Revopoint POP3 laser scanner? Life waster!

In one of those "toy" moments a few (actually three) years ago, I splashed out on one of those laser scanner things when I was messing with making up inlet manifolds for the Honda engine. I was perhaps a bit ambitious (= naïve) when I tried to scan the whole side of the engine, as it was very messy and had loads of wires, pipes, casting ribs etc, not overlooking the myriad components (alternator, ignition coil, tacho connection, coolant hose connections etc. 

However, even when I managed to successfully scan features, there came the obvious question - "what now?" And indeed what now. You end up with a massive point cloud that isn't much use in any self respecting CAD environment. It's worse than a STP / IGS file, as it is not only an unparametric and almost uneditable shell, it's not even composed of proper surfaces. 

There's an interesting tool "scanruler" that aims to convert messy scanned bodies into parameterised models. That might offer a way out of this conundrum. But first, I'd need to acquire a credible body to begin with.

So the scanner has been sitting in its box ever since, going down as one of those silly purchases you don't really like to talk about. Yes, I've had a few of those. But being a Scottish-blooded Yorkshireman ("tighter than a duck's arse"), I've lost a few hours of sleep over this unwise purchase. But perhaps there's a glimmer of life in the thing before it snuffs it forever, after all?

So, let's dig it out and install the latest Revo Scan software (Revoscan6). Can I actually get it to produce something useful, possibly a scan of the TIG torch button???

Struggled like hell to get the camera to register the test object. Finally, after applying loads of targets and spraying the thing with "scanning spray", I sort of got it to acquire some kind of images:

It's sort of recognisable.

Other side up.

You need to stitch the points into a surface, although it won't magically generate points that weren't there.

You can get it to combine several different scans of the same object - but it's really not very clever.

This wasn't going well. Let's try to scan the actual cover. If I'm going to fuck about for ages and possibly even end up with something workable, it may as well be something I might want to work with.

Again, it needed loads of spray and missed quite a few areas. After much buggering about, filling holes etc, I got something sort of approaching vaguely sensible looking scans of both the top and bottom. This was still pretty painful and it's only part way there.

The funny(?) part came when trying to merge them:

FFS. Try again, this time with the cover held in Blutak so that it could possibly scan the whole part in one go. I'm losing the will to carry on at this point.

Bugger this. I'm not going to lose any more of my life carrying on like this. I'll revert to the original plan ie model the part in Fusion.

What an absolutely fucking ridiculous waste of time and money that was. The stupid thing is now back in its box, where it will probably stay until the end of time.

As for scanruler, without a suitable body to work from, I've no means of trying it out. Ho hum.

TIG button - creating the cover piece in Fusion

So now I need to design a replacement for the original cover that houses the pot and button. The only control input on mine will be via a finger-operated pressure button bearing down on the PSR underneath.

I suppose I could dive straight in and just make the replacement cover but that wouldn't be my style. Why do that when I can spend several possibly pointless hours creating the handle as well? Anyway, rightly or wrongly, that's what I'm about to do.

Here's a collection of planes where I will create a series of cross sections.

Like this:

Then loft them together to create a reasonably organic body:

Then use the shell command to hollow it out, leaving a 2mm wall thickness:

Ooof, it's looking very much like a sex toy where the bell end has got caught in something and got cut short. That will teach it.

Now define the cutaway portion that houses the controls:

And the platform thingy that supports the controller and separates it from the torch cable / hose.

It's getting there...

Create a patch over the opening, to form the outside of the replacement assembly:

Thicken it to 2mm:

Add a tab at the rear:

And a latch at the front:

Let's make one and see how close we are to a fit. I expect this will take some buggering about:

Fresh off the printer:

Doesn't look too bad as a first attempt

But does it come anywhere near fitting? It sort of fits near the front and actually latches in place, so the latch looks like a decent attempt:

But with the latch latched, the rear tongue is then too far back. On the upside, it engages correctly without the latch engaged at the front.

So - it's too long, by about 2mm and too wide by about 1.5mm, possibly more. Even a blind fool can see that - but in my defence, it's not easy to use the ruler tool to measure between points on a curved surface or edge. So I will bugger about with the defining sketches and aim to get it to mate with the handle. It seems like a half reasonable start at least.

I will pick this up again tomorrow and finesse the various cross section sketches to better match the original handle. If I don't fuck up the various interdependencies etc, the cover should mutate towards the intended shape, ideally fitting the torch handle. Time will tell....

Fitting IP cameras to replace the expensive Amazon Blink toys

I've had several Blink cameras over the past 5 years to keep an eye on various properties and alert me to unexpected rovers. Initially this setup was used to keep an eye on my late mother's home while it remained unoccupied ahead of being sold. Then I installed them at our property following the theft of some ladders from outside the workshop (where arguably I shouldn't have left them) and then finally I installed a set at my mother in laws to keep an eye on comings and goings. She's moved out now, so I have no further need for them

The Blink system is functional but pretty basic and has some unwanted features:

• Connection is by wifi, so can be rather patchy and may throttle the bandwidth.
• The video clips are held on the Amazon cloud. While this means it's easy to access from anywhere on the internet, you have to pay for their service - currently £80 a year.
• Although you can choose to operate the system without using their cloud service (storing clips to a local USB storage device), it makes accessing them remotely rather painful.
• The cameras are battery powered and need lithium AA batteries which aren't cheap.
• Being battery powered, you can only see clips that have been triggered by the camera's inbuilt motion detection. There's no possibility of continuously streamed video.
• Recently, Blink have been offering a basic "AI" enhancement that does some rudimentary identification of moving subjects. Of course this would cost you extra dosh on top of the basic £80 subscription, taking you up to £150 a year - per site.
• Being a closed, proprietary system, you have very limited ability to modify or enhance the capabilities of the system.

So, one of the benefits of installing Home Assistant is the option to integrate IP cameras into the existing setup. And specifically for these devices, there are some pretty powerful extensions that enable AI-assisted identification of subjects / objects in the field of view, such as the Frigate Network Video Recorder (NVR).

My Raspberry Pi 5 is powerful enough for most of the tasks I expect of it, otherwise I'd need to have fitted an actual PC. However, the AI object detection function is quite intensive and would most likely overcome the RPi, so I've added a Coral USB accelerator TPU that offloads that burden. It just plugs in to a USB3 port on the RPi and like most of these Home Assistant extensions, the installation is very quick and seamless.

Firstly, I've installed an Empiretech IPC-T28IR-AS-S3 3.6mm dome camera which requires a PoE connection for power and comms. This has excellent low light sensitivity and good HD 8MP resolution (3840 × 2160). I've fitted it with its own 128GB microSD, so it has its own storage on top of the NVR system.

The mounting base houses a waterproof ethernet connection and a (redundant) power jack.

The cable has a polythene outer coat for outdoor use. I blasted a hole through the wall next to the fibre cable. Looks almost decent by my standards:

I've got Claude Code installed in the RPi itself, which is dead handy - I can literally just ask it to install stuff and it will do so, with CLI instructions I'd never stand a hope in hell of understanding, sent directly to the various peripherals, then set up the various options within Home Assistant and Frigate (in this case) to customise it to my liking and situation. It sorted out this camera config in no time, rotating the video to account for the orientation of my setup and turning off black and white night vision.

As for the Blink doorbell, it uses the same infrastructure - with the added feature of a door chime of course. It can take its power from an existing traditional (24Vac?) bell circuit but relies on wifi for the video feed. 

I've replaced it with a Reolink PoE doorbell, which means I need to run another ethernet cable from the front door to the Home Assistant system under the stairs. I connected the bell supply to it, so it may continue to work even if the Frigate system goes down.

This has a 5MP (2K) sensor, microphone and speaker, if you like that sort of thing. Although Reolink offer an app, this device integrates nicely into Frigate / HA, so once set up in the Reolink app, everything is handled by Frigate. And of course, the resident Claude Code agent actually does most of the work - my kind of setup!

The view from up there is pretty good. And the low light sensitivity is good enough that it doesn't need to revert to black and white night vision, largely due to the street light directly outside our house.

On the face of it, the doorbell doesn't show a lot more than the dome camera but it's there for a different reason and has lower resolution.

I've set boundaries for the main camera. The object detection is within the camera software (rather than Frigate) and seems to determine where people's feet are and use that to determine if they are within the boundary. It seems to work OK now, ignoring pedestrians and traffic on the road and pavement outside our driveway.

I've enabled facial recognition in Frigate, so now it will begin to build up a collection of recognised faces and objects as they are encountered. I will then be able to go in later on and name them. Then I will be able to set alerts eg when The Domestic Manager has returned home, a stranger is on the driveway or the neighbour's cat has come into our front garden. This object recognition is done by Frigate using the power and might of the Coral TPU.

Bench testing the TIG button torch controller - there's life in it!

Finally, after about a week of feeling shit, the balance between moping about with a snotty / stuffy head cold on the one hand and moping about doing nothing has shifted to the point where I just need to get on and do something, anything, before I lose the plot. 

I've been looking forward to testing this TIG button control for the Arc Captain TIG welder and it looks as if today's the day. It's tempting just to fit it to the torch, plug it in and see if it works. However, it would be a good idea to test it out on the bench first. It's quite possible that it won't so well on the torch with the HF start circuit active and/or the arc running, in which case, it would be good to know if/that the basic circuit itself actually works as intended beforehand.

So, out with the bench PSU and a DVM:

This is the smaller of the 2 PSRs I got from Amazon, which claims to be good for 3g - 500g 

First signs are encouraging. Pressing the PSR pad causes the LED to light up and the THRESH pot changes the level at which this occurs. Similarly, applying a fixed load (weight) to the PSR and twiddling the SENS pot varies the output voltage. So, on the face of it we have a functioning circuit. Of course, that may change when there's a welder arcing away in the background - but one step at a time etc.

If anything, the required pressure feels a bit excessive but I'm still needing to design a housing for the circuit and some form of finger pad that will apply the pressure to the PSR element. I may finesse the circuit values 

This is the circuit that does the gain control and level shifting:

But for now, I think I'm in the right ballpark, so I'll leave it for now.

The main ball ache is the fact that the TIG welder doesn't actually respond to inputs from the torch or pedal controls. I've been communicating with the Arc Captain team for some weeks now but so far I'm far from seeing any glimpse of a cigar. Will I be able to get a replacement out of them? I'd like to be able to control the arc from the torch as it is - but also how am I to prove out this TIG button if the welder doesn't take any notice of the input?

I may need to establish whether the TIG button circuit continues to behave when it's fitted to the torch body and the arc (and HF) are active. That must be quite a test for any torch-mounted circuit on a good day.

So, as a first test, I seem to be seeing signs of success. Let's see what happens next, when I install it on the machine and fire up the arc....

PCBA production at JLCPCB - unboxing the delivered samples

Friday 23rd - production started:

Nice thing about JLCPCB (and presumably PCBway) is that you can follow your job as it progresses through the manufacturing steps. By Sunday, the PCB seemed to be pretty much complete:

And the PCBA assembly looking primed and waiting for the PCBs to arrive:

Finally on Sunday evening, the PCBs were sent out:

By Monday evening, the PCBA assembly was done and dusted:

And I could see the shipment had been started:

Ordered 10pm @ 21st Oct, expected 30th Oct by end of day ie 9 days from placing the order - including full PCBA assembly.

Friday 30th update:

Arrived yesterday early afternoon, around 2pm. That's actually a shade under 8 days from placing the order and receiving them through the door - not bad, considering that includes PCB fab, compt procurement and PCBA assembly. 

Excitement builds...

A little bubblewrap sausage....

....containing 5 little PCBAs

They look about right.

I need to craft up a plastic cover that also implements the PSR sensor but at least it plugs in and fits within the cavity:

Here are its cousins, the ones without feelings. I increased the board outline but stayed within the torch cavity dimensions:

I'm dying to test the functions, to see if it works OK. But I also feel as if I'm dying from a nasty dose of man flu. Currently enjoying profound deafness in left ear, wonderful rhinitis and seem to be flirting with a loss of voice. This may need to wait another day or two. I have a few jobs to do such as painting internal woodwork, fitting outdoor IP cameras (up ladders) and running some Cat6 cables but they aren't about to happen quite yet.....