Electronics

The Clock Of Life

/ masher / 8 Comments

At one of a our nerdy amateur radio rallies a couple of months back, a mate of mine bought a box of old crystals.

Of course, I am not talking about a bowl of crystals used for aligning your chakra, or shit like that, but quartz crystals that have been cut and shaped, such that they will resonate at a particular frequency when a voltage is applied to them, making them useful for making accurate oscillators for clocks and watches… and radio transmitters, of course.

My mate was bemused when he found a crystal in the box that was stamped with his date of birth… or near enough, anyway.

He also found one that had my birthday (month and year) stamped into it and he sent it to me.

And so, I made a simple oscillator with it. That’s it in the above picture.  The yellow LED is set to flash at 1.2Hz. That’s equal to 72 times a minute – the average human heart rate at rest.

It’s battery powered and I’ve added a trickle charger to it,  using two small solar panels (the black rectangles behind the battery), so, in theory, it should be able to just sit on my windowsill, flashing away almost indefinitely (well, within reason).

The idea is to see which gives up first… the crystal or my heart… bearing in mind they are the same age.

Rather like Liz Truss and the lettuce, it’s just a bit of fun.

Email Overload

/ masher / 4 Comments

You know when you order something from Amazon or eBay (and many other sellers, it has to be said), you generally receive an email confirming your order.

A while later you might get another email saying that your order has been dispatched.

And when you eventually receive your order, you might get a final email confirming that it has been delivered to you.

Well, a couple of weeks back, I ordered some items from AliExpress… because they are so bloody cheap compared to the UK.

I ordered four items. If you must know:  a pack of MOSFETs; An Arduino Uno board; some blue LEDs and a multi-ganged 12-way switch.

Once I had completed the order – four items but in one order, paid with one payment – I received a confirmation email.
For each item. So I received four emails.

This was followed a short while later with another email saying “Order ready to ship”. For each item.  So, another four emails.

An hour later, yet another email: “Order shipped”.
For each item.
Four more emails.

This was followed up the next day with another four emails: “Package in transit”.

A few days later, another four: “In your country/region”.

Then: “Cleared Customs”.

“Out for delivery”.

And then finally “Delivered”.

Except, it wasn’t the final one.  Another four arrived a couple of days later: “Awaiting confirmation”.  This means they are waiting for me to go on to the website and confirm that I have received my order.  So I did.

That then generated four more emails: “How did it go?”  Basically asking me to go online and review how well the ordering process worked.   All in all, I received 40 emails regarding the four items that I ordered.

I was tempted to actually do the review, complaining that they sent too many emails.

But I thought I might have to do it four times.

 

Alarming Progress

/ masher / 8 Comments

A couple of years ago, I decided I should get an alarm for the garage.  It’s always had one, but it’s not particularly good and now that I have en expensive motorcycle and a not-so-expensive motorcycle and several hundred pounds worth of power tools, I thought maybe it was time to upgrade.

However, I wanted the alarm to have several additional features that are just not available on commercial alarm systems, and so I decided to build my own.

As I say, it’s been a couple of years now since I started this project and it is still sitting on the bench. That’s it in the photo.

Unfortunately, it’s been one of those projects that has gone on and off my back burner quite a lot, and the main reason for that has been the programming side of things – I’m rubbish at it.

It’s also one of those projects that has suffered extensive scope creep… everytime I think I’ve reached a point where I’m happy with it, I find myself thinking “Hmmm… it would be good if it did so and so, as well”, and it then spends another few weeks on the bench while I fail miserably to get the amended programming to work and then lose interest in it.

The most recent example of this is where I decided that the alarm sounder side of things should be changed.  The siren is incredibly loud and the flashing lights are very bright and (trying to imagine every scenario), I thought the neighbours probably wouldn’t appreciate that going on for twenty minutes in the middle of the night, if we were away.  I came up with a solution, but again, my programming skills let me down and so the project headed for it’s home on the back burner. Again.

A chap I was talking to on the radio turned out to be very good at this sort of thing and offered to help, and so one evening last week, over Google Meet, I shared my code with him.  It took him about ten minutes to figure it out – I was doing the right thing, but I was putting the code in the wrong place… damn nested If Then loops!

And so, it is now definitely finished (probably).  I just need tofinish building it, stick it in a box and fit it in the garage.

And then my garage will be protected by an alarm that:

  • Has multiple and adjustable length keypad entry codes
  • Different entry times depending on which entrance is used to access the garage
  • Single button-press alarm setting
  • Auto alarm arming (should you forget to set it when leaving the garage it will arm itself, providing a set of criteria have been met)
  • An incredibly loud siren that sounds in conjuction with some flashing floodlights inside the garage, but which turns off after a set period of time, leaving the floodlights flashing until the whole system resets itself after another set period.
  • A set of floodlights that flash as per above, but can also be switched on and off manually by the keypad when the system is unarmed, to provide a good working light when tinkering with motorbikes, etc.
  • Control of the normal garage lights – ie, the lights come on when the door is opened and go off again when the door is closed and the system is armed (either manually or automatically)
  • Battery backup if the mains supply fails.

So now I need to crack on and get it built (in truth, a lot of it is already done).

But it’s carrently on that back burner again, whilst I think of shit to write in this here blog.

For Sale: One Back Burner – Heavily Used

/ masher / 7 Comments

As you both know, I have several hobbies that take up much of my spare time.

The most prolific of these is electronics, which I have been playing around with since I was 14.

Over the years, I have built many projects, most of which have ended up being dismantled or discarded once I’d lost interest in them, but also some that are still in use regularly to this day.

Nowadays though, it takes me longer to build things, because I simply don’t seem to have as much spare time as I used to.  And, I’ll often find, that halfway through building a project, something else will grab my attention. Project A will then go on the back-burner whilst I start on Project B.

I am in that situation right now: Project A – a large project that I have been working on for a couple of years (it started life as my Lockdown Project, back when we had the plague) has spent more time on the back burner than on the front. And it is sitting there right now, gently simmering whilst I work on Project B.  Occasionally, I will come back to it and give it a bit of a stir, but for the moment, all my time and energy is focussed on completing Project B.

Or, at least, it was. Because the components for Project C arrived in the post yesterday and I am quite excited and keen to get started on that one.  Of course, I should put it to one side and wait until I have finished Projects A & B, but I know that won’t happen… Project B will be squeezed onto the back burner, alongside Project A, whilst I put all my focus into Project C.

Having a back burner really isn’t helping.

 

Eye In The Sky

/ masher / 4 Comments

A couple of weeks ago, one night, as I emerged from the woods whilst walking the dog, I saw a flashing green light in the sky.

“Hmmm, what’s that?” I wondered. My only guess was that it might be a drone.

It wasn’t moving and it was difficult to gauge it’s height.

It appeared to be totally silent.

Suddenly, it darted to the right, very fast, and hovered high over some houses about about 100 metres away. It stayed there for a minute or so then darted back to it’s original position.

By now, I was at the end of the path and was much closer to it, but I still couldn’t make out what it was.  Maybe it was a UFO?

Well, it was an object and it was flying and I was unable to identify it, so I suppose it was.

I put the dog on the lead and we crossed the road and headed home and I noticed that the green light was following me… from a distance.

It’s about a ten minute walk home: across the main road; through a cul-de-sac with an alleyway at the end of it, then across a small green and into my road.

At all times, the green light followed.

As we got to my road, it whizzed around so that it was in front of me and it’s height lowered, such that it was hovering about twenty feet above the houses.  Now that we were away from the traffic noise and it was a bit lower, I knew that it definitely was a drone, as I could hear the tell-tale whine of it’s little motors.

I stopped and looked up at it.

It stopped and looked down at me.

I raised my arm and fired a shot at it from my pretend gun.

It didn’t fall out of the sky.  Or even pretend to.

Hovering high above my back garden, it watched as I went into the house. It stayed there for about thirty seconds as I looked at it through the window and then it disappeared into the night.

It was slightly unnerving.

Kindle shopping

/ masher / 8 Comments

As we will soon be taking a bit of a holiday, it occurred to me that I should charge my Kindle.

I love reading novels  and used to be a prolific reader back in the day: I would read at lunchtime whilst at work and I would always read for an hour in bed, before going to sleep.  I would easily average a novel a week.

But, as I got older and circumstances changed and other interests came to the fore, I found less and less time for reading.  Nowadays, when I go to bed, there is no chance of getting any reading done: I’m usually asleep before my head hits the pillow.

So, reading has become something that I only do nowadays, whilst on holiday.

It had a resurgence some years back when I was contracting and working away from home a lot and it was whilst mooching around the big fuck-off Tesco up in Lichfield (or Stafford – can’t remember exactly), that I espied the Amazon Kindle Gen 3. At 150 quid, it was a bit expensive, but I figured it would soon pay for itself and so I bought one.

Pay for itself, it did!  And it revolutionised my reading habits, as I was now able to carry dozens of books around with me and dip in and out of them as I wished. Coupled with the built-in SIM card, I could even download books and newspapers etc. whilst on the move.

It’s fairly safe to say that I love my Kindle.. even though again, it only really comes out at holiday time nowadays.

And so, I went to take it off the shelf where it always sits and put it on charge.

Except… it’s not on the shelf.

I had a bit of a move around (tidy up) a couple of months back and must have put it somewhere else.

Gawd knows where.  I have searched every inch and cranny. Twice. There’s no sign of it anywhere.

I have proved to myself many times in the past, that the best way for me to find a lost item, is to buy a new one – the lost one will magically reappear shortly after.  And so, I am now the proud owner of the 11th generation Kindle: the Paperwhite.

Lovely device: smaller and lighter than my old one, with several improvements, twice as much memory and a slightly bigger screen.

And so, to put some books on there, in readiness. All my old content immediately transferred on to it as soon as I registered it on the Amazon website, but I wanted some new stuff.

Every so often, I’ll try a dip into the classics… usually with marginal success.  Catcher In The Rye didn’t manage to capture my attention and To Kill A Mockingbird bored me such that I only managed about a third of it. But I’ve enjoyed a bit of Oscar Wilde (The Importance Of Being Ernest is, of course, my favourite Wildean tale) and I’ve decided that I should dip my toe into George Orwell’s canon, with 1984 and Animal Farm  being the two most obvious to have a go at. And when you can download his complete works onto the Kindle for just 99p, it’d be daft not to give it a try.

But Science Fiction has always been my go-to genre and I have read most, if not all of the works from some of the most prominent authors: Clarke; Asimov, Bear, Niven.. etc.  but I have also found a wealth of lesser-knowns inhabiting Amazon’s Sci-Fi section, and some of them are writing some really good stuff which can be bought relatively cheaply.

Whilst Sci-fi is my preferred read, it is a sub-section of that genre that I really enjoy reading: Time Travel.  Traveling through time and all the quirky paradoxes that come with it, always leave an impression on me… if it has been well-written.

Many, many years ago (in a galaxy far, far away – actually, it was just the other side of town, but I digress), I read one such story. I still lived with my parents at the time, in our first house, so I guess it was about forty years ago.   I remember finishing it and thinking what a brilliant and clever story it was.  For some reason, about five years ago, it popped into my head and I fancied reading it again, but I couldn’t remember the title or the author. And after 35 years, I couldn’t really remember much of the plot.  But I did remember bits of it. Sadly, typing “Cambridge Scientists Time Travel Particles” into Google and other search engines, threw up nothing.  But then yesterday, whilst looking through Amazon’s list of books in the Sci-Fi Time Travel genre, it suddenly jumped out at me! How excited was I?

Very.

Timescape, by Gregory Benford, if you’re interested.

It’s now on the new Kindle, ready to be devoured as soon as Holiday Mode is activated next week.

I’ll let you know if I enjoy it as much the second time round.

I’ll also let you know if the old Kindle ever turns up!

 

Getting my money’s worth.

/ masher / 8 Comments

As mentioned last week, I have added some extra sockets into the study.

Yesterday, I finally got round to actually fitting the faceplates.

Once everything was wired up, I switched the circuit breaker back on, to restore power. Nothing went bang (always a good sign), but when I plugged in my mains tester, it showed an earthing fault.

Bugger.

I removed a couple of faceplates and checked the wiring.

As far as I could see, there was nothing wrong, but still my trusty mains tester told me there was a fault.

I plugged it into another socket in a different room and got the same result, so obviously it was the tester that was faulty.

It was one that I’d made way back, from a circuit in an electronics magazine. I’m thinking somewhere around 1980 to 1982 and I think it cost less than a fiver to build.

As is usual with anything like this, I immediately reached for a screwdriver, opened it up and had a poke around inside.

It was a very simple circuit and it didn’t take long to diagnose that it was the neon bulb that had stopped working. Unusual, but quick and cheap to fix.

However, I had no suitable neon lamps in my components box and so I started searching online.

And whilst I was doing so, a voice popped into my head: “For fucks sake, you’ve had that one for years, just buy a new one, Masher, just buy a new one! They’re not expensive.”

And so, fifteen quid  and twenty-four hours later, I found myself in possession of a fancy new one.

I’ve checked all my sockets and they’re all good. Of course.

If this new tester lasts as long as my cheap homemade one, I’ll be happy.

But, my desire to fix things never goes away and I have just ordered some new neon lamps so I can get my old tester back on it’s feet. Seems daft not to, when a new lamp only costs 35p.

Always good to have a backup, anyway.

Out and about

/ masher / 7 Comments

Today I went to St Neots, in Cambridgeshire.

And wandered around a damp field.

Full of damp men.

Looking at a load of old, damp, radio-related tat.

And had a great time… as did we all, I think.

It’s the first radio rally I have been to in nearly two years and it was good to catch up with some like-minded nerds, who I haven’t seen in a while.

And I grabbed a couple of bargains too, which pleased me greatly.

It looks like the rally calendar is starting to get back to normal.

Hopefully, the next one will be just as enjoyable.

And not as damp.

Rip Off Britain

/ masher / 10 Comments

Many years ago, I had a Psion Series 3 handheld… remember them?

I loved anything gadgety and the Series 3 fitted the bill nicely.

When it was superceded by the Series 3A, I immediately went out and bought one, even though it wasn’t that much of an upgrade.

As I remember, it cost about three hundred quid at the time.

And I was amazed, when Mrs M and I went on a shopping trip to New York just a few weeks later, to see the very same device being sold for almost half the price!

I wouldn’t have minded so much, but the damn thing was designed and built in Britain, so how can it be so much cheaper in a different country?

Fast forward to today: I was mooching through some ham radio videos on YouTube, and in one of them, someone – an American chap – showed how to build an interesting project using a Raspberry Pi, and in his video, he showed how all the parts could be sourced from Amazon. He even showed the actual Amazon pages, so one could be sure of buying the right parts.

Intrigued, I noted them all down and then went to the UK Amazon site. I then found all the parts and totalled up the price.

It worked out to be fifty quid more than what this guy paid for it in America!

The Raspberry PI itself made up over half of that difference: 64 pounds in the UK, but only 37 in the US… 27 quid cheaper!

Again, the Pi was designed in Britain.

It is a hugely successful British product.

And whilst some are made in China and Japan, the bulk of the forty million or so that have so far been sold around the world, have been made in the UK.

So why the hell are we that live in the UK having to pay so much more?

Let there be light… after a short while

/ masher / 9 Comments

A few weeks back, half a dozen of us took a ride up to a café, on the A10, near Royston.

It’s a popular haunt for biker’s and – on a sunny Sunday morning – it was pretty busy, even with the Covid restrictions meaning that we all had to eat outside on the limited number of benches available.

But we did.  And it was good.  And then we left.

Except that we didn’t. Because my bike refused to start.

CLICK, it went. CLICK.

I had to suffer the ignomy of being pushed, in order to do a bump start, in front of dozens of fellow bikers.

This is only the second time this has happened in the nine years I have owned the bike, but even still…

Doing some research into this problem, I learned that it’s a well-known (not to me it wasn’t!) issue, within the Triumph Bonneville community, which is generally referred to as “The Dreaded Click”.

One suggestion I found, was to fit a switch on the headlights to save on current draw when starting (I think many modern bikes aren’t fitted with an on/off switch nowadays, as having the headlight on permanently is seen as a safety feature, so they have removed the ability to turn it off). I saw several examples where people had fitted a switch onto the headlight housing.  There was no way, I was going to ruin my beautifully chromed headlight housing, by drilling a hole in it. There is a headlight cut-out relay fitted to most bikes nowadays, for this very reason, but it seems they don’t always work.

So, instead, I made a small timer board. That’s it in the picture at the top of this post. Wrapped in self-amalgamating tape to keep it dry and also to prevent any shorts against the metalwork, this fits easily inside the headlight housing and keeps the headlights off for about fifteen seconds from when the ignition is switched on.

The circuit is simple and I built it onto a small scrap of stripboard that I had lying around. The rest of the components were from my bits box, apart from the relay. I decided to by an automotive relay as they are water-resistant – a fiver from my local auto parts store. Also, they can handle higher current than the piddly little relays I have to hand – I measured the headlight current draw at 4A.

The positive connection to the headlight main beam was cut and put in series with the normally closed contacts on the relay. I decided to do it that way, so that the headlight would have power, should the circuit fail for any reason.

Power for the circuit was taken from the sidelight, using a couple of Scotchlok connectors to tap into the wiring.

Total cost?  Well, I had most of the parts, but I reckon about six quid.

On a ride up to Jack’s Hill last Sunday, it worked perfectly.

I thought I’d post the idea here for anyone else having the same issue.

Of course, I can’t be held responsible if you bodge it and blow all the fuses on your bike!

Still annoyed

/ masher / 6 Comments
You know when you build a ringer circuit to drive the bells on an old rotary telephone powered by an Arduino, and you design the veroboard layout, optimising it to get the board as small as possible so it will fit in the phone, and then you spend an hour or so, carefully soldering the components into place and when you’ve finished, you sit back and admire your handiwork before you then connect it to a power supply and check that it works OK, but it doesn’t, because you realise almost immediately that you got the Gate and the Drain the wrong way round on the MOSFETS, but when you try to get them out, you can’t because the board is too densely packed underneath and even with a de-solder pump and some solder wick you can’t get the damn things out and then the tracks start to lift because you applied too much heat for much too long, so you realise that you are now just going to have to throw it away and start again?
You know when you do that?
It’s bloody annoying, isn’t it?

Project Phoenix

/ masher / 7 Comments

I was gifted a lovely little radio a while back – a Yaesu FT-270R.

It’s an old 2m model, dating back to the late eighties, I’m guessing.  As such, it lacks CTCSS capability, which limits its use somewhat.

However, there is a space inside to fit a FTS-8 subtone encoder board. And so I thought I’d fit one of these and give it a new lease of life.

Sadly though, the FTS-8 board is no longer available and secondhand ones command a hefty price tag.

What to do? Well, make one of course!

I found an elegant design on the web and built it onto a piece of veroboard. Plugging it into the radio, changed some of the available functions, so the radio obviously detected the board.

It allowed me to choose the subtone from the front panel. Excellent.

But it didn’t work.  Checking  the output with my scope, the tone just wasn’t there… or rather, it wasn’t what it should have been.

I spent ages fiddling with it, but ultimately could find nothing wrong.

And so I passed it onto Dave, who – being a clever bugger – worked out pretty quickly that the board I had built actually worked perfectly. Unfortunately, the radio didn’t. It was giving out the wrong signals to the board.

This wasn’t something that could be easily fixed – possibly a microprocessor issue. And so, I figured a workaround, that would allow the tone to be selected manually, using a combination of switches to produce the binary equivalent of the hexadecimal value that the board was looking for in the tone lookup table.

This worked perfectly and when I tested it, I was successfully able to open several different repeaters, all using different subtones.

And then I found a bug, where the tone would only change after five minutes and not whenever the PTT was keyed.  This looked to be a fault with the MCLR on the PIC… possibly damaged by putting in 7.6 volts from the radio (datasheet states that Vpp shouldn’t exceed Vcc). Not having another chip available, I made a slight mod and fitted a miniature relay, which only allowed the board to be powered when the PTT was depressed.  This seemed to work nicely and I was able to switch tones easily and on-the-fly.

So, I put a call out on a repeater. “Your audio is awful!”, I was told.   I replaced the mic ( a new one from ebay cost fifty quid! Yes, fifty quid for a 30 yr old mic!) with an old YM-47 from an FT-290 and it worked perfectly… once I had figured out the differing wiring scheme.

And so, after many weeks of working on it, on and off, it is ready to be put to use.

Not that I need another radio at the moment, so a friend is going to borrow it.

Many times I nearly gave up on it and was going to throw it away. But, I had invested a lot of time and a reasonable amount of money on it and so I wanted to see it through.

I’m pleased that it is finally finished and working… because that means I can now move onto my next project 🙂