comms Closet

Geek, Programmer, Photographer, network egineer…

Running a Raspberry Pi in a car and backing up dashcam footage

A few months back (well, November 2020) I wrote about connecting to my car with Zerotier. In this post, I mentioned using a TP-Link router running OpenWRT and a Huawei LTE dongle to connect to the internet, which allowed me to then connect to my Blackvue Dashcam and watch remotely… But it had some issues I wanted to fix:

  • The Huawei Wingle was a little slower on 4G than I would have hoped…
  • When the power in the car went out, everything stopped working immediately (12V sockets in the car run for about 20 min after the engine shut off)
  • It did not connect to the WiFi in the house when parked
  • No option for backing up Video…

So, I went digging to find some alternatives… and I realized I had a load of them floating around the house: the Raspberry Pi. Specifically, the 4GB Pi 4. I got my hands on a Pi UPS Hat, a couple of 18650 Cells and an SSD Expansion board with a 512GB (overkill I know) SSD. I also got a BlackVue Power Magic Battery, B112, which will power the Dash Cam (a BlackVue DR750S-2CH). It has 2 USB ports, which allows me to run both the Pi and the new WIFI router, a Netgear Nighthawk M1.

When the car starts, it powers, via the 12V socket in the boot of the car (trunk for my American friends), which powers the Blackvue Battery. Cables run from there to the front of the car where the front camera is. (there is also a rear-facing camera in the boot too… more cables!) This then also starts the Pi and starts charging the 2 18650 batteries. Finally, well, at the same time really, the Nighthawk starts running too. Because the batter on this was running hot, the battery is removed from this.

The Pi is hooked to the Nighthawk via ethernet and the WIFI is set to connect to the house when it sees it. The BlackVue uses the WIFI from the Nighthawk for its internet requirements. When the pi boots, it connects to Zerotier for management via SSH or VNC (I use VNC to remote into the box and watch the live video when the car is parked or when someone else is driving).

There is also a python script that is scheduled to run every 15 min that downloads the videos from the Dashcam. It also downloads any GPS and other info. The folder these files are downloaded to is on the SSD and is shared with my machine at home via Resilio Sync. To make sure I don’t use all my LTE usage, the machine at home is set to only download what I want to download. So, if the car is somewhere else, I can download specific files when I want, or when at home, I can download full days, if required.

It’s been running for a few weeks now, and so far, so good. I haven’t had to do any clean up of the SSD, yet, but I would guess that eventually, I will need to look into that… With the 4G connection and Zerotier, I can then connect to my car and watch the live video whenever it is online, and whenever it is driving, within 15 min it will start downloading videos. I could, in theory, do a LOT more with the Pi in the car… Some ideas that come to mind:

  • Turn WIFI off on the Nighthawk and use the Pi as a Router, probably adding a second WIFI adapter to get better range… This could then have PiHole running on it for monitoring DNS traffic…
  • Since I have access to the GPS files in (somewhat) real-time, use it to map the car in somewhat real-time. Though, I do this already using Ruhavik and a Teltonika FMC-001.
  • Connecting to the car’s OBDII port (On-Board Diagnostics) and getting data from the car… Technically, again, the FMC001 does most of this, but in theory, it could be replaced with something else…

Keep an eye on the blog for future possible projects with this… Not sure where this project will get me, but we will figure it out at some stage… Leave a comment if you have questions!