What solar equipment might be suitable for a semi-remote CCTV station?

I recently posted about a camera project, and I have another idea! Hear me out…

I am considering building a community CCTV system for a car-park in my neighbourhood. I have done some research on the legals and funding, and I think we’re alright on that front. So it just leaves the practical issues.

The main issue is that the locations are probably going to be without power. I have considered lashing up a combined power/network line from the nearest house to the first camera location, but with each location I am considering, the viability of this is cumbersome to start with, and gets progressively harder with each one.

I think the first location will be in Wi-Fi range, and we can put an external repeater on a nearby building to improve connectivity.

My hardware choices currently look like this:

  • A Raspberry Pi 3B (replaced by a Pi Zero 2 when available)
  • A 12M camera module
  • A solar panel
  • A lithium or lead-acid battery
  • Small drive (e.g. mSATA) for reliable storage (optional)

The mode of operation looks like this:

  • Wi-Fi device on the Pi is put into hotspot mode (so it does not join a network, it is joined by something else)
  • Camera writes footage to the SD card in ~10 sec bursts
  • File system is shared over the network using Samba etc.
  • Remote system connects to the hotspot and “consumes” each finished file (i.e. saves it elsewhere and then deletes it from the camera Pi)
  • If there are several cameras then the remote/central consumer would either connect to each one in turn, or would operate several Wi-Fi devices, so it can consume from several cameras simultaneously

The idea with using a hotspot on the camera Pi is that dropped connections can be resolved externally, rather than needing to shimmy up a lamppost for a reboot!

Now the main issue is how to power the device. I am mulling a lead acid battery for its capacity - it has to work 24 hours a day, even when there is no solar energy during the night. However, lithium may work - this device looks good but I suspect the panel and battery is not large enough.

The purpose of the footage consumer is to archive footage in a safe place, so that even if the device is vandalised or stolen, the footage will survive.

Ideas to reduce current consumption:

  • Reduce resolution at night
  • Reduce frame-rate at night
  • Turn off Bluetooth
  • Reduce CPU speed
  • Reduce Wi-Fi power (depending on location)
  • Do fewer Wi-Fi consumptions (e.g. less Wi-Fi activity during the day when the equipment is less likely to be interfered with)

I plan to do some current measurements based on real-world camera and Wi-Fi usage (using a multimeter). This will give some clues as to what capacity battery is required for a 24-hour cycle, and what panel will comfortably power this. There are some Adafruit/RPi hobby solutions on the web, but I fear they won’t cut the mustard. We will probably have lamp-post mounting options, including the recommended slanted angle of a sizeable panel. Does anyone have any recommendations on the solar/battery front?

Update

I found this research on Pi power consumption under load. Given that I will start with a full-size Pi, and I expect my Wi-Fi load not to be trivial, I think aiming for the 1A bracket might be sensible (unfortunately current consumption data for the 12M camera module appears to be elusive).

The key takeaway from that article is this:

If the Raspberry PI were powered by a 1000mAh battery, it would last just under 1 hour.

So the battery I found would power it for just two hours in the dark! At a guess maybe I could make optimisations, but I doubt I’d be getting to double that figure, and even that would still fall short. I wonder if something like 10Ah would be better, for example this 6V lead-acid battery.

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If you have some 3A+'s, I’d use them in place of a 3B. They should be close to a Zero 2 in performace and use less power than a 3B. I have a bunch of 3A’s in use here as a cost saving over a 3B. They are headless setups that don’t need all the extra USB jacks etc.
There are high capacity LIPO’s out there.
High Capacity Lithium Ion Battery Pack - 10050mAh (pimoroni.com)
If you do go lead acid I’d go with sealed gell cells.

Have you considered doing it with a Micro Controller? Assuming its actually doable, power usuage would be a lot less. Plus it would be tolerent of sudden power loss.

If you have some 3A+'s, I’d use them in place of a 3B.

Thanks for the suggestion. Sadly I do not - I have one lonely 3B, which I might play with to get the hotspot and Samba config working, before I can get my grubby mitts on a Zero W 2!

There are high capacity LIPO’s out there.

Thanks for the link to the Li-Ion battery, that looks very good. I’ll see if there is any solar charging info on the Pimoroni site.

Have you considered doing it with a Micro Controller?

I’d definitely be open to it, but I’ve assumed up until now that a hi-res camera would supply data faster than such devices could process. I’ve done a bit of research on Arduino and Sparkfun boards, but in the rare cases they are paired with a camera, the res is in the order of 2M, which I think is too low for my use-case.

I have a bunch of Raspberry Pi Camera setups, 4B’s, 3B’s and 3A’s. So far they all run Motion Eye OS. It’s a bit outdated and currently unsuported update wise, but it does what I need it to do. I just want to view the stream over my local LAN, without having to go to the internet first. Two of my Camera setups are Pan Tilt. None are battery powered.
No Pi Pico Camera setups just yet. I was waiting for the Enviro Camera to be released but it seems to have faded to black?
I do have a bunch of Pi Pico setups on the go here. Mostly weather sensor related stuff.
I’m probabaly 50 50 between weather versus camera setups Pi wise.

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Ah, nice tip, thanks. I will have a peek at that.

To be fair though, I can see me doing things in a custom fashion - I like using other people’s software until it no longer conforms to my vision of how everything should work. The curse of being a software engineer! 😆

One nice thing from the wiki is that it suggests it can use network surveillance cameras. I will bear that in mind for my forthcoming experimentation sessions - it may greatly expand what devices I can use.

Motion Eye OS, AFAIK, was originally devloped with network surveillance cameras in mind. My usage is sorta kinda that way. I mainly want to keep an eye on my dog when she is tied up out front. I also use it to watch for parcel deliveries etc. The Motion part is turned off. If I want to take pictures or videos of birds etc, I have bird feeders, I do it maually.

When I originally researched how to do what I wanted to do, 9 times out 10 you had to setup an account and feed to a Internet WEB site to watch your camera feed. Not at all what I wanted, I have cameras setup inside my house I’d just as soon nobody else viewed. ;) . With Motion Eye OS I can view a camera feed on any browser on any device, PC or Pi, simply by entering the cameras local LAN ip address. It’s what works for me. =)

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Just to add a little research for fellow solar-users, I just found this natty battery calculator, which gives an idea of how long each Pi type will last on each given battery capacity. (Sadly it does not have a tab yet for the Zero 2 W).

Yeah, I hear ya! I am mystified why folks want to use use Ring doorbells and the like, not to mention the voice assistants to control their telly. Consumer society is practically asking for corporate surveillance, and there seems to be very little organised restraint against it.

Do you happen to know if a Zero would be OK for higher res cameras (8MP, 12MP, 16MP etc)? I am minded to think so - even the 64MP camera will do 16MP on a Zero 1. It won’t do 64MP - that requires a RP4 or CM4.

I am tempted to get a Raspberry Pi Zero WH from PiHut (as these are available at the time of writing).

I found a Pi Zero to be lacking, performance wise. I got a lot of lag and stuttering in my Video Stream

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Righto, thanks AN - good steer 🏆. I’ll stick with the Pi3 for now, and then maybe move to a PZ2 if I can get my hands on one.

I have a Zero 2 W sitting here on my desk doing nothing, and a spare V1 camera. I’ll see if I can give them a test with Motion Eye OS some time today.

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Lovely, I’d be interested to see the results of that experiment! 🏅

I dug out my old RPi3 last night, and it would not boot until I flashed a fresh copy of RP OS Lite (64 bit). Now it’s perfect, and I’m already digging into setting up a Wi-Fi hotspot.

Pi Zero 2 W is actually pretty good with Motion Eye OS. I’m using a version 1 Camera set to 1280x720 and not seeing any lag or jitters. I’m getting about 10 fps or so. It should be on par with a 3A and I get good results with those also.
Recorded some video and the playback was good.

Nice, thanks. My V3 camera came through the post today, am looking forward to trying it on my 3B. I wonder if my res/FR will be dictated by how fast I can slurp the data over Wi-Fi sufficient to keep the total data on the camera Pi static. And of course my local testing of 1-2m distances will be very different in the real world, where they will be 5-15m away with a wall in the way…

I’m sorta kinda wondering along those same lines with my setup. I have a spare wireless router that I’m going to setup just for my Pi’s that use WIFI. I want to move all my cameras over to that and get them off of my now crowded ISP supplied Router. The one supplied my my ISP is in my basement. I’ll put mine on my main floor where all the actition is.

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Small update - I haven’t used my camera yet, because my Pi 3B has taken up the role of a bastion server, and I don’t want to break it. 💥

I am very happy to report that Pimoroni are, at the time of writing, back in stock with the Pi Zero 2 W. 🎉 I have one coming my way! I shall therefore be able to do some playing around with camera recording, and to see what current draw it takes for different resolutions, frame-rates, and Wi-Fi egress frequencies.

From there I shall be deciding what solar solution to plump for. I am rather liking this panel, but I wonder if I might get away with a lower-wattage one… 🤔