Power saving on hot tub, and what not to do

I have posted much on the hot tub. It came with the house, and has been a huge lesson.

Hourly check, some heating, and 13:00 jets

I have also posted how it goes off, and how lately it is a lot better, and I think I finally have the answer.

So this is posted as a word of warning.

Saving power

Something I did early on was put the hot tub on a timer. On during day so I could use it, and on from 2 to 5am to use cheap electricity to top up. The logic of this saving time heating, vs constantly on and allowing thermostat to go on/off, is not clear, but the main saving was that it used cheap electricity at night for a big chunk of the daily usage. So even if heating as long, it was heating cheaper.

Initially this still meant a lot of use, but I have since insulated the internals (lots of pipes with no insulation in there), and moved to a heat pump (less time on, and less power used when on). But still on a timer.

Symtoms

The key problem was that every couple of months it would go off. Start going cloudy, dirty, and getting pH right was almost impossible. No, changing filter alone did not help. So I would empty, and refill, at some cost to reheat a whole tub. Some people were understandably puzzled I had this issue. I was resigned to it being just how it worked.

Obviously I had to add water due to evaporation, ensure chlorine and algicide, and change filter occasionally. But it would still go off after a few months regardless.

What was less obvious is the occasional use by someone that is not me. I would lie there and read, and it would last a few months with no issue. But some times, someone else (relative) would use. On one occasion I berated someone for leaving the tub filthy - so much so I emptied and refilled. It was dirty and cloudy after their one use. I hereby apologise, as I think not their fault.

One clue was Alice, my granddaughter, who uses it when she is here, and usually fine. But on one occasion, after the tub have been a couple months since a refill, she used it, with me as well, and she had a shower first, and I could see she had not dragged in dirt from the garden on her feet, and it was quite a short session. But after use, it was cloudy and dirty. How?

Using a timer

I believe I have solved it, and it is totally silly. Be warned!

The hot tub has water jets, as many do. And these have a lot of pipes (one reason I insulated them all). I don't use the jets when sat reading, but Alice likes them, and so do others.

The hot tub is not stupid, it runs all the water jets for a few minutes every day. In the early days this did surprise us when using it. It seems to do in the afternoon and not sure I can control when. It also has a circulation pump I can control for twice a day for the main tub.

But it has no persistent clock, so the timer meant that twice a day it started as midnight. And was not getting to what it considered afternoon. So did not run the jets, at all, ever!!!

You can imagine the effect, water in lots of pipes, never moving. Even with the chlorine and algicide, and changing filter, this did not help that water stagnating.

Even with no use of the water jets, after a few months it went off, but using the jets would just circulate that all and leave the tub dirty and cloudy. This explained why Alice, and others, using it (with water jets) made it dirty.

Not using a timer

The good news is that now I am not using a timer, it is not going off at all. Yes, I need to change the filter. If I leave it without topping up the chlorine, etc, it may go a tad cloudy, but immediately clear up when I top up (this did not work before). It just says clean, and clear, and nice.

As for cost, well, using heat pump and having battery, and the extra insulation, mean it uses way less power now, and when it does is often from battery that charged from solar, or cheap night electricity. So running 24/7 is nothing like the issue it was when I first started with it.

The house uses way more than average domestic, but even so, several months over the summer we had a negative electricity cost, even with a hot tub on 24/7.

So using a timer on your hot tub may be bad, be warned!

Working with a factory (ESP flasher board)

This is an interesting one for some people I am sure.

We (A&A) do work with (UK) factories for some of our products, and it is interesting, but we get to visit the factory and see that we are happy with how they work, and we provide ATE kit. This is Automated Test Equipment. It will flash code on to the circuit board, and run self tests. In some cases they have a number of Ethernet leads to a test switch as well so it can self test all the Ethernet ports as part of the process.

But as you may know, I get lot of small dev boards from JLC in China. These are great, but they had a few issues with placement and soldering on the main ESP32 module lately.

The solution they propose is that I order some boards with a "functional test". This means I need to make an ATE for them, and send to China. They are going to do the first batch of boards with the functional test for no extra cost, which is nice, and I am going to try and get them to bag and label as well rather than their usual foam and bubblewrap annoyance. Fingers crossed that they can do that and that it is a sane price compared to my doing it. We will see.

The big reason for this is that they don't ship the failed boards, they debug them and fix them, so I don't end up with duff boards for which I don't have the equipment or eyesight to fix. The downside is this normally has a small extra cost.

But this has meant making a Flasher board. A device that can flash code on to one of my dev boards, and report clearly a self test pass or fail. The result is this. It is useful outside of the factory, maybe flashing Tasmota on Shelly boards, or just flashing boards I get in smaller quantities here. It is neater than using command line on my computer and has nice visual feedback on progress.

USB power, and a 6 pin RJ12 or USB-A connector. In this case the 6 pin RJ12 is to a TC2030 connector which plugs in to my boards.

This trick, and a lot of iterations in the code this week, has been to make it as idiot proof as possible.

It flashes from SD card, and can update image files over the internet automatically. It allows up to 10 different flash manifests by button press. It flashes multiple files in different places. It runs the code and waits for ATE: PASS or ATE: FAIL from the device. It provides a loop back link on the TC2030 even so my boards can do a loop back test on the final connection pins as part of their self test.

I have made a video to show the factory - I really hope this is as idiot proof as I hope.

One of those days (Amazon)

I am not looking forward to another lengthy and pointless discussion with Amazon... They really are not fun.

What now?

UPDATE: SOMEONE AT AMAZON FINALLY UNDERSTOOD. PICK ME UP OFF THE FLOOR NOW...

I have listings for things like this...

It is described as "with 3 pin WAGO". The fact it has a WAGO connector is useful, as it is a lot better (in my view) that any sort of plug/socket arrangement or screw terminals, and takes less space as well. It is ideal for this sort of thing (LED strip controller).

Amazon seem to feel that using "WAGO", a trademark name, needs a letter of authorisation.

Thankfully I know someone who is good at pointing me to legislation, and, as I expected "Nothing in the preceding provisions of this section shall be construed as preventing the use of a registered trade mark by any person for the purpose of identifying goods or services as those of the proprietor or a licensee".

So, yes, I can describe the 3 pin WAGO connector as a WAGO connector. I have tweaked to be clear, changing "with 3 pin WAGO" to "with 3 pin WAGO connector", just to be extra clear. And quoted the Trade Marks Act 1994 section 10(6) to Amazon.

I do not hold much hope that this will be a simple "OK, that's fine". But they may yet surprise me. We'll see.

Update: Yep, stock replies, this is going to be a long one.

I've also added this image to the listings :-)

Finally Amazon

It seems only fair to say that Amazon have finally recognised a brand, and so we can now list products once again.

I am not sure we have resolved EAN re-use yet, but at least we can list new products, and have listed a Faikin S21 cable and case.

So well done, even if it took months, and a blog post, to get it done.

Maybe I'll try and get some of our other trademarks added!

Nice neighbourhood

I live in a nice neighbourhood. Really... Well, I thought I did.

After 4 years here this is the first time someone has literally taken a parcel off my doorstep!

Criminal video

To say I am shocked is an understatement.

I never imagined anyone would do this.

I am, however, impressed that the local police has a web page for crime reporting and it seems mostly sane!

Also impressed that they have called me for the raw video so they can try facial recognition.

QR abuse...

I'm known for QR code stuff, and my library, but I have done some abuse of them for fun - I did round pixels rather than rectangular, for example.

The latest abuse was inspired by https://mathstodon.xyz/@divbyzero

His idea was a Truchet style...

I have done some more work on the idea. For a start I did not like the harsh edges and cut circles, so made it slightly different. I also had concerns on the circle hitting the targets as this may cause timing issues perhaps.

Looks good. But I also tried larger and it had trouble reading at an angle, and I think because I had Truchet coded the alignment marks needed on larger codes.

So I made them rectangular, e.g. same code as above with alignment mark intact.

Now it reads better at an angle. (tested on iPhone camera and an app). This allows the 45 degree shown at the top of this blog post.

Do not blame me if you now have a migraine, please.

Oh, and if you are interested, this is created as a proper QR code, but with a grid of black/white circles on top... I have made a video https://www.youtube.com/shorts/9ufN2cpsbPA