Car

For the last few weeks, I have been running a Raspberry Pi in my car, along with a small UPS and a Wifi Access point, allowing me to download videos from my dash cam and back them up to my NAS in the house. But I have had some teething issues, and I am currently thinking my way through some fixes…

While trying to figure out how to fix part 1, I came up with an idea: I have an older Mikrotik RB951G that can be powered via a 12v adapter for the car. I am going to use that, along with a Huawei 4G dongle to act as an internet connection. The onboard Wifi will be in client mode, so when it’s near the house, it will connect to the main network and send traffic through that to the internet (or internal NAS) and when away, use the LTE modem. Then, using the Wifi dongle on the Raspberry Pi, use that as a Wifi AP.

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:

I use ZeroTier on my network for a good few things, including internal network peering between BGP VMs, management of machines, and now, connecting to my car over LTE. This is one of those posts that sounds silly, but is very handy! First, the parts list:

• Car.
• 3G/4G/5G modem of some sort. I am using a Huawei Wingle. Can be used without the Router below, but I wanted Zerotier, so I have it in modem only mode.
• A router that supports Zerotier. I am using a modified TP-Link TL-WR703N upgraded to 16MB ROM and 64MB RAM. This is required for newer OpenWRT builds
• a dashcam that connects over Wifi. I am using a BlackVue DR750S-2CH
• Latest ROOter software from Of Modems and Men
• Patients.

After installing the the latest copy of ROOter on the TPLink (or router of your choice) and getting the modem configured correctly (this took a while) you need to install the Zerotier software though the dashboard. Once installed, I joined my Zerotier network using the CLI (SSH into the router) and the approved it though the my.zerotier.com dashboard. Once its approved and connected, you can now go to the Zerotier IP and get to the router directly. From here, you can either setup a route in Zerotier to point at the internal network behind the router, or, in my case, setup a  SSH tunnel to the dashcam. I found the IP given to the dashcam and used SSH forwarding to get to it. Finally, i used the URLs from Digital-Nebula’s hackview repo to get to the different URLs. I use this to download stuff like GPS logs, emergency videos, etc. I have to clean up some scripts at some stage for this, and plan to upload them at some stage.