Battery powered board

OpenMic Audio recorder

I have a few of my ESP32 boards which are battery powered.

The charging side itself is not too hard A TP4054 can charge a 3.7V LiPo from 5V USB. A simple regulator such as ME6211C33M5G can regulate from the battery to 3.3V.

The ESP32-S3 has a number of low power modes, meaning you can make a device, e.g. a Watchy, which can run off a small LiPo for weeks with the ESP32 in a low power mode for longer periods.

But there are a couple of challenges. One is powering down other stuff on the board - a good example being the WS2812 style LEDs - these use a small amount of power even when not lit. A simple fix for these is a point of load device like TPS22916 - it acts as a power switch and can easily cut the power to parts of the board.

Simple charger circuit

But what if you want to have an off mode, where, instead of running in a low power mode for a few weeks you want something that uses no power when off, and holds battery charge for months or years (subject to internal leakage). My OpenMic Audio recorder is a good example of this.

The answer is to used the TPS22916 to control the power to the whole board, including the processor.

I tried a couple of times and now have this circuit design...

Power on circuit

To explain this... The switch SW3 is a nice little push button. When pressed it connects the battery (pin 3) to the ON input on the TPS22916. This powers on the board (VSWITCHED).

The very first thing the software does is set PWR GPIO to output HIGH level. This, via the diode (because GPIO is 3.3V and battery is 3.7V) holds the ON pin high.

Releasing the switch disconnects the battery from ON pin, but the PWR holds it high and keeps power on.

Separately the software sets the BTN GPIO to an input, weak pulled low. This is connected to ON which is connected to PWR (3.3V less a diode). This allows the software to read this as high when button not pressed.

Pressing the button when on simply changes ON from 3.3V to 3.7V and has no effect, but it disconnected BTN, which goes low due to weak pull down. Thus allowing the software to detect button presses when running normally.

Finally, when turning off, the software sets the PWR output low. The ESP32 actually has a mode to hold a GPIO at a level over reset, which allows the pin to be held low as the processor loses power and goes in to reset (brownout detect).

Once off, the whole board is not powered and only power usage is the tiny amount the TPS22916 may use, and any used by idle battery charging TP4054.

So far tests show that even after months, my audio record still shows a full battery level when turned on.

Finally I have simple potential divide in to an ADC input from VSWITCHED to allow battery level estimation.

Next steps: There are chips designed to use fuck all power but provide a configurable periodic wake up output. These could be used to power on the ESP32 periodically, much like the low power mode on the ESP32 itself, but lower power - so devices could wake once a day, for example, and run of a battery for years if needed.

Conspiracy theories

Someone just asked me...

"can anyone name a conspiracy theory that has not come true?"

Well...

Santa Claus.

I mean seriously, it is THE conspiracy theory - millions of people all working together to perpetrate it at every level - parents, relatives, companies, film makers, even US Defence Santa tracker. It is a massive, huge, co-ordinated, conspiracy way beyond what flat Earther’s could imagine. It really is...

It is almost as bad as most religions

Easter bunny and tooth fairy do not get close.

So... My kids, and even more so my grandkids... Santa has been sold as make believe, fun, let's play a game.

Never sold as reality, always a "pretend" and "fun".

I feel massively happier about that approach than selling as "real" until you get older.

It also causes issues with trust, I think.

If there can be a massive conspiracy, as there really is, of "Santa Claus", what, and whom, can you trust. 

And religion is another one - sell as "some people have these ideas and it reassures them, but think for yourself", and "there are some things nobody knows for sure, and you can consider". Religion can be a comfort for many. I am happy with that as a "comfort", sort of. 

We can always have "fun" and "fantasy". Indeed, it should be encouraged, but as such.

But, I really understand why some people come to religion.

I have really not.

I had a proper CoE background (school and parents), but quickly worked out Pascal's wager, and then realised that only worked with one specific "God or not" and so not a thing. No way to do with many Gods.

I understand people find comfort in such things, and why they want to feel comfort in such things.

I prefer to feel my own morality and my own judgement or my own actions, than something divine over me. I am responsible for what I do.

Telescope issues

 New video

So, sorry. First off, yes, still a cough.
Um, almost gone. Clearing up a lot.
triggers it. I went outside for 5 minutes in the cold, triggered it. Ihave doctor's appointment 16th. I will, if it's still going, talk to them. So, panic nod.
However, today's rant is about a telescope.
So, my well, one of my granddaughters has expressed an interest in the night sky, stars, telescopes, and the like.
And I thought, well, let's help get her a beginner telescope. And I Googled a bit and I probably fell foul of some AI because what I found was um a review of a Sonara telescope that was apparentlyquite good as a starter kids telescope.
And so I went to their website and there it was and it's 169 quid.
And I'm thinking, well, firstly, obviously, my granddaughter is worth this.
Duh. Um, but, you know, it's it's not cheap. Claims to have, you know, really advanced optics and whatever.
Anyway, based on the review, which in hindsight I think the review was just but anyway, based on the review, I ordered one and it's from a site that has UK in the domain name and charges in poundsand then ships from Hong Kong for sake. And I hate this. The website does not have on it who the legal entity you're buying from is.
And this is actually I think a legal requirement. Uh and they don't.
Anyway, let's see what I got.
It's a telescope. Okay.
F370.
I think the 70 is the aperture and the 300 is the focal length. Okay. Let's just go around the sides the end. Now, I'm not going to open it up because there's no more information in there. Okay.
Okay, fine. Um, it's a telescope and it kind of meets the spec of the ...
It has no manufacturer name, no country of origin, a CE mark, but the suppliers seem unwilling or unable to provide a declaration of conformity which is a requirement as part of a C mark.
So essentially this is a scammy illegal fake CE toy telescope.
I'm not saying it doesn't work. I'm not saying it doesn't even have the aperture aperture and focal length it claims.
What can I say?
But it's a scam.
If I go on Amazon, I can find this for as little as 20 for the same telescope. So I quered and they said, "Oh, no, no, it's not toytelescope. The optics are way better." Blah, blah, blah. I said, "Fine.
Declaration of conformity." Oh, no. We can assure you it meets all the standards, etc. No, declaration of conformity. Requirement for a C mark.
No, no. I mean, I went around the whole we can't read your emails. Your email seems to have the weird attachment. It's just a signature. Um, uh, they replied to me saying, "Your email seems to be blank." But I heard this before. The reply quotes my email which is not blank saying your email seems to be blank.
This is not an uncommon thing etc etc.
We're going around circles and I'm basically saying if you cannot provide a declaration of conformity then your C mark is fake. Therefore you cannot legally sell your product. You can't do that because you've got no manufacturer ID or country of origin anyway.
Therefore, I need to report it to the authorities and my bank and get a claw back.
Sad.
I was ripped off. I fell for it. I'm an idiot. I'm sorry.
Now, what I've got, Alice, now and have a look at this. What I've got Alice now is 260 quid. Okay, this is clearly an actual telescope.
Just the very fact it comes in a box labeled 14 and a half kilograms is is a clue.
And we put it together and she is so excited to go out in the night sky with this. I've got her some books on specially aimed at kids looking at the night sky.
So, I've got those. I hope she likes it.
If she doesn't, she doesn't. But this is a real telescope I've now gother. So, I now need to sort out this that I fell for, which is clearly a toy telescope that's worth 20 quid, charged 169 quid, and an absolute ripoff with I mad.
So, that's my latest rant.
I hope to follow up with her exploration of space.
I I really hope she loves it. I hope she gets pictures of Jupiter's moons and Saturn's rings and nebula and whatever.
There there's a lot she can look at.
and they're planning a a sort of camping trip to take her onto the moors um with her telescope and it's got a whole clip thing for a mobile phone so she should be able to get lots of pictures straight off it. It's good.
Yeah, but the toy telescope is either going back or getting clawed back or something.
Don't fall for that crap, please.

Losing my dad.... Fuck facebook.

Hi.
I did a thing today.
What I did was kill off Facebook. No, actually, I killed it off quite a few days ago.
Facebook came up with a choice.
Pay or don't pay, and don't pay is we're going to trawl what you say and what you do even more than we did before.
And I thought I'll try it without a few a few days, you know. I did.
And then finally today I went for the whole, delete it all.
Okay, I've downloaded 2.28 28 gigabytes of stuff I've posted on Facebook just as an archive, but it's gone.
Facebook's now gone.
And what hadn't really hit me was there would be one thing that would also go, and it's this.
Oh, get out.
Ah, right.
Is this is this it's a Facebook portal thing.
And then I realized that hasn't been used for quite a while.
And the reason it hasn't been used for quite a while is we got it during COVID.
I got those for everyone in the family during COVID so that everyone could instantly video call anyone else or group of people during COVID. So, we're talking six years ago.
And the one person who kept that going for way longer than anyone else was my dad. He would randomly call me on that and it would be on my desk here and it would pop up. Hi, Dad. How are you? who have things, you know, and he called lots of other people with it, but it was the one non- tech thing that he was happy to use and his sister was even happy to use at one point.
I think she gave up on it sooner than he did, but they died within like a week of eachother. It's which is really sad.
But it was the thing that he kept using for longer than anyone else and it's been sat on my desk for years now and finally I've taken it off my desk because I've given up on Facebook.
I think I might be able to make it work with WhatsApp. I have no idea. I'm not sure how long I'll stay on WhatsApp. But yeah, the hit of leaving Facebook meant leaving that which meant that was amemory of my dad was unexpected.
I've still got all the last IME messages he sent, but we all move on. It's sad, but that was unexpected. So, that's today's thing. Apart from the fact the cold seems to be clearing up. It's not completely gone. It's really, really clearing up. So, okay.

fi and ffi and really old tech impacting modern PDFs

Yes, some shit from so long ago impacts things today...

 

Okay. Hi, I had an interesting complaint from a customer today where the document we sent them demanding payment of a direct debit notification had weird errors on it.

Now, we sent them a notification of direct debit collection and a PDF and the PDF when they viewed it when they printed it. So they printed it and scanned it and sent it to us which is you know a lot of effort.

Every digit on that document, the date uh everything and the bank details and so on were all fives. Every digit was a five. And it wasn't even a complete five. It was like a truncated five. It was very messy

And there was also a weird thing where the word notification was notation.

Um, which doesn't make sense.

And this brought me back this brought me back a lot of decades. I mean, I don't know how many decades.

We've got to be talking 45 years, maybe.

My dad had a printing press. 

He's he actually had several over the years, including a big industrial one 

But he had a printing press.

And so he would compose things to print with an uppercase and lower case. And in those days that meant a wooden case of lead type upper and a wooden case of lead type lower.

And it had all of the letters you'd need.

And one of the letters in this was an FI.

Looks like this.

And there was also FFI.

That's not a terribly good example of an FI, but the the point is the FI sort of merged together where the dot over the I became the top of the F as a single lead character.

And that was the thing that that that's what you used.

Now fast forward today, we have.

Now first off just to address the complaint. The direct debit notification has plain text ASCII saying all of the details about the direct debit notification. everything, the amount, the account, the name, everything in plain text. Paper ASCII.

We may go as far as some UTF8 encoding of a pound sign, I think, and that's about as far as we go. But even that would still be readable

But we also add a PDF. And this is just a courtesy. People like this.

The PDF we use by default uses a font which has an alternative character set for the digits. So the digits can either be really fancy different sizes huge descenders weird or unified sort of spacing of the digits.

Now for any accounting purpose you want the digits that are unified spacing. You want digits that line up. And so by default, we use this alternate version of the character set on the font to make the digits line up and most things show it fine. The downside is copy and paste from it tends to be messed up, which is a real shame.

And I'd love to find a way of making that work. And it's all down to go script and god knows what. But anyway, most PDF viewers of the PDFs we send show the characters correctly.

This particular customer, I don't know what they have, but it shows all the alternate digit characters as a five.

So, everything was fives. What can I say? It's mad.

But a clue as to how bad it is is the FI character in the word notification did not show correctly, which gave gave him the wrong spelling, layout, whatever notification

So this just gave a clue of how bad his PDF view is. And what struck me is how this goes back to the days of that lead type, those 45 years ago and how that's impacting something happening in 2026 and that is just unbelievable.

So yeah, happens. Wow.

Crazy.

Time skip

I was pondering...

There is, as I recall, a film that has a guy finds some universal remote that, amongst other things, allows him to skip forward. The moral of the film is he skips over his entire life and regrets it.

But this would, some times, be cool - right? It is 4pm on a Saturday and I am doing nothing special, watching TV (a show I have watched before) and a bit hungry - if only I had a magic button to make it 6pm and I could order Chinese now.

But yes, massively tempting to "skip" more and more, I am sure.

To be fair, if I had a magic button to skip ahead I would want it to not eat from my life time as well, that would be way more sensible.

But we sort of have this - it is sleep - we can skip over 6 to 8 hours of time over night (and use up some of our life).

It is almost a shame we cannot simply choose exact periods that would be handy to skip instead, maybe.

Special neighbours

The video kind of says it all...

Hi. 
 Yes, I still have this cold. It's come 
 back. Don't ask. 
 But I've had a weird weekend. 
 It started with early hours of Saturday 
 morning where two jobs decided to take 
 concrete slabs off the wall outside my 
 house and dump them on the A40. 
 uh police did attend and the good news 
 is having given them all the CCTV is 
 apparently they actually have suspects 
 which is great. So we'll see how that 
 goes. It's not the first time we've had 
 this before but we suspect it's the same 
 people as before. 
 So that's going to be interesting to see 
 how it pans out. 
 But then later on Saturday we had 
 something a little bit unexpected. 
 A guy walking his dog decides to take 
 the Christmas wreaths off our gate. Now, 
 to be fair, we've been meaning to take 
 them off for a while, but we haven't got 
 around to it. 
 And he dumps them behind the gate, and 
 the result is they get run over. 
 Basically, uh my one of my kids came up 
 to the gate, open the gate, can't see 
 the wreaths because they're right up by 
 the gate. It's under the under their 
 bonnet, and drive over them, smashing 
 blessings. 
 We're kind of hoping we can kind of 
 recover them now. Replace some Bbles, 
 check the lights work and things, but 
 they're probably about 50 quid each. 
 Quite large Christmas wreaths. So, not 
 funny. 
 So, I put a poster up on the gate 
 basically who does this and and a Grinch 
 image and some pictures. 
 Well, guy with his dog comes back. He's 
 obviously not amused. 
 And you know, I was half expecting him 
 to just like rip the poster off as he 
 went past or something like that, but 
 no, you won't believe this. 
 He seems to have planned a midnight 
 raid. Okay, half past midnight. 
 He's got a woolly hat, different coats, 
 hand over his face, and 
 he sort of creeps down Belmont Road, 
 comes around the corner, grabs the 
 posters off the fence, sort of half 
 hides behind a a pole at one point, and 
 then scurryies back up Belmont Road, 
 sort of ducking under the under the 
 wall. And yeah, I 
 it sounds crazy. I have the video. see 
 this. Uh, I think it's fairly sensible 
 because I've, you know, I can't identify 
 who's in the video. I'm not sure anyone 
 else can. That's the whole point of him 
 covering his face. So, I think I'm I'm 
 quite legit in publishing this. 
 So, yeah. Well, 
 I have the weirdest neighbors, but I 
 mean, 10 out of 10 for entertainment. 
 Who'd have expected him to plan a 
 midnight raid to take a poster off my 
 gate? I mean, that's just Well, wow. 
 Wow.