A Driving Instructor's Blog

Computers & Tech

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DoogleBooks LCD drawing and writing padEver since I became an instructor I’ve managed to get through a lot of notebooks. Anyone who does this job will know that you have to sketch a lot of things when you’re explaining stuff to pupils.

I started off buying notepads, but realised that was quite expensive – especially if you wanted the larger sizes. Then I turned to making my own, by ring-binding punched copier paper and using that. I discovered that normal two- or four-hole punching was no good, because the sheets could easily get torn with all the handling and jolting they get in the car, so I turned to spiral binding. That served me well for many years – but I was starting to feel my conscience nagging me over the amount of paper I was getting through.

A few years ago now, I tried using my laptop. It’s a Surface Book Pro with a detachable screen so it can be used as a tablet. With a simple sketching app, it was fine – but there was still the hassle of getting it out, booting up, then detaching the screen, then reattaching it and powering down when I’d finished. There’s no way I wanted my Surface loose in the car while it was moving and quite frankly – in some of the places you have to cover – waving a two and a half grand laptop around is not the smartest thing you can do.

Then I had one of my thoughts. It occurred to me that there must be something out there that could just be used as a drawing board, but which didn’t involve dirty rags covered in black marker from the dry-wipe boards some people use. That was when I came across LCD drawing pads. At the time I first tried them, they were usually 6 inch or 9 inch screens. I found a 10 inch one and it worked great. I still have it, in fact. But a couple of years ago, while still looking for something better, I came across DoogleBooks.

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The main attraction at the time was its size – it’s a 12 inch screen, so about the size of a piece of A4 paper. It also boasted an erase function (you can erase parts of your diagram with an eraser on the stylus) and a bright screen – my original cheap import was quite faint, though still perfectly usable. It comes with a padded protective case and a separate eraser, a lanyard for the stylus, and some spare tips, and a few bits and pieces for kids rather than adults (and which I never did figure out what they were for).

It is powered by – believe it or not – a standard watch battery, which lasts ages (I’m still on the original after nearly two years). That’s because the device is not illuminated in any way, so doesn’t draw much power.

You ‘turn it on’ with a very small switch on the back, though this is a ‘lock’ function rather than a power button as far as I can tell. The stylus clips neatly into the frame (come to think of it, it was because the clip on the cheap one I bought snapped which got me looking again) and has a nice long lanyard so you don’t lose it.

Once powered/unlocked you just write or draw whatever you want. The width of the stroke is governed by pressure and angle of the stylus nib, so you can get thin lines or thicker ones as needed. If you want to start again, you just press the button on the left in the picture above with the trash can symbol twice, and the screen is cleared. The double-press is a safety feature so you don’t erase by mistake – see the next bit for why.

If you make a minor mistake, you can erase just part of whatever you’ve drawn or written. Press the other button until the red LED comes on, then use either the small rubber eraser on the other end of the stylus, or the larger rectangular one which is supplied – just like you would with pencil on paper. Once you’ve erased whatever you want, press that button again until the LED goes out and you’re back in drawing mode. Due to the proximity of the buttons, you can see why complete erase needs two presses. This selective erase does work, but be aware it does leave slight smudges behind – again, like you’d get with a pencil on paper.

It is not a computer. Anything you write or draw exists only on the screen for as long as it’s there. You cannot transfer it to a computer, since it is not a digital image – it is exactly the same as a pen or pencil drawing. If you write ‘CAT’, that’s just some shapes and lines – the tablet doesn’t know what you’ve written. If you erase something by mistake, it’s gone forever – there’s no undo feature. If you want to save anything, you can take a picture – pupils often take a shot of things I draw so they can look at them later, just like they used to when I drew on paper.

The device I used previously had a much fainter screen, and this meant that on evening lessons it could be difficult to see what you’d drawn. As I explained earlier, there are no backlights on these things, and they are literally the same as pen and paper – you can’t see drawings made using those in the dark, either. However, DoogleBooks has a much brighter screen contrast and you can see your drawings clearly with the interior light on. The photo above was taken at dusk with no lighting, and that’s the contrast you get.

It’s been one of the best things I’ve bought in a long while. I actually have a spare in reserve, which came about because the original Amazon order never arrived, and the owner of the British company which sells them sent out a replacement. Several weeks later, the other one arrived – God knows where it had been – and when I offered to return it the owner said to keep it as a gesture of goodwill!

They now do several different models, mainly aimed at kids, with different screen colours. And whereas the only frame colour available when I bought mine was cyan (which is actually my least favourite colour in the whole world), they now do them in a range of colours. Just be careful to choose the ‘’partial erasure’ one unless you want to save a couple of quid and lose a bit of functionality.

It’s infinitely better than using a dry wipe board. There’s no mess, and it is ready to use the instant you take it out of its case. Unlike dry wipe systems, when you erase, you erase – no ink getting stuck in scratches, which always happens with dry wipe markers. And the stylus lasts oodles longer than a marker pen. And there’s no thick pads of drawings to dispose of when you’ve filled up a notepad.

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PayPal Here card readerThis article was originally written in 2015. Prior to PayPal Here, I had used iZettle, but I had an unfortunate experience with them.

PayPal bought iZettle a few years ago. The current situation in the UK is a little confusing. In the USA, you can buy an updated version of the PayPal Here machine I am currently using. In the UK right now, PayPal directs you straight to iZettle readers.

Note that the following article is specifically aimed at card readers per se, and not with the issues I experienced with iZettle when it was an independent company.

Since 2015, I have taken close to £80,000 in card payments through PayPal Here (it’d be closer to £100,000 if not for COVID). As time has gone by, the number of people paying me by card has increased dramatically, and right now well over 90% of pupils pay that way. The rest still use cash – and very occasionally,  someone will hand over up to £700 in notes to pay for a block of lessons). One or two use bank transfer.

I do not take cheques, and haven’t done since 2015 – if someone can write a cheque, they have a bank card I can read in the car. That means I get paid immediately, and there’s no risk of a bouncing piece of paper. These days, the only real reason for anyone to want to use a cheque is to defer payment, and I don’t play that game anymore (it’s too risky). The other problem with cheques is that I have to go to the bank to gain credit from them – which is also true of cash if I accrue too much – or I have to piss around with photographs and smartphone apps, which I also don’t want to do.

The PayPal Here card reader can carry out transactions via contactless, PIN, and swipe (though swipe is not necessary in the UK). All you need to do is buy the card reader outright, download the app, connect the two through Bluetooth, and you’re set to go. With PayPal, the money is in your account within  seconds.

Although attitudes have improved since 2015, there are still instructors who – for various reasons often associated with avoiding HMRC scrutiny – are against taking card payments, prefer cash, and who then try to justify their position with lies and misinformation based on their own ulterior motives.

For me, being able to take card payments impresses the majority of pupils. It’s like you are performing a magic trick in front of them, and they marvel at the machine when they use it. Taking card payments also ensures you being paid for the lesson you just gave. I mean, let’s face it – the only two business-related things a decent and respectable ADI needs to worry about when dealing with the financial side of their services is happy pupils, and being paid on time.

BACS is better

BACS is a viable way of taking money, but it isn’t ‘better’. It relies on the pupil ‘remembering’ to do it, and often needs at least one chase to make sure it happens. If it doesn’t, you’re then into either more chasing, or cancelling the lesson if you insist on advance payment (so you lose money anyway).

I recently (June 2021) gave refresher training to someone who passed with me before the pandemic. On one lesson, he paid me in cash (which is now in my wallet, and will need a bank visit at some point). On the second, he wanted to pay by BACS, so I gave him my bank details via text message while he was still in the car (minor hassle #1). One day later the money had not arrived, so I texted him (minor hassle #2). He replied that he had sent it (the money miraculously appeared while I was replying (minor hassle #3) that he must not have ‘fast transfer’ on his account). I immediately texted him that I had got it (minor hassle #4). Most likely is that he sent the money when I chased him, and if I hadn’t, he wouldn’t have sent it until I did. If he’d have paid by card, it would have been done and dusted before he left the car.

BACS would be better if you could trust everyone. If you want to trust up to 20-30 pupils at any one time, that’s your business. But you are deluding yourself if you believe you won’t have problems trusting pupils to use BACS, since the ball is always in their court at some point.

How long do PayPal Here payments take to clear?

For all practical purposes, they’re instant. They appear in your PayPal account within seconds. And when you transfer your PayPal balance to your bank account, that also occurs within seconds. My only minor gripe is that you have to transfer the money from PayPal to your bank manually.

How much does the card machine cost?

Right now, with PayPal, I’m not sure. PayPal is currently in a confused mess involving iZettle. When I used iZettle (before PayPal acquired it), it could take up to a week to receive money into your account. With PayPal Here it is in within seconds. I would like to think that the same is now true of anything to do with iZettle, but I cannot be sure.

Is there a monthly rental fee?

No. You buy the card reader outright and only pay a fee per transaction.

How much do they charge per transaction?

With PayPal it’s 2.75%. For each £29 lesson paid for by card, you ‘lose’ 80p. iZettle charged 1.75% per transaction when I used it. I am not sure how it works now with the confused mess PayPal has created, and been slow to clarify given that it purchased iZettle in 2018.

PayPal takes 23p for each £1 you take

NO. THEY. DON’T. YOU. IDIOT.

I saw some clown state this on social media, and it’s bollocks. On a £29 lesson, the fee is 80p.

Other card reader vendors have lower fees

I’m not saying you must use PayPal. Just be aware that other vendors’ fees are often on a sliding scale (iZettle’s was when I used them),  and you only get the lower rates on anything above the threshold they set. When I was with iZettle, virtually all my lessons were charged at the highest fee rate. I triggered iZettle’s lower rate fees a couple of times, but the lower rate only applies to takings above the threshold, and for driving instructors that is not going to happen regularly.

For example, if there is a threshold at takings of £5,000 per month, and you pay 2.75% up to that, and 2.5% above it, then if you take £5,500 in that month, you pay 2.75% on £5,000, and 2.5% on £500. To get any real benefit, you’d need to be taking £10,000 per month or more. Small multi-car driving schools might benefit, but a self-employed ADI wouldn’t.

What other alternatives are there?

SumUp is an alternative card reader provider, and has a fee of 1.69% per transaction. It takes 2-3 business days to get your money. A reader costs about £30.

Another alternative is Square, with a transaction fee of 1.75%. Apparently, money goes into in your account immediately. A reader costs less than £20.

I use PayPal because I like PayPal. However, if they don’t sort out the ridiculous confusion over whether they are now PayPal Here or iZettle, and clarify that iZettle’s pathetic system I had previous experience of is gone, then if all three of my PayPal Here readers were ever to fail, I would switch to someone else. I need to be able to take card payments, and I want the money immediately. That’s all there is.

Some vendors have no fees

And they keep your money longer before paying it to you to get their cut. There’s no free ride when it comes to clearing card payments. Someone somewhere has got to pay for it. And let’s face facts: it’s going to be you in the end.

The charges are a rip off

Fine. Keep taking cash and cheques, and pretend it doesn’t cost you anything to have to go to the bank to pay it in, or chase anything that bounces.

I can charge a ‘transaction fee’ to cover charges

No you can’t. It’s illegal. Just price yourself so you can cover the transaction fees you pay overall from your income, and stop trying to forecast it to the nearest fraction of a penny.

But I can save money if I don’t have to pay transaction fees

As I say. Fine. Keep taking cash. You probably also believe your car isn’t an overhead because you own it (it is an overhead, even if it is 20 years old), and that if you don’t have to pay a franchiser then you’re better off by the whole franchise fee (you’re not, because you still pay overheads, even if you don’t realise it). A card transaction fee is an overhead, that’s all.

I can’t see the point of taking card payments

Fine. Keep taking cash. This is how older or less clued up ADIs think, though.

What about cheques?

What about them? No one has attempted to pay me by cheque for at least 6 years now. Even before that, a cheque was often a way of paying for a lesson before they ‘got paid on Friday’ because they knew it would be at least a week before it was requested from their account. If someone can write cheques, they have a cheque guarantee card, and that has a chip & pin on it these days. If they use the card with my reader, I get paid instantly. If they use a cheque, I have to piss around getting it to the bank, and then hope their account will cover it when it gets requested.

I can take pupils to a cashpoint

Good for you. I’m sure they absolutely adore paying for a driving lesson which – in part – involves stopping to withdraw money every week. For me, my card machine is the cashpoint. In fact, on a couple of occasions, I have avoided having to go to a cashpoint because the pupil needed it for personal reasons nothing to do with the lesson, and handed them cash out of my wallet in return for a card transaction. It helped me avoid a bank trip, and the pupils were extremely impressed.

Is it of any benefit to take card payments?

It has saved me a lot, both in monetary terms, and in terms of my sanity trying to find a parking space near the bank or standing in a queue while stupid people take tens of minutes of the one cashiers’ time at my Halifax branch.

Another benefit is less tangible. Pupils are often impressed if you pull out an iPad and have a glitzy demonstration video to get some point across, for example. It’s exactly the same when you tell them you can take card payments.

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Kill Bill: Vol 1 - posterDuring the lockdown I was watching films and TV shows I’d downloaded and ripped from DVD. I prefer to watch videos on my TV rather than my computer most of the time, and I use Plex as my preferred media server.

Plex is great, but I was suffering from buffering problems when using it. A lot of others have, too, and from what I have deduced it isn’t specifically (or just) a problem with Plex, but partly with Wi-Fi. It is worse when you are watching 4K content, for example, because Wi-Fi just can’t handle the bandwidth in some cases – especially when you have several devices using it at once. Buffering was driving me insane to the extent that I tried various alternatives to Plex. But nothing comes even close to it for features and ease of use. The last straw was when I was watching Kill Bill: Vol 1 for the umpteenth time, it kept stopping during the fight scenes when a lot was happening and the required bandwidth went up.

How Plex works is this. You install Plex Server on your chosen computer, and tell it where your movies and other stuff is stored. Then you install Plex client on your smart TV, Firestick, or whatever, link it to your server, and you can watch your shows whenever you like. Most people will opt for Wi-Fi networking to eliminate the need for wires trailing everywhere in order to connect their devices.

I’m a bit of a Wi-Fi sceptic. I mean, it’s fine when it works, but it often doesn’t. The other thing is that my internet connection is 600Mbps, but there is no way Wi-Fi can match that. It doesn’t matter in most cases – when connecting devices to the network for updates and so on – but it does if you actually need the fastest connection for something. Or if you’re trying to stream high-bandwidth films.

Last year, I bought an Ethernet adapter for my Firestick (from where I run Plex client) and connected it directly to my router. Buffering disappeared, so that was one problem more or less resolved.

However, a related issue was to do with storage. My PC, which I built myself just over a year ago, has two 1TB SSDs and one 2TB SSD. You’d think that 4TB would be enough space (I also have a spare 2TB SSD which I was planning to install), but I then realised I’d got around 3TB of movies and TV shows, with the entire box set of Frasier still to rip at some point, which will add probably another 2TB. SSD is an expensive way of increasing storage, and you still have the potential for a disk failure eventually, which means you lose everything on it (I got stung with that previously when we had a power cut that blew my last self-built machine). I needed something bigger and safer

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Now, I said I was a bit of a Wi-Fi sceptic, but I am a full-on ‘cloud’ sceptic. The idea of trusting all of your files to the cloud just doesn’t make sense to me. For one thing, it is expensive if you want a lot of storage (Amazon used to offer an unlimited cloud service, but it was being abused and they stopped it). And unless you pay for it (I assume), the cloud is sloooooow. I have a 1TB OneDrive account through my Office365 subscription and if I want to download a movie file from it I can assure you it isn’t downloaded at anywhere near to my 600Mbps internet connection speed. Uploading such files is worse because of the massive difference in upload speeds even with your ISP.  Then you need to factor in how fast your cloud is going to let to have the file – usually at about a tenth of that speed if you’re lucky – and it’s a nightmare. The download also seems to be proportional to how urgently you need it – if you’re desperate, you can virtually guarantee an outage somewhere or download error.

I’d been considering a NAS (Network Attached Storage) solution for a while. This is just a storage system you maintain yourself. I wanted to be able to store and access large files immediately – not tomorrow, after several failed tries. I also wanted to be able to work on them where they were stored – just like on your PC – and not with the extra steps of having to download them first, altering them, then having to upload them again. A NAS is exactly what it says – a disk storage system that is on your network, and not someone else’s.Synology DS1821+ NAS

Be aware that a NAS is not a cheap solution to begin with. Once you have it, it is virtually free, but a NAS enclosure starts at around £150, and disks to populate it at around £70 each. I opted for the Synology DS1821+ DiskStation 8-bay, which costs just under £1,000.

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You can set up a NAS using single disk drives, where each drive acts just like one in your computer. However, if the drive fails at any point, all your data are lost. I’ve been bitten with that before, as I mentioned. I wanted better security, so I wanted a RAID system – where you use multiple disks to either ‘stripe’ the data or ‘mirror’ it. This is where you have to trade off the level of security/safety against reduced capacity. For example, if you simply ‘mirror’ across two disks (RAID 1), then you might have two 1TB disks which have the exact same data on them, which is secure if one fails, but you only have 1TB capacity, even though you have two 1TB disks. To cut the story short, I wanted RAID 5, which needs at least three disks to ‘stripe’ the data, but which gives you the capacity of two of them whilst still retaining all data if any one of the three fails. Weighing up the prices of the available disk drives against my likely storage requirements I bought three 12TB HDDs at a cost of £270 each. This would give me 24TB of storage, with the additional data security I wanted.

A NAS is essentially a PC – a computer. It runs its own operating system, which on the Synology is called DiskStation Manager. It is just a black box you put on your desk, and you access it through a web interface in your browser once you’ve connected it to your network via the router. Installing the hard drives is easy, and once you’ve plugged in the necessary cables and turned it on, finding it it and adding it to your network is also easy. Various guides take you through setting up your chosen RAID configuration, and that is very simple too. After that, all you have to do is map your drive from Windows on your PC and you can use it.

An additional detail that cropped up was when I accidentally pulled out the plug for the NAS one time, and the system reported an unexpected shutdown after rebooting. It also warned that this could lead to data loss and disk corruption – a major alarm bell for me – so I got a UPS (Uninterruptible Power Supply) to prevent that happening again. A UPS is a battery backup system, and I already have one for my PC after that damned power cut blew all my disks. I chose an APC unit which has a data link that the NAS can interface with and perform a controlled shutdown if the power fails and the battery runs out. It cost £110.

I now have a neat system where I have 24TB of storage that I can access at network speeds. I can access it as a normal ‘disk drive’ from my PC, or via the internet on my laptop or smartphone if I wish, wherever I am. It is connected by cable to my Firestick, so there’s absolutely no buffering. My data is more secure than if I was operating on single drives (and I’ve been caught out with that previously, as I mentioned). I can expand if I need to. It is my own ‘cloud’.

I have installed Plex server on the NAS, and linked Plex client on the Firestick to it, and there is no buffering whatsoever. All my content is now on the NAS. And if I want to work on a file, it is just on another drive which I can access whenever I want. No more download, fiddle around, then upload.

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The Chillmax AirI wrote this in the very hot summer of 2019, but each year around spring time adverts start appearing involving these ‘revolutionary no-install air conditioners’.

Be aware that these devices do not work to anything like the levels claimed. The original article follows.

Early in July 2019, I saw the Chillmax Air advertised on TV in one of those shouty ads. Then, the same evening, I was shopping in Asda and saw it on display. I am an idiot for things like this, and bought it on impulse so I could test whether it worked or not.

As a chemist, I know that in order to cool a large space effectively you’re going to need something with a big fan and a special refrigerant. In practical terms, that means a fairly bulky device with a motor-driven compressor, a closed radiator for the refrigerant to pass through, a fan to suck air in and blow it across the radiator, and a wide exhaust pipe through the wall or window to get rid of the ‘removed heat’. In some cases, you also need to collect or drain the condensed water that comes out of the air as it cools. A typical proper air conditioner for a small or medium-sized room will be about the size of bedside cabinet. The Chillmax Air is not much bigger than six CD cases glued into a cube.

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If you’ve used a normal desk fan you will know that you only feel cooler if you’re sweating a bit. That’s because the fan evaporates your sweat as it pushes air over it, and that evaporation is accompanied by a small cooling effect – it’s called ‘evaporative cooling’. If you’re not sweating, you don’t feel the effect. Conversely, if the surrounding air is very humid, then no matter how powerful your fan is, you will feel little or no cooling because sweat can only evaporate if the air has capacity to hold additional moisture (I’ll explain that a bit more later, because it’s what determines whether the Chillmax is any good).

As an aside, many liquids exhibit the evaporative cooling effect. In the case of diethyl ether (the stuff they used to use as an anaesthetic), if you force it to evaporate very quickly you can even freeze water (if you do it properly). However, ether is both highly flammable and toxic, so apart from demonstrating it in the school lab (where I remember it from, partly due to the massive headache the fumes gave me), it doesn’t have much practical application these days. Early refrigerators used it, which was spectacularly dangerous.

The Chillmax Air uses the evaporative cooling effect of water, and this is much less than with ether – similar to sweat, in fact. The unit consists of a reservoir at the top, which you fill with normal tap water, and this drips down on to a radiator unit which has ten sideways-stacked fibre panels in it through which a fan blows air. The water evaporates from the fibre panels, and the evaporatively cooled air comes out through the front grille. According to the marketing spiel on the TV ads, you’d be forgiven for thinking you’re going to get frostbite if you sit too close. I knew this wasn’t going to happen, but I wanted to know just how effective the Chillmax was.

When I first set it up and turned it on, the first thing I noticed was that the fan is quite powerful, so you get a good flow of air directed at you – but note that that it’s only a 5″ computer fan, so it can’t beat a proper desk fan for air flow. The air did seem a little cooler compared with what my desk fan was blowing at me, but it also felt ‘softer’ – that’s very important, and I’ll explain later. But the big question was how much cooler was the exhaust air?

I fired up my trusty data logger and left it in front of my desk fan for 30 minutes for the control data. Then I moved it and suspended it in front of the Chillmax for the same period of time. This is what it recorded (the red line is where I moved it).

Chillmax - temperature log in hot and sticky conditionsThe ambient temperature where I ran the test was about 29ºC. The Chillmax brought this down by about 4ºC.

So, the Chillmax definitely cools the air that passes through it. Let’s work on the assumption that it would be able to get the same 4ºC drop no matter what the ambient temperature was. If your room is 38ºC, pulling it down to 34ºC still means it’s bloody hot. And also note that since the Chillmax is physically so small, the cooling is very localised – it won’t cool a room down, and you have to have it less than a metre from your face to feel anything.

Now, some people might be thinking that a 4ºC is better than nothing at all. And they’d be right if it was just a matter of temperature. But there’s more to it than that. I mentioned that the exhaust from the Chillmax felt ‘softer’. I knew what it was, but my data logger shows it in numbers.

These are is the data for relative humidity recorded at the same time as the temperature measurement, above (the red line is where I moved the logger). The humidity went up dramatically – a jump of about 30%RH.

Chillmax - RH log in hot and sticky conditionsAs I’ve already explained, the Chillmax works by evaporating water on fibrous panels by forcing air across them. That water has got to go somewhere, and in this case it comes out as vapour in the cooled air. In the right light, you can actually see it – it’s essentially fog. And just like when it’s foggy outside, and everywhere gets damp, this vapour can condense on surfaces. My data logger collected some and began to drip during the test, and I have since discovered that it also condenses on the front grille and can drip periodically, so you’d need to be careful what you had underneath it if you placed it on a shelf. The fan is quite powerful enough to project the drips forward slightly when they drop.

The ambient humidity in the room where I did the test was about 44%RH. The Chillmax sent that up to over 70%RH.

It’s this elevation of the humidity of the cooled air which really brings into question whether the Chillmax is worth the investment. You’re probably aware that you can have a hot summer day in the high 20s where it is pleasant and comfortable, but a cooler and overcast day might be horribly sticky – or muggy. That’s because of the humidity, or water vapour in the air.

The amount of water vapour that air can hold varies with the temperature. Once you reach the maximum, any extra vapour condenses out as a liquid – misted up windows, dampness, even drips and pools of moisture on window sills or under lamp posts. Cold air can only hold a small amount of moisture before condensation occurs, but hot air can carry much more (think ‘sauna’). Although ‘humidity’ technically refers to the amount of water in the air, the figure most people are referring to when they say it is relative humidity. This is the amount of moisture in the air expressed as a percentage of the maximum amount it could hold at that temperature, hence the units %RH. It’s a very complicated subject, but the important factor for us here is that when it is warm or hot, higher relative humidity is uncomfortable. Indeed, you may have seen weather forecasts where they give the actual temperature and the ‘feels like’ equivalent – that’s a reference to the ‘Heat Index’, which takes into account the effect of the %RH. Here’s a graphical chart for that.

Heat Index - graphical representationAs an example, if the air temperature is 30ºC and 50%RH, it will feel like 31ºC, but if the humidity goes up to 80%RH, then it will feel like 38ºC – even though the thermometer still tells you it’s 30ºC.

Another example. If the air temperature is 35ºC, at 50%RH it will feel like 41ºC, but send the humidity up to 80%RH and it’ll feel like 57ºC – even though the thermometer still reads 35ºC.

The calculation for this is complex (you should see how long my Excel formula for it is). It is non-linear, and the increase in ‘feels like’ is greater at higher temperatures. It also contains an element of opinion/perception, which is why there’s no point using numbers above about 60ºC. But the ‘Heat Index’ is what forecasters use. Incidentally, the official health designations for the colours are: yellow – caution; amber – extreme caution; orange – danger; and red – extreme danger. Vulnerable people need to take these into consideration before going out in hot weather.

However, this is where the problems come in for the Chillmax and similar devices. If it’s 35ºC and 40%RH, it’ll feel like 37ºC. Cool the air to 31ºC but send the humidity up to 80%RH, and it’ll feel like 41ºC. So it’s actually hotter in terms of comfort. Do the same comparison when the surrounding temperature is 38ºC, and the ‘feels like’ goes from 43ºC to over 50ºC!

At lower temperatures the Chillmax will produce a slight net cooling effect. But if the air temperature is above about 30ºC (and 50%RH) – which isn’t excessively hot or humid to start with – it’ll actually make you feel warmer. And if it is already humid outside, you’ll feel hotter still.

Proper air conditioners remove water from the air they cool. This removal of moisture is why the air from proper air conditioners feels crisp, as opposed to the ‘softness’ of moist air. The Chillmax does the opposite of normal A/Cs, and adds moisture.

Aesthetically speaking, the Chillmax is a cube – more or less – about 15cm along each side. There are two buttons on the top rear, one which changes the fan speed to one of three settings (or off), with a blue LED for each, and another button that turns the night light on or off. There’s a flap on the top front through which you add the water. The radiator system is a plastic-framed insert which you access by pulling the front grille out. It slots in and out easily. You can’t officially replace the fibre inserts in the radiator, but you can buy the whole radiator assembly from JML for £15. My only major gripe is the power cable. The jack plug that goes into the Chillmax is quite stubby and doesn’t go into the socket very far, so it is easy to dislodge it. However, the cable itself is quite long, and the  mains plug is a moulded UK type.

JML claims the Chillmax can run for up to 10 hours per fill, but this is likely on the lowest of the three fan speeds, since on top speed it runs out in less than three hours.  JML sells the humidification as a positive without relating it to the comfort relationship between temperature and %RH, but note what I said above. If you want to cool down in humid weather, it isn’t just the temperature that needs to come down.

Does it really work?

It does cool the air by a few degrees, so in that sense it works. However, it also sends the humidity up, and in most cases that actually makes you feel hotter and more uncomfortable. In that sense, it doesn’t work.

Will it cool more if I use ice water?

No. Evaporative coolers are not influenced significantly by the temperature of the water used in them. The temperature of the air that comes out depends on the temperature (and humidity) of the air going in, and the science of evaporation. Only this evaporation results in the cooling effect observed.

Will it cool more if I put the filter in the freezer?

It might – while you’re blowing air over ice. But once they defrost, which will happen in a few minutes in the temperatures you’ll likely be experiencing, then no. You’ll also have more condensate to deal with from the melted ice pouring out of the front grille.

You may see reviews on Amazon claiming that freezing the filters (or using ice cubes in the water tank) does give cooler air. Trust me – apart from what I just said about blowing air over ice, it doesn’t. Science is involved, and evaporative cooling doesn’t work like that.

Can I use it to cool my PC?

Someone found this article on the search term “jml chillmax air for pc cooling”. No. Blowing damp air into your PC would be dangerous, potentially expensive, and would only gain you 4ºC at best.

Can you get larger versions?

You can certainly get larger evaporative coolers, though not the Chillmax specifically. The working principle is that the larger the surface area of water, and the greater the airflow over that water, then the greater will be the possible drop in temperature at the front end. However, cooling effectiveness is influenced greatly by the RH of the air going in.

If the air is very dry, then a large evaporative cooler might be able to drop inlet air at 30ºC down by as much as 10ºC. However, if the inlet air is very humid, the temperature drop could be as little as 1ºC. In the UK, the realistic temperature drop you could expect on a non-humid day for a large cooler would be around 5-6ºC, but on a sticky day you’d only get about a 3ºC drop.

Suppliers of these devices say that they need good ventilation or extraction, and I would imagine that’s so the humid air can escape. If you’re evaporating more water to get better cooling on larger devices, you’re also producing a lot more water vapour. Be careful if you read any of the reviews – people may have noticed cooling in already cooler conditions, but trust me – if it’s very warm and humid, you will not notice any effect.

People say it works

Be careful when you read those one-line reviews. If you test it when it’s only 20ºC outside – as many of these people have – then yes, it blows noticeably cooler air at you. But science is involved, and at temperatures above about 28-30ºC you’ll actually feel hotter. The fact that it increases humidity is the key factor. Remember that the reason you even found this article was probably because it’s over 30ºC outside – the more above that it is, then the more hits I get.

So, does the Chillmax work?

It cools the inlet air by several degrees. But it sends the humidity of that air up considerably, and this cancels out the benefits of the cooling effect when it is very hot. The ‘Heat Index’ is the key detail, as explained above.

Only the air being directed at you is cooler. Once that slightly cooler air has passed through warmer air, it’ll be close to ambient again. The device cannot cool down a room. It’s far too small for that.

Humidity can carry much further, though. So in a small room, you could easily increase the ‘ambient’ RH without any cooling at all, and that will make it feel even hotter. If it is already hot, the amount of water vapour the air can hold before reaching 100% RH will be substantial. The increased humidity of the outlet air does produce localised condensation, so you have to be careful to keep it away from electrical sockets where it might drip on them. The unit also contains a significant volume of water when full, so you don’t want to knock it over.

Should I buy one?

My advice is to buy a proper air conditioner (A/C). If anything costs under £100 it is not a proper A/C. However, it is possible some people might find the minor cooling effect and increased humidity of the Chillmax (and similar devices) beneficial, so the choice is yours. But for real cooling and dehumidification when it is hot, it has to be a proper A/C.

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MeowTalk from AkvelonMankind has this never-ending belief that animals have their own languages. There’s maybe a possibility with apes and monkeys, but when you start moving to different branches of the evolutionary tree, I think you’re stretching it a bit.

The latest story is to do with a cat translator app – called MeowTalk – which aims to translate your cat’s meows into meanings.

The article on the BBC website says:

Research suggests that, unlike their human servants, cats do not share a language.

Each cat’s miaow is unique and tailored to its owner, with some more vocal than others.

Apparently, this isn’t seen as any sort of problem to the engineers who developed the app. But let’s be honest. It is. A big problem.

We had a cat once where visual clues were far more important in knowing what she felt. If she hissed and drew up to 20mls of blood from you, she was happy – but now fed up with being stroked (she could become fed up anywhere from 5 seconds to 20 minutes after commencement of stroking, but there was no obvious way of knowing which one it was going to be on any given occasion). If she hissed and drew 40-50mls of blood, it meant that she didn’t want to take the tablet you were trying to give her, but which she’d swallowed voluntarily when the vet had demonstrated how to do it only yesterday. If she hissed and drew more than 50mls of blood, she didn’t want to be flea-treated. Sometimes, as you walked past her on a chair, and if she was in a playful mood, she’d lunge at your leg and draw varying amounts of blood depending on whether she hit a vein or an artery without making any sound at all.

I don’t think they have an app for that, though if they did let me just say that ‘PsychoMeow’ is copyrighted.

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I just had to get me one of these!

I’ve been fascinated by drones for years, and always had plans to get one. They’re a tad expensive, I admit, but I saw that DJI were just about to release the Mini 2, and I thought it would be an ideal opportunity to get in on the ground floor. So I ordered the Fly More Combo pack through Amazon, and it came next day.

The Mini 2 weighs just under 250g. When you fold out the four propeller arms and remove the gimbal (camera) cover, you’re ready to take off. Well, you are once you’ve set everything else up – which isn’t difficult at all.

The kit comes with a remote control unit, and you need a smartphone to use it. You have to download the DJI Fly app and run through the setup process, which only takes a few minutes, but then you’re good to go.

I wanted to be within the Law, so I went to the Civil Aviation Authority (CAA) website and passed the necessary test to become an approved drone pilot (it’s free). That gave me my pilot/flyer number, which I’ve stuck on the side of my drone. It’s valid for three years. Technically, I didn’t need to do this for the Mini 2 as it weighs less than 250g – but only just, so I thought I may as well in case I upgrade at any point (in any case, the sticker I put on it with my flyer ID has probably taken it to 250-251g).  It only took about 15 minutes of revision to pick up some of the numbers about how close to people and buildings you should be, and that was that.

The Mini 2 records at up to 4K video, so it is broadcast quality. You can alter the video quality down to HD, and change the frame rate, but 4K can record at up to 30fps. In HD, it goes up to 60fps. It doesn’t record automatically the moment you turn it on, and you select the function through the app as you’re controlling the drone. This is a sample of what I recorded recently, showing the three levels of zoom available at 4K.

And this is an example of a slow pan at around 80m altitude.

Incidentally, I was terrified of how well I’d be able to control it, so I made sure I was in a big field with nothing I might hit anywhere near me.

The Fly Combo kit comes with three batteries, and each will give about 30 minutes of flying time. You also get a spare set of propellers (4 x 2) and screwdriver to replace them with. A spare set of propellers (if you needed one) currently costs £11 from DJI, so no big problem. The thing is, they are very fragile, and if you were to let them hit anything then they could easily shatter. I think they’re made from carbon fibre, but they are very light.

Control is smooth and easy. You’re not going to fly into things unless you’re a total klutz. You can buy propeller protectors if you’re worried, anyway. When hovering, it is rock-steady up to Beaufort Scale 5 (fresh breeze). You can also get a 1-2 year accidental damage warranty, which is offered when you sign up to the app during registration – and I recommend doing it, just in case. It isn’t expensive.

The Mini 2 has a range of 4km (4,000m), but you should never let a drone out of your sight, and in the UK you’re limited to 120m (400 feet) altitude and how close you can get to people.

If you’re buying someone a Christmas present – and if you’re going to splurge, as opposed to buying them socks or deodorant – this is the way to go! It is brilliant fun, with the bonus of superb quality video.

As I say, these samples were taken in a field not too close to buildings when I was out testing it just after I got it. It’s a great experience flying it around, seeing it ascend and descend, and race around a large open space. But it is also good for stable stuff – checking the pointing on chimney stacks, for example. Once we’re out of COVID, I’ve got lots of plans for where I want to fly it.

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I should point out that DJI drones are probably the best you can get (certainly one of the best), but there is a plethora of cheaper drones that are ideal for kids or those on a smaller budget. This is just a sample.

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Ring 3 Plus and Chime ProDuring the lockdown, I took the plunge and bought a Ring 3 Plus video doorbell. After unboxing, setting it up was easy, and it connected to my home network with no problems.

After I’d hardwired it in and located it outside the front door, it was working fine. The only thing niggling me was the fact that since the distance between my router and the doorbell was about as much as it could be, and went through every wall and floor possible, the doorbell signal showed up as ‘poor’ on the Ring app. I don’t like things like that and had plans to resolve it later.

Then, once I knew the doorbell worked as it should, I bought a Chime Pro (2nd Generation). This contains a network extender, and once set up you have the option to switch your doorbell to the ‘Chime network’, for which the Chime Pro is effectively the hub.

The Chime Pro has only one button – a reset – and is a small box which plugs directly into a mains socket. In theory, you plug it in, connect it via the app, and you’re done. But it is the most God-awfully difficult thing to get to connect. I managed it eventually (actually, twice eventually, as you will see), though I have no idea what I did to get it to do so.

Now, when the doorbell is connected to the Chime Pro network, it has a ‘good’ signal. But the Chime Pro is also downstairs, and it still has to connect to the home network upstairs. And although it has fewer walls and floors to get through, the signal to my main router was still showing as somewhere between ‘OK’ and ‘poor’. My plans to resolve the issue now came into play.

I next purchased a TP-Link AC2600 range extender. That was a bit of a pfaff to get going, but following a YouTube video from TP-Link – which fully contradicted the idiotic ‘expert’ reviews on Amazon – it worked first time just by pushing the WPS button on the extender and my router. In hindsight, I suppose it was actually very easy to set up – but only if you watched the video, since the instructions that come with it are useless. But now the fun started – and bear in mind that the doorbell and Chime Pro were working flawlessly other than for the signal strength up until this point.

The first obstacle came when I realised that the TP-Link extender puts out its own SSID, and so is effectively a completely separate network. Two networks, actually, since it has a separate SSID for 2.4GHz and 5GHz. I spoke with Ring technical support to ask about changing to a new network. To be fair to them, they try to be extremely helpful, but – like many tech support lines (and I used to work in one, remember) – the people staffing them don’t necessarily fully understand what you are asking them, and don’t necessarily fully understand what they are trying to tell you. Consequently, I opted to simply delete everything I had previously set up, and start all over again.

After removing all registered devices from the app, I started the set up process for the doorbell again. I hit a brick wall straight away, since the app asks you either to scan a QR code or enter a 5-digit number printed below the QR code for your doorbell. And where is this code? It’s on the back plate of the doorbell case – which in my situation was screwed against the brick wall of my porch!

Lesson #1: When you set up any Ring device (they all have these identity codes), write the 5-digit number down somewhere and keep it safe before you try to install anything.

Anyway, whereas the first time I set it up simply chose my home network, this time I had two others to decide between – the 2.4GHz and 5GHz signals coming from the extender. I had noted that when I installed the doorbell the first time, it had automatically connected to my home network’s 2.4GHz channel, so that was the one I chose here – but this time, the one coming from the extender. It ran through the app process and connected first time.

This was where the fun started again. I now came to install the Chime Pro, and – just like before – it didn’t want to. I’ll cut a long story short, and point out that when I chose the 5GHz channel on the extender instead of the 2.4GHz one I’d been playing with, it connected. I’m not sure if it connected first time, but it connected.

At this stage, everything seemed to be working. Signal strength was now ‘good’ for both devices. However, later on when I switched to ‘live view’ on my PC – trust me, if you get one of these things you’ll keep playing with it to start with – I got a blank screen. I tried a few more times and live view appeared. But over the next few hours it was intermittent between a blank screen, a normal image, and a variably grainy one. That persisted into today. Obviously, something was still not right.

I should point out that the doorbell and Chime Pro were still working, and I was getting notifications when someone came to the door or if they pressed the bell (why do people knock when you’ve got a bloody bell?) Video was being recorded and saved. It was just live view that was playing up.

During the day, I was looking for possible issues reported by others on the internet. The Ring doorbell now exists over three generations, and in at least two of those generations there are three different doorbells – one of which is substantially different from the other two in each case. It means that anything you find by Googling is likely to apply to any one of up to nine different models, and is heavily biased to the older generations, and the model that is substantially different in each generation. Even Ring’s own support pages are a convoluted mess covering multiple devices and multiple generations, with very little specific information covering equivalent issues for the latest generation. It’s also not helped by the fact that Ring assumes – and most people who install them apparently fall into this bracket – you will want want to wire them up in parallel with existing doorbell systems and chimes. I wanted a clean and independent install, and it would appear that I am the only person in the entire known universe who did.

At this stage, with the dodgy live view issue, the doorbell was connected to 2.4GHz, and the Chime Pro to 5GHz. However, when I switched the doorbell over to the Chime Network – thus eliminating 2.4GHz on the extender altogether – the whole system is working flawlessly again. And with a strong signal all round. Basically, I have the doorbell connected to the Chime Pro, the Chime Pro connected to 5GHz on the extender, and the extender connected to my home network. And since I will be needing another Chime, I am anticipating that connection directly to the Chime network will be easier than having to fiddle with the other stuff when I do.

From what I can gather, the Chime Pro (and possibly even the doorbell, though I didn’t experience issues with that) is very sensitive to what network options it sees when you are setting it up. One piece of advice I saw this afternoon recommended running set up on the app in Aeroplane Mode so that the phone signal is off. In my case, it is possible the 2.4GHz signal was suffering interference from the other stuff I have in the house, or even that the extender uses a different protocol that was causing issues. I don’t know. All I do know is that I’d forgotten how much I dislike tinkering with networks, and why I dislike tinkering with them!

Anyway, if anyone approaches my front door now the Chime Pro gives an audible warning downstairs, I get one on my PC upstairs, and an alert on my phone. You can select which sounds you get, and which devices give alerts (or not). This is useful, as I discovered this morning at 1.43am, when our milkman made his delivery and the system gave its chime for that! Or at 4.45am, when the paperman delivered the newspapers (and stared right into the camera)! The same is true when someone pushes the doorbell. In both cases, the doorbell records video in HD and saves it to the Ring cloud. You can set motion zones so it doesn’t pick up people walking on the pavement, and you can set it to distinguish between humans and vehicles (not tested that thoroughly yet). You can also set up schedules, so that it won’t sound at times when you tell it not to.

The doorbell also switches automatically to infrared recording when light levels fall at dusk. In this case, recordings are in black and white.

By itself, the doorbell is battery-powered. The battery lasts for a long, long time per charge, but it also takes a long, long time to recharge it. About ten hours, in fact. So you’d need a second battery unless you were prepared to be offline while you were recharging (and there’s a small security screw that’s just itching to get lost that you have to take out in order to remove the battery, unless you want someone to steal it). However, you can hardwire the bell so that the battery is trickle-charged permanently – the bell still runs off the battery, but the hardwire keeps the battery charged up.

All in all, if you can live with the fact you have to drill holes in your wall or door frame, run a wire to a suitable power outlet if you want permanent power, and fiddle around with possible network issues, the Ring Doorbell is an excellent security device.

Oh. And I should mention, you can have people fit them for you.

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Virus imageMy feelings on this government, the Tories in general, and Brexit are well known. But I don’t go so far as to blame them for everything. Only the things they do wrong.

The new Test & Trace app is now available. I downloaded it with no trouble, and it runs with no problems that I can see on my  HTC U11 (come on, HTC, I want a new flagship) from 2017. All you have to do is enter the first part of your postcode and allow a couple of permissions and it is set up. However, the way the app works means that it has to be installed on relatively new phones which have the necessary Bluetooth features on them. Note that I said the necessary Bluetooth features – not Bluetooth per se. The iPhone 6, for example, was released in 2015, and Apple stopped supporting it and earlier models this year. So in other words it is obsolete, and no one in their right mind should automatically expect any new app to run on that phone.

The Test & Trace app doesn’t.

Matt Hancock has gone on record as saying an ‘upgrade’ maybe needed to access the app. Rightly or wrongly he’s going to get slated for this. It’s his ‘let them eat cake’ moment. But how is it his problem? It’s like complaining that you can’t play a C60 cassette in a CD player, or a VHS cassette in a DVD machine (though it’s worth pointing out people did complain when those two things were current issues).

I’m not saying the app is perfect, or that it works properly – I don’t know, and time will tell – but the vultures are out in force over it simply because they can’t download it on to two tin cans joined by a piece of string. It only works on iOS 13.5 and later – and that counts for 70% of the iPhone-owning public. It will only run on Android Marshmallow or later – again, from 2015 – and that covers over 80% of Android users. It doesn’t run for the tiny minority using Windows, Blackberry, or anything else. It doesn’t run on phones which aren’t ‘smart’ (think ‘original Nokia’). And you can’t use it if you don’t have a phone at all – and believe me, there will undoubtedly be some people who are in that bracket who are complaining.

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NextBase dashcamI first published this in 2019, but recently noticed people having dashcam issues which are likely connected with this topic. The original article follows.

A bit of advice to anyone using a dashcam. I see a lot of people complaining that theirs is playing up, and other advice to regularly reformat the card – which seems to get a lot of people recording again, at least for a while. I strongly believe that part of the problem is with the card, and not the dashcam. Specifically, people are using the wrong cards – and that’s true, even if they’re the ones their camera’s manufacturer is recommending.

I have always used SanDisk Extreme cards in my dashcams, and I have not had any problems. Extreme cards are not the cheapest, either. They’re pretty high spec. However, as a result of something I’d read online, I wrote to SanDisk and asked them if Extreme cards were OK to use in such dashcams. Here is what they replied:

Thank you for contacting SanDisk® Global Customer Care. Please allow me to inform you that for Dashcams & security surveillance cameras, we recommend to use SanDisk® High Endurance Memory Cards since these cards are specially developed for high endurance applications and continuous read & write cycles. These cards are built for and tested in harsh conditions and are temperature-proof, shock-proof and waterproof.

Also, please be informed that using Extreme or Ultra line memory cards on these devices void their warranty.

The text in that last sentence has been emboldened by me. At this point, it is worth noting that “high endurance” cards are special cards. They’re not easy to get hold of except through specialist suppliers, and your local PC World or Currys branch is unlikely to have them in stock. They cost more than normal cards.

But the upshot is that using Extreme (i.e. high-end “normal”) cards puts them under stress that they’re not designed for. It voids their warranty, but – more importantly if you read between the lines – there is a good chance they will malfunction or play up. I don’t know much about cards from other manufacturers, but I would lay odds that most people with dashcams are using the cheapest card they can get their hands on, and that means they’re not “high endurance” types – and probably not even branded. Most of the time I see people asking what dashcam to choose they always want a cheap one, and the one they end up buying often costs them less than I pay for a SanDisk Extreme card – so there’s no way they’re going to buy a card even close to that.

My current dashcam is the NextBase 612GW. It records in 4k, and on cards up to 128GB (so I get about six hours of footage in a write cycle).  I have never had any problems with Extreme cards, but after the SanDisk advice I invested in a couple of Samsung 128GB high-endurance cards. I wanted SanDisk, but at the time they didn’t do them above 64GB. However, they do now (including a 256GB one) – and they’re reasonably priced, too.

They also now have a range of Max Endurance cards of the same capacities, which do the same job, but are warrantied for 120,000 hours of continuous recording (over 13 years)!

When I originally wrote this, NextBase would not enter into discussion over the matter when I told them what SanDisk had said. They recommended using Extreme cards, and were (and still are) adamant that they work. However, I have noticed in their latest camera documentation that they strongly advise use of their own branded Class 3 cards, and point out that these are more expensive because of the extra work they are required to do. They don’t provide detailed specs, though, so I can’t say if they’ve used higher-rated cards than Extreme. At least you’d be covered under NextBase’s warranty if the card failed, so you’d have that extra level of security – which is missing if you use a SanDisk Extreme card.

I don’t disagree that Extreme cards have worked well for me, and they probably do for most other users, especially when they’re new. But the niggling problems people keep reporting are nearly always card-related. NextBase isn’t doing itself any favours by recommending Extreme cards (or if it is rebranding them), because if the camera doesn’t record people immediately blame… the camera. And even if it is shown that the card is faulty – even if they have been using one that cost them nothing and came in their cornflakes – they still blame the camera.

The bottom line is that SanDisk have told me very specifically that Extreme cards are not suitable for dashcams, and that using them for such voids their warranty. You cannot get much clearer than that. And it stands to reason that if you’re doing something that voids their warranty, the chances are it isn’t actually very good for them – and they break.

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TV Licensing ScamJust a heads up on another silly attempt at scamming people over their TV licence.

I get one of these at least once a year and can spot them a mile off. This one (in May) came from postmaster@kuriya.jp, which is an automatic giveaway in the first place. The second clue is in that I know our licence is up to date. The third clue is that ‘TVLicensing’ and ‘TVLicence’ have no space, whereas the proper TV Licensing title does. Edit: I had another one in June, which I just binned, and another just now from ‘support@tvlicensing.co.uk.a’ (see the extra ‘a’ at the end?)

TVL will always use your full name in their own emails (this one had my email address), and they will always come from donotreply@tvlicensing.co.uk or donotreply@spp.tvlicensing.co.uk.

And never click on links from emails if you are unsure of them.

If I’m wrong, then I expect a visit from the Yakuza in the near future. I’m not especially worried.

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