New Kcom Tariffs can save you money

I’ve just changed to a new contract for my home networking. The speed goes up, the amount of data stays the same and the price drops by eleven pounds a month.

What’s not to love?

If you’re in Hull you really should take a look here and see if there is something cheaper that you can change to. Hull is already one of the best connected cities in the world, it’s nice to see it getting cheaper as well.

Stealth Selling

Old joke: “They say that money talks. The only thing it says to me is ‘Goodbye’”.

However, these days it doesn’t even do that. When Netflix (or a host of other subscription services) take their fees from my account they do so invisibly. The only way that I know that it has happened is by carefully checking my statements to find out why the balance value is dropping.

Today I found that a service I thought I’d cancelled ages ago has been racking up these “stealth charges”. Of course it’s my fault for misunderstanding what I was paying for, but if I’d had regular emails each time that the fee was paid I’d have spotted the rogue transactions much earlier.

It’s as if they don’t want to tell you when they take money in case you notice and cancel something…..

I reckon that a service provider should be forced to send you an email or a text each time they take your cash off you. These companies seem happy enough to send me emails advertising new things I can buy from them, it would be rather nice if they also told me when I had bought something.

Happy New Year from Hornsea

We’ve got a tradition of going out to the seaside on New Year’s day. We didn’t do it last year, but this year the weather was so nice that we couldn’t resist it. So we headed down to Hornsea to see the sea. We managed to make the morning perfect by finding the Hornsea Floral Hall, where they were serving bacon butties.

The thing about a bacon sandwich is that once you’ve heard someone mention one, you really want one for yourself. The chap in the queue in front of us ordered a buttie and so we of course had to follow suit. It was really really nice.

What a great way to start 2019.

New Year Resolution Time

As the year ends it is time to think about new year resolutions. One of mine is that I’m not going to make the very old joke about getting a different computer monitor.

The other is to try to be a bit more assertive in the new year, or at least to stop apologising when cashiers in shops ask me “Do you have a loyalty card?” when I try to buy something. Up until now I’ve always said “Sorry, I’m afraid not”. From now on I’m just going to say "no”. That’ll make a difference to my life, no doubt.

I’d like to wish all (or is that both) my readers the very best of times in 2019 and beyond.

May your code always compile and your solder always stick.

Invisible hearing aids and other frauds

I was very upset to discover today that a shop in Cottingham (where I live - the village not the shop) has taken away their “Invisible hearing aids - 475 pounds a pair” sign. I really wanted to get a photograph of that sign.

The way I see it, advertising things like this is fraught with fraud potential.

“I say, there’s only one hearing aid in this box”
"That’s because the other one is switched on”
.. and so on.

They’ve now have a sign that that says “Free Eye Tests”. I can see fraud potential here too:

“We’ve done your test, that will be fifty pounds please”
”Hang on, the sign says that you do eye tests for free”
”Ah yes we do, but the charge is for testing the other eye. That costs fifty pounds….”

Sometimes I consider myself a great loss to the world of commerce.

Bank Heist Fun

As part of our Christmas present, number one daughter organised a trip to an escape room in Hull. This was a room with a difference. It turns out that there is no problem escaping, you can leave the bank at any time. But, you’ll want to take away a few souvenirs in the form of wads of cash, gems etc etc.

The puzzle was a very good mock up of a bank branch (remember them), even down to the pens chained to the desk. And there was a strong room, and things containing money and clues in equal measure. I’m not going to tell you much about the puzzles, except that they are fun and the whole thing works very well to build tension during the hour you spend trying to get your hands on as much loot as possible.

We did OK, and each of us got a cheque for our share of the take. You can see mine above. It’s lovely to have these kinds of things in Hull. If you fancy a fun and challenging trip out I can strongly recommend it.

Neopixel leds and power supply fun

When you try to make hardware it sometimes turns out that every bit is the difficult bit. Like today for example. Yesterday my latest Neopixel lights arrived. They are on a strip of 8x32 pixels on a flexible pcb. It’s awesome, with power demands that I’m not that happy thinking about. The plan is to do something vaguely “Steam Punk” with them, perhaps involving my recently purchased top hat.

To celebrate I broke out my 10 amp 5 volt power supply. The one that I’ve not dared use yet. Having checked that the power supply produced a vaguely sensible voltage (around 5.5 volts) I tested the Wemos I was going to use (won’t get caught like that again) wired it all together and fired it up.This part of the project should have been the easy bit.

It didn’t work.

In a panic I disconnected the power supply, thinking that I might have wired the positive and negative wires the wrong way round (which is a good way to destroy anything). And suddenly it started working.

It turns out that this is completely normal behaviour. The problem is in the way that the NeoPixels detect their signals. They regard anything above two thirds of their power supply voltage as “true”. If the power supply is 5 volts two thirds of that is around 3.3 volts, which is exactly what the Wemos device produces on its output pins. Happy days.

However, if the power supply voltage is higher than 5 volts the voltage level needed to send a message to the NeoPixels becomes higher than the 3.3 volts that I get from the Wemos and so the communication starts to fail.

So it’s all down to my power supply being too powerful. There are two possible solutions. The first is to use a level converter to boost the signal from the Wemos to 5 volts so that the pixels will react to it. The second is to drop the power supply voltage down to 5 volts so that the maths is in my favour. Ongoing……

Storing Json Configuration Information in devices

I’m a big fan of Json. It is a great way of expressing values in a meaningful way. I’m going to use it to store settings information in our Air Quality sensors. This will make it easy to understand, and extensible. It turns out that it is also very easy to do. I started with an online json editor at https://jsoneditoronline.org/ That helped me come up with this:

{
  "ver":1,
  "wifi": [
    {"ssid":"ssid", "password":"pass"},
    {"ssid":"", "password":""},
    {"ssid":"", "password":""},
    {"ssid":"", "password":""},
    {"ssid":"", "password":""}    
    ],
  "mqtt":{
    "mqttID":"robert01",
    "mqttHost":"mqtt.connectedhumber.org",
    "mqttUser":"connectedHumber",
    "mqttPassword":"pass",
    "mqttPublish":"airquality/data",
    "mqttSubscribe":"airquality/commands",
    "mqttIntervalSecs":60,
    "mqttRetrySecs":20
  },
  "node":{
    "nodeID":"sensor01",
    "noOfPixels":12,
    "pixelColour":{"r":0,"g":255,"b":0},
    "airqSensorType":1,
    "airQLowLimit":1,
    "airqLowWarnLimit":2,
      "airqMidWarnLimit":3,
      "airqHighWarnLimit":4,
      "airQHighAlertLimit":5
  }
}

The json design provides all the information that a sensor needs, including the WiFi settings for 5 different networks. MQTT connection settings and the limits for my warning displays on the coloured pixel.

Next, I needed the C++ to convert the Json into settings that my code inside the device can use to load and store the values when the device runs. It turns out that the Arduino json library has an awesome web page where you can just paste your json and out drops C++ to read and write the values.

I just went to https://arduinojson.org/v5/assistant/ , dropped my Json design into the pate and out came the code. I’ve got to map the settings values onto the variables I’m using in the program, but that is much easier than writing everything from scratch.

This won’t work with the very small Arduino devices because they haven’t really got enough memory to run such large libraries. However, if you’re using an esp8266 or esp32 this really is an easy way to manage internal settings. I’m going to store the json itself using the internal filestore. I’ll post how to do this in a little while.

Test your hardware before you use it

Here’s a little pro-tip that I could have used yesterday:

Test your hardware before you solder it into your device.

I was using a brand new Wemos device that I just took out of the bag, soldered into place and then fired up. It didn’t work. Closer inspection shows that a wayward surface mount resistor has got underneath another component and as a result the board is useless.

I't’s not a huge loss, I’m only paying 2.50 for my Wemos devices at the moment, but it does mean that I have to un-solder the failed device and solder another in place, which is a bit of a pain. From now on I’m going to test my new device just hanging off a usb connector before actually fitting it. Something I used to do, but seem to have forgotten. Of course, the perfect way to do this would be to test all the devices as soon as they arrive from China, that way I might be able to send back faulty ones.

Oh, and the another thing to hold dear is:

Throw away broken devices. They are never worth keeping.

Once it had its moment of glory under my camera, the failed Wemos went straight into the bin. It looks pretty much perfect in every way, and I guess an expert in surface mount technology could do something with it, but I’m not that person, and I don’t want to confuse it with a working one.

Porchlight 2.0

Well, Porchlight 1.0 fell down sometime last night. But no damage done. I’ve switched to a stronger type of adhesive strip and also wedged the light strip into place. I’ve also made an internal version of the lights so that I can test my displays without having to deploy them on the front of the house, which seems like a good idea to me. Now that I’m a bit happier with the power supply I’ve changed to a version of the code that turns on a lot more lights at once, for extra brightness.

Porchlight 1.0

Porchlight 1.0 is up. I’ve discovered that 16mm cable trunking is perfect for holding lengths of Neopixel leds. So I’ve stuck the lights up over the porch using the adhesive foam on the back of the trunking and we’ll see how it goes. I’m using over the air updating so that I can send new programs into the lights without having to go near them. I’m surprised how well that works.

Fun at Hull Makerspace

I spent a very happy three hours at the Hull Makerspace today. I’d been invited to take a look and have a go with the machinery, so I did both.

They’ve got the two most important ingredients just right. Lots of tech and lovely people to help you use it. The tech includes a really nice laser cutter, complete with proper cooling and ventilation systems, which makes it a dream to operate. I took my Hull Pixelbot design files off Github and they were able to feed them straight into the laser cutter and make the robot chassis that you can see above. This of course prompted design work on another version which will be entirely laser cut, rather than needing some 3d printed components. Not that this is really a problem at the Makerspace, they have a couple of 3d printers to play with as well.

It’s that “being next to the machine” immediacy that makes the Makespace such a nice place to work. Knowing that I can turn round a design really quickly means that I’ll be able to experiment a bit. There are also things around the place I’ve never used before, including CNC machine, a lathe, a band saw and a vinyl cutter. Some of them scare me a bit (which is apparently a good mindset to go in with) but I’m really looking forward to finding out how to use them.

Membership will open in the new year. It will cost 10 pounds a month for students and the unemployed and 20 pounds for everyone else. If you want to use some of the more “expensive to feed” devices like the laser cutter there’ll be an extra charge depending on how much you use them, and you will also have to pay for consumables.

For years I’ve been saying “What Hull needs is a really good Makerspace”. Well, we’ve got one now, so it is up to us folks in the region to show just what we can do with it. You can keep track of what they are up to here.

Christmas Lights Taking Shape

Every year I have a plan to make some Christmas lights using Neopixel leds. This year I’ve actually got as far as buying he leds and a power supply unit. Today I spent a happy half hour wiring everything together and a less happy half hour finding out that if you put a series resistor in the data line to the leds (as you are advised to on the web) they don’t work reliably.

Today’s hard won lesson: it’s not always your software that’s at fault. Sometimes the hardware can go wrong too. Once I’ve got the lights working I’ll post a video on here and the code on GitHub. It’s turning out to be quite fun.

Dropmix Review

I usually buy a game at Christmas. This time I’ve bought Dropmix. I saw it on sale at a very attractive price and could'n’t resist it. For the amount you pay you get a lot. There is a handsome plastic console where you pay the game and a set of 70 cards, each of which contains an RFID tag that is read when you play the game and used to trigger the playback of a sample from a music track. The game runs as an app on your phone or tablet which talks to the console over Bluetooth.

You play the game by laying cards down to build up a song. The cards have a characteristic colour and volume level. Coloured cards must be played on the matching colour of the deck and have a louder or equal volume setting than the card they are being placed on top of. Get stuck and you can press a big button which selects a bunch of cards to be removed.

There is a very wide range of music on offer, including Ed Sheeran among others. You can buy themed packs of 15 to get more sounds but they are rather expensive. The cards are nicely made and have artwork that makes them nice things to have before you even play the game. There are also black and white cards that are played to modify the sound.

I was very impressed by how well the samples knit together to make interesting sounds. There are a variety of play modes, including a single player mode, or you can just put cards down to see what you can make. You can even save arrangements that you’re particularly pleased with.

The game is from Harmonix, the people that made a bunch of guitar games. They really know how to make the music fit together, and the gameplay turns out to be a lot of fun. Well worth a look.