Background
I've got a VW T5 campervan. It is both my “daily driver” (not that I drive much... even before lockdown... I cycle most places)... but I also use it for trips away. Mostly just a few days camping around the UK, but I've been over to the Netherlands a couple of times for XRP community meetups.
You might have noticed I spend a fair amount of time online ;) and so having good connectivity is something I like. Even when going away camping. My daughter still wants to be able to access Youtube and Netflix etc. And quite often I like going away camping and writing code for certain projects (yes, amazingly it is my way of relaxing).
So to cater for my mobile connectivity requirements, I have build a mobile base station into the van. This consists of several parts
- A Raspberry Pi running Plex as a media server and acting as a wifi base station.
- A Mikrotik Groove 52 2.4/5Ghz outdoor wifi unit with a 15dB omnidirectional antenna to connect to a campsite wifi
The goals of this setup were to achieve two things:
- Whilst on the move, or away from connectivity, allowing my daughter (and my wife and I) to be able to access a library of films/TV shows via the Plex server in the van. All my daughter's favourite Disney films are on there, and my wife's addiction to Columbo is taken care of (“Just one more thing...”)
- When we are camped on a campsite with WiFi that we can get a decent signal despite distance / obstacles in the way / many other users.
The Raspberry Pi runs all the time, and it powered by the leisure battery under the driver's seat, which in turn is charged by two 120W solar panels on the roof and/or the engine alternator.
So the laptop/ipad/phones connect to the Raspberry Pi, and then if we are onsite, the Mikrotik is connected via an ethernet cable to the Rasbperry Pi and in turn it connects to the campsite wifi. I have a 3 meter extendable mast that the external antenna can attach to to get above the height of other vans / caravans / terrain. The 15dB antenna is comically large, and looks like a light sabre. But it was what was in stock when I ordered, so I went for it (“It won't be that big, will it?“).
Problems
I am planning on heading off camping for a few days this week, and as I've not used the van much recently I thought I'd check all was working. As it happened the Wifi was not working and I remembered I'd not quite finished off the actual grand plan above. So set about fixing it.
Everything it mounted under the drivers seat, so took that out to get to it easier:
In the photo below, we have the leisure battery, a Banner Energybull 110Ah battery. Then left to right in front of it: Victron Bluesolar solar regulator, Raspberry Pi, fusebox.
The solar regulator is really nice, as you can connect to it via Bluetooth and get various stats as to how much power you are getting from the solar panels and the charging state of the battery, and how much load you are drawing from it:
Turned out the power supply to the Raspberry Pi had died. It is designed to take 12v feed from the van and drop it down to 5v for the Rasbperry Pi. Every month the solar regulator does a “balancing” charge of the battery cells and takes it up to 16v for a short period of time. I'm suspecting that may have fried the power supply.
As I'm going away in a few days, I didn't have time to wait for a replacement. Whilst I could get the same one again, I have ordered a much more capable “buck boost” converter from eBay which can take a much wider range of input voltages, and supply up to 10A output:
But I needed something right away whilst I wait for the above PSU to arrive. Hunting through the garage I found a cigarette lighter socket style USB supply. It is only rated to 2.1A, but might be just enough to power the Raspberry Pi (recommended 2.5A minimum). So set about breaking the plastic case open to get to the guts of it. I clipped it to the battery to test it, and sure enough it worked enough to power the Raspberry Pi:
So I set about soldering on some wires to it. I cut the wires off the old supply to re-use, as they already had ring terminals on the end. I even found some shrink wrap to put around the terminals. Professional!
I connected it up to the fusebox and plugged the Raspberry Pi in... all still worked. You can see at the bottom the white connector, that is a RJ45 connector in which to plug the Miktotik unit into. That is a power over ethernet injector cable also wired into the 12v fusebox. So the Mikrotik is powered directly from 12v along the ethernet cable.
So for the actual final test, I plugged the Mikrotik in along with it's external antenna (I told you it looked like a light sabre!) and grabbed my laptop to see if it could connect to the wifi back in the house.
Yay! It worked :)
I then tidied everything up and put the seat back in the van. Here is how it looks if you peer under the seat. The cat5 socket is just there read to plug the external wifi into when needed.
I did plan on putting a wooden panel on the front to just tidy it up and stop random stuff rolling under the seat, but the panel socket RJ45 connector I bought for the job is hiding somewhere in the dark recesses of my garage. So that will have to wait for another time.
And for Coil subscribers, you can see the wonderful bit of kludging together I did to create a simple way to attach the 15dB external antenna to the 3m extendable mast I have: