*beep*
Huh?
*beep*
I'm not even pressing it. Who's pressing it?
Have you ever heard of a thing called shielding? If you have, congratulations, because apparently
creality haven't. Ah no that's funny but unfair. They probably just thought they could get
away with it on this wire down here, and largely they did - except for this random phantom
clicking of the button on the screen. Encoders, because that's what this hardware button is
called, are notoriously bad at sending phantom clicks and you usually debounce it in code.
Either way it happens, and it happens a lot for me on this ender 3.
Luckily it never seems able to actually change the options and just goes from the menu to
the main screen and back, repeatedly. Just beeping. For the whole print. Like a deranged
smoke alarm.
To stop it should be pretty easy and if you're totally uninterested in the theory then skip
to that chapter, but I'm interested so let's look into it a bit.
Stepper motors are noisy, I don't mean like audible noise because yes they sure are noisy
to our ears, I mean electrically.
Of course I can't just *say* that and leave it there can I? "Oh, steppers are noisy. Everyone
knows that." What does it even mean. Well I was wondering the same.
This is what they call, whoever they are, an SDR dongle. It's a NESDR...or a NES doctor.
Actually I think it stands for noo elec software defined radio.
And it does exactly that, allows you to scan and receive across, well, a wide range of
frequencies.
Anyway I hooked it up to my PC and put the antenna next to the 3d printer.
Really cool aside here, this is FM radio, the analogue sort. This is a classical station
I listen to a lot because, you know, I like a bit of chopin now and then like anyone else.
And this is dab radio! It looks cool even if it sounds awful here in the UK because...reasons
I'm not going to get into.
I spent a good long time moving the printer's steppers around in octoprint, this is a cool
feature of octoprint by the way, you click on the camera even if you dont have one hooked
up and you can drive it around with the keyboard like you're in minecraft. Awesome.
Anyway I couldn't find a single band or frequency where the steppers were interfering.
But then I could.
watch, see if you can see it.
It's interfering EVERYWHERE. Oh dear.
I found this runs from the low megahertz to around the FM bands. Of course the other thing
I didnt think about was that it's constant while the steppers are activated, not while
they're moving. So you have to disable the steppers entirely to get it to stop. I don't
know why I assumed it would be the actual motors, rather than the driver signal, but
it seems to be the latter!
So there you go. Steppers are noisy. Now you know. And this is what's interfering with
your screen. Guaranteed.
soooo - get your tin foil hat out and unravel it, we're going to put it to a better use.
Sorry, I know it's 2021, I guess you can make another later.
Wrapping this extremely colourful ribbon cable in foil should ought to fix it, but bear in
mind the back of the control board is also totally unshielded so if you still have issues
then I would recommend somehow trying to shield that too, but be careful because it would
be pretty easy to short out the connections.
See if you can do a better job than I have, it wouldnt' be hard now would it.
There's just time for a quick disclaimer
For extra points print out one of these things - link in the description below. You just
stick it in and turn it,
hngggggg! sorry I'm adding the sound effect in editing because I filmed it without sound.
As you do.
It's quite stiff but rock solid and you put a cable tie through like so, and hold your
cable in place!
With that done, you should get no more random beeps. Fixed it for me.
Oh wait.
(me pressing the connection with metal)
Nah just kidding.
See you next time, thank you for watching.