Thrown into it.

I was tasked to provide a door interlock system. The system comprises 3 doors and an airlock; plus some rules.

Doors 1 is a 230V shutter to outside; door 2 is a 415V shutter to a clean area. Door 3 is a fire door into a sterile room.

  • When door 1 is open neither doors 2 or 3 may open.
  • When doors 2 or 3 are open door 1 must not be allowed to be raised.
  • A green break glass override must be provided.
  • Safety beams are required on door 1.
  • Door 1 must operate on a 5 minute timer so if the door is left open; clear of obstruction AND the area is unoccupied then it must close fully.

I achieved this using a programmable logic controller (PLC) and using 11 ladder networks and some cunning logic the above was all achieved in 2 days including all installation. It was important that the system was fitted as cleanly as possible with a minimum of containment and so I managed to rod most of the wiring down the backs of the walls as they were plasterboard over stud.

It took 8 inputs and 4 outputs to control the system.

  1. A 12V normally low input from a push button station (up button)
  2. A 12V normally low input from a push button station (down button)
  3. A 12V normally high input from a sensor telling the system shutter 2 is in the lowered position.
  4. A 12V normally high input from a sensor taking the system the clean room door is closed.
  5. A 12V normally high input from the safety beam system on shutter 1.
  6. A 12V normally high input to indicate that shutter 1 is in the lowered position.
  7. A 12V normally high input from the green safety release buttons; wired in series.
  8. A PIR to detect occupancy of the area (this signal rising to 12V starts a 5 minute timer to close the shutter; this timer is reset if either door button is pressed, if occupancy is again satisfied or if the beams are interrupted).

Two flags are created inside the system; safe to open and safe to close – these pertain to shutter 1. If at any point the green emergency release buttons are pressed then all sensors are set to high and the system is cleared to operate all doors manually only. The automatic close no longer functions when this situation occurs.

  1. Output 1 is the relay for the door to raise.
  2. Output 2 is the relay for the door to lower.
  3. Output 3 controls the mag-lock keeping the clean room sealed.
  4. Output 4 controls a relay breaking the signal from the up button of Shutter 3 to the controller.

I just wish I could have got raise and lower buttons quickly enough, but instead I got red and green and I’ve since labelled them using my P-Touch and clear label tape. Green takes you to a safer situation (door open) whilst red takes you to a more dangerous condition (door closed) and so it does satisfy best practice.

I might add that this is also why “on” for a circuit breaker is red whilst off is green.

Finally the big mushroom is the motor panic button. This overrides all the electronic systems and is physically connected to the motor on shutter 1. It is a full kill switch and kills power to the motor should interlocks or systems fail.

I know for you guys my work isn’t always that interesting; but this job has fascinated me as I love doing PLC work; after all what are fire alarms except for lots of logic gates.

The Galaxy Note 20. The first few days.

I didn’t make it totally obvious but I got a new phone on Tuesday. A Samsung Galaxy Note 20 Ultra.

Initial reactions?

The most obvious change from the Note 10 is the total 180 flip of the design. The buttons move from the left hand side of the chassis across to the right hand side. It didn’t take much getting used to and actually feels more natural. They aren’t as easy to catch for a start.

The s-pen moving to the left on the other hand is a really awkward change. As a right handed person I want to grab my pen with my right hand, but I have to twist awkwardly to do this. I’m sure I’ll adapt, but bad Samsung. Lefties will be loving it though.

One UI 2.5 is sweet. I never had much love for Samsung’s old UI (Touchwiz) but I adore how smooth One UI is, and with 2.5 we gain some really nice improvements. Samsung have stopped loading it down with useless clutter and now make meaningful changes to how it works.

Wireless DeX seems interesting. I’ve played with it a couple of times (I do use DeX a hell of a lot) and whilst it’s not great on our TV as the lag is about half a second (a 2014 Samsung model) it works much better on my Microsoft wireless display adaptor and has hardly any delay. I think it’ll come in most useful for my presentations. If I ever do any again with the current situation!

Now let’s get to the camera.

With COVID I’m not traveling and photographing in the same way so I’ve not really had chance to do much with the camera, but it does seem better than the old one. I did take a photo of woods yesterday with the 108mp mode turned on and it was “interesting”. From a distance the level of detail looks really good, but not amazing.

Zoomed in however the software has turned it into something slightly trippy and as if Google Dream has had a bit of influence.

I’m going to have a few more tries with the 108mp mode but I’m not exactly blown away with it.

On the other hand the general photography has yielded good results in both good and poor light.

Let me know in the comments your thoughts.

The final issue that a few people have noticed is battery life. I don’t have many anxieties myself, but I am a very battery anxious person. I keep my life on my phone and if the battery runs low I panic.

That said, the Note 20 even with the Exynos processor isn’t faring too badly. I know you could say we don’t get a good a deal in Europe as the USA gets, but we do get a base storage of 256 gig in place of the 128 base the USA gets.

The phone definitely runs warmer, and on my initial setup the phone wouldn’t charge because the processor was fully throttled up – the charger merely maintained the battery percentage – but other than that I haven’t really noticed much difference between the Note 10 and Note 20 in real world use.

So final thoughts?

Well it’s a nice little upgrade, and certainly with the cameras feels less iterative, but if you don’t care for the cameras and you like your note 10, stay where you are.

My Carry

I’ve often seen people sharing “what’s in my bag” posts when it comes to tech. These people often traipse around carrying a huge backpack with dozens and dozens of cables, bricks, chargers, dongles. Well I’m the opposite. I’m a pocket guy and I have an absolute bare minimum of kit. I like everything the have multiple uses and if it doesn’t fulfill my requirements precisely I’m always seeking a better version. So here we go… My pocket carry.

1. Phone

It’s a Samsung Galaxy Note 10+. The rather nice shiny chromatic one.

It’s main selling point for me is the stylus – but more importantly the fact it’s a Bluetooth stylus with accelerometer and allows remote control over the phone to an extent. I have used it for presentations and it feels great holding the button in and flicking left to go to the previous slide. It’s also usable as a remote camera shutter.

The camera is very capable and I no longer use my other cameras because of this.

Also, with an almost 7″ screen it’s a great media consumption device and because the screen is AMOLED it’s daylight readable and usable.

I’m also a huge fan of Samsung Pay. It allows me to leave my wallet at home. I’d love the ability to log into a cash machine with it and dispense cash, but alas that’s not a thing yet.

2. Headphones

Media consumption is also improved with my earphones – the Samsung Galaxy Buds. Great sounding. Good battery life. And I can charge them using the same cable and charger combination as the phone itself, or for a top up I can use the reverse wireless charging feature in the phone.

3. The Watch

I also have a watch to go with the setup. It’s good as a notification tool, but also has the added bonus that you can use it as a remote control for the camera too (with viewfinder).

The Watch I have is a Galaxy Watch LTE. It’s the smaller 42mm version as I just find them a little more manageable. I’ve had a 46mm version and it was also nice, but the 42mm just feels the right size to me.

4. Keeping it running

I have a number of solutions for keeping all this stuff working.

First I use a folding charger. It’s made by Mu and answers all my grief about British plugs.

Unfortunately development on these seems to have stalled which means the USB C version never appeared. Not to worry though as my next item depends on a regular USB A port.

The cable I keep with me is a bracelet in disguise. It’s a beautiful invention and looks just like a simple leather band bracelet, until you separate it at which point it turns into a USB A-USB C cable. The one I have is a good enough spec to do DeX on PC.

Finally, for longer journeys I have a battery brick, or battery case, or a combination of both for even longer journeys.

Also in my occasional carry is a Surface Wireless Display adaptor and pocket projector. A small gadget which allows you to project wirelessly and the projector to plug it into.

These all charge using usb C so I can keep a battery case charged rather than having to tether to a socket using an obscenely short usb cable.

For now this all works for me, although I’m sure it’ll constantly evolve. Note though that just 2 years ago I was a bag person.

One port to rule them all?

So after purchasing my new tablet (Tab S3 in case you missed it) I have now headed another step down the road to being totally USB C sufficient.

USB C is the new de-facto charging standard which if rumours are correct might even be coming to Apple devices (yes, I know, Apple using a global standard rather than making their own) but then Apple did adopt Qi charging so perhaps they’ve realised that being exclusive is hurting customers?

It’s great to see USB C on my phone, tablet, Nintendo Switch, and one of my 360 cameras.

So I suppose the next step is to now get the other end of the cable to be USB C so the charger and power bricks support the standard?

Well here’s my new power brick…

Note the single USB C socket on the end. This can be used to both charge the brick, and to charge other devices (as is the nature of USB C), and amusingly, when the device you plug into this brick recognises it, it offers the choice to charge the phone from the brick, or charge the brick from the phone. Quaint.

I think we’re a few years away from the one port to rule them all, but with its flexibility, ability to send video, data and power the USB C port might be the answer.

Of new tablets and stuff…

So, on Friday I saw a Galaxy Tab S3 in CeX (a chain of tech second hand shops). It was over £100 less than the full price in Currys and was actually in A1 condition. Not the 4G variant, but I can always tether to satisfy that problem.

I decided to take the plunge as my Lenovo Yogabook really wasn’t working for me. Funky as it is to look at, the Yogabook running Android Nougat is actually pretty piss poor. No window mode support, just split screen; and to add insult to injury the OS is buggy and has been abandoned by Lenovo so will never be fixed or updated. The styles implementation is lacklustre to say the least and borders on gimmicky. I hardly ever found myself grabbing the stylus as it was so bad!

Enter the Tab S3 – a very capable tablet created by Samsung who, whilst I won’t say are perfect, are much better at keeping their flagship devices running for a somewhat longer time with updates.

The Yogabook was traded in and the money used to buy a keyboard case (from Argos as CeX didn’t have any in).

Yes. It’s so much better!

Ditch the phone

It’s amazing how we all sit there with what in essence is a pocket computer in our pockets (think Blondie’s song “Picture this”).

We constantly have to check on our social world, just in case we have missed something; and yet the real world around us passes is by.

Getting a 4G smart watch made me think of trying something the other night though – ditch the phone, trust the watch.

I still have a means of communication, but all the apps and social media is gone. The notifications pushed from my phone stop so I just get basic calendar stuff, and I’ve still got a very basic browser and Google Assistant should I need to check soberin something.

Facebook, Instagram etc. are all history.

There was only one downside – no camera; however this was no biggie for feeling connected to the world.

I think I’ll do it more!

40 years!

The astronomical society I’m a member of has just celebrated its 40th Birthday.

It’s quite amazing to think that I’ve been a member on and off for 35 of those years! I first attended in 1982 and joined in 1983.

I’ve watched us go from a tiny society of about 15 people, all the way up to a charity with assets and property with substantial value.

It’s not been easy along the way, and the times I served on the committee are testament to that – many nights sat arguing my case over trivial matters.

Anyhow, we have made it to 40! Here’s to many more happy years, Mexborough & Swinton Astronomical Society!