Pi Camera NoIR mod (daytime/nightime)


Out of the many things I didn’t need but bought nonetheless in recent times, the Pi camera is the one I had to think the hardest to put to good use :D

This will be an ongoing project as I learn my way into the world of sensors and other singularities…

chapter 1: ‘Pull my finger’ or rather ‘Push my button’ (the opposite, quite obviously, of ‘Don’t push my button’).

Although I’m unlikely to ever use it for this purpose (see a recurring theme here) I wanted to see how good a mod I could do adding a trigger for raspistill for my Explorer topped Rpi A+:

To the right, you can see a specimen of the push switch I used, it’s a standard power/reset for PC basically.

You can see it afixed the Pi case as well with a patch of double sided tape (strong adhesion). Jerky cables then loop round the GPIO out of view.

And then there is the ‘piece de resistance’ (pun intended), a 10K resistor hydra that probably breathe out fire in all directions when I’m not in the room.

For those interested the legs are bent into shape and soldered to 2 right-angle pins for the GPIO breakout on the HAT and a straight pin to close the 3.3v live link. Here it is all mounted:

And just in case anyone is interested in how the camera ribbon cable wraps around here is a view from the bottom of the Pi (complete with fingerprints and reset switch):


chapter 2: ‘Are you mugging me?’

So, I decided to take a few mug shots… I won’t insult anyone posting the code here, there is nothing spectacular about it, so let’s cut to the cheese!

What? don’t I look good in the pink? I’m sure I told you it was a NoIR right?

Enter our friend the IR filter!

… I’m not sure if there is a reliable source for those so I’ll just post the ebay listing I got it from and hopefully any party interested can find a channel to get to one of these shinies (Chinese?):
They are 9.5mm in diameters. Transmission >95% 440-620nm, down to <1% 700-1050nm

and here’s what you can expect by placing one in from of a NoIR:

… now, since I’m making this up as I go along, I haven’t figured out how I was going to attach it in place. Especially since I am planning to use the cam for nightshot as well, so will want a removable system, or some way to push it out of the way (maybe rotating it around an axis?)

But I’m going to focus on the NoIR shots for a while so I guess I have time to mull it over ;-)
In the meantime if any one has a suggestion, feel free to pitch (black) in!


chapter 3: Tilt death do us part!

Today I spent a couple of pounds. Yes, OK, 3 with the coke I got on the way back from (G) town. And I mean Coca Cola, obviously (at that price).

As usual, totally random visit to a random place, resulting in as random an update as previous installments on this project! But I think a few of you will like how I spend my money and my evening, and maybe will pay a somewhat less random visit to Pounland in the near future!

So what did I find? the answer is… for a start this:

Realistic? I don’t know about you but if any burglar falls for that one they never had their fortune told ;-)

Anyhow, we’re not here to keep this thing intact so let’s get the hammer, err screwdriver out!

there is a lot of gear for your money in this thing huh?

actually, for a pound I guess there is, just the housing for the AA bateries is worth it already, and I now have a latch switch which I guess could come in handy.

But this isn’t what I was interested in, nope. I naively had hoped that the tilt platform would be operator defined, but as you can see it’s a fixed 45 degrees angle. But nevermind that, where would be the fun if life granted you what you wished or needed… the victories (or defeats) you remember are the ones you fought!

10 minutes later, after shaving the side gutters, drilling 2 holes, cutting nylon screws, sawing the minaret, snapping the plate in half while checking how soft the plastic was, then gluing it back together while no one was looking :D

… here is the result:

my application does not need any more than that but it would be trivial to drill throughout if you needed more stability to action the tilt constantly (or perhaps motorize it). But it’s a tight fit as long as you are using some M2.5 screws so that will do for me, especially as I work on the prototype.

anyhow, here is the thing in a couple of positions, just to show off my finger!

the last thing that needed to be done was to fix the support to the raspberry case:


chapter 4: making a head start

… I think the suspense went on for long enough… ‘so what’s that other thing you bought last week Rogue, I hear you say?’

yes, indeed, what was it? yeah, that’s right, a head lamp. ‘A head lamp???’, I hear you say… yep, that’s right! Let me shed some LED on the matter for you:

Not bad for a pound…

Next step was to modify the base of the previously introduced ‘realistic’ surveillance camera, and clip the head lamp support - you’ll see why in a moment, sometimes stars just align, and notches too (and I don’t mean ‘noche’ as is ‘night’ in italian, that would be a very obscure joke to make and I’m not bright enough to even think of it in the first place!):

But, as you can see, while things seems to present themselves favourably, the cherry does not always suit the cake… or something like that…

But then I remembered Robocop… you know sometimes sacrifices have to be made for the greater good… or something like that…

and what’s a head lamp without a head? that’s right, a lamp! So let’s be utilitarian to the extreme, as murphy’s law taught us (hum, somehow I think my wires got crossed there):

… striking resemblance don’t you think?

anyhow, I guess the moral of the story is that the end justifies the means, and I got a result:

Next time I’ll show you how I ended up devising a system that allows me to set the angle for the camera to aim at but that’d do nicely for now. Buenas noche!