Today's Forecast: Light Showers, But Brighter Later On

As a British person, I can tell you there two things that you'll hear us complain about more than anything else: the rain, and the trains.

Although in recent years, it certainly feels that the UK generally seems to get nicer weather than we used to, our trains are still worthy contenders for the title of the worst project management known to mankind.

If you're going to go up against an adversary as mighty as Mother Nature, or as confusing (OK, there, I've just given away I'm not a Londoner!), it very much pays to be well informed, and in the information game, there's a lot to be said for up-to-date metrics, presented in a format that's quickly and easily digestible. What's confusing about the Tube, I hear you ask? I mean, it's a bunch of straight train lines, right?

The tube map means well, and serves to simplify the extensive network of underground train services that snake around underneath London city, sprawling outwards to the boroughs and beyond. In reality, this highly stylized set of stations and service lines suggests some non-linear time travel is required when roaming around the capital — after a few trips around the various parts of London, it becomes quickly apparent that some of those lines are not as linear as they seem, nor do their lengths represent the actual distances between the stations...

The Transport For London authority have a lesser known version of the tube map, that matches the meandering paths more closely.

One look at this, and it's clear that there's a bit of an advantage to having oversight of the entire network, when it comes to rerouting your ride home!

While many of us have our favorite phone apps that can signal incoming service disruptions on the circle line, and widgets on our wristwatches for keeping weary eye on the weather, there is something to be said for the more intuitive, visual representation of such data.

Many of these apps will have labeled values, data deemed especially relevant to your geographical location. If you wanted the forecast for further afield, for example, you're left stringing together subsequent search results for various locations. A train tracker will tell you about your delayed, usual route home from work — but in London, being able to quickly remap your route on the fly is a part of city life, and being able to quickly see the state of the many Underground lines means you might be able to make alternative route plans and still make your 9am meeting!

Indeed, some services will be able to show you a graphical, map-based view of the data, but even then, there's still perhaps an unnecessary level of interaction.

Wouldn't it be nice if you could just be presented with such relevant information before you even were to go browsing for it? Maybe something like this luminous likeness to the original, stylized tube map, with the Underground lines that link London, laid out lovingly in LEDs.

I have a feeling that could be the thinking behind the bright idea utilizing a matrix of minuscule LEDs to map out these metrics in a graphical fashion, managing to provide an instantaneous preview of the precipitation, or pointing out the "Planned Engineering Works" that occasionally plague the passengers of the London Underground without needing a push notification.

Having such a high level overview of the Underground is the entire of the Underground is absolutely invaluable. This beautifully laid out set of components would look very much at home, if it perhaps found a fitting frame, and even some frosted perspex would finish this FR4 board off, as a functional furnishing fit for any home.

Should the LEDs signal a broken... signal, or perhaps pulse out a points failure, you'll have ample warning that today's commute might be better served by other, overground means. But perhaps, now you risk getting soaked on your way into the Big Smoke?

Rather than trying to map out your route against the ever fickle forecasts provided the pages of MET Office, piped to your phone, maybe just peek over at this panel of pixillated predictions of the precipitation that might pose a problem as you push on with your daily commute.

Looks can be deceiving — and you might be thinking that there's a bit of a difference in how these displays are configured, when comparing the layouts and densities of the two displays, but they are almost the same circuit.

It doesn't look it, due to the difference in the density of each design, but both boards feature a minimum of a whopping 333 individual LEDs — 338 on the RainTrakr, actually!

The 333 LEDs used on the TrainTrakr allow it to show information about every single train station within the greater London area, while the 338 LEDs of the RainTrakr offer some pretty good resolution — as far as the prediction of rainfall is concerned!

Driving this many LEDs from the relatively few available I/O of the ESP8266 ESP-12E module used in these displays requires some thought, and when tasked with finding a way to address such an array, a Holtek HT16K33 is a fine choice!

Designed as a driver for LED matrices, the multiple segment outputs (16) and column outputs (8) of the HT16K33 allow for a maximum configuration of 128 individual LED positions. With its I2C serial interface, and some neat address pin strapping options, multiple chips can be addressed on a single I2C bus, enabling the incredible number of LED's that we see here on these boards.

Beyond instructing the I2C LED controllers, the ESP-12E is also put to work in providing internet connectivity, allowing the devices to fetch the latest data for their displays. Perhaps a level of execution not often seen in these projects, is the provision of a customer-facing server, that serves up the data that is specifically required by the displays.

It's a level of detail that opens up the potential for a huge wealth of tailored information formatting, with processing of any capacity being performed on a easily configurable server, rather than poking around with the application code residing on the device.

This way of managing devices is common place in consumer IoT goods, so how come we don't see this implemented more often? Perhaps the commitment of providing a reliable service for time to come is a bit daunting at the maker level?

If you're a Londoner, why not take a look at the TrainTrakr over on Tindie? Or if you're more generally based in Great Britain (or just want to laugh at our weather from afar...), the RainTrakr might be worthy of your interest!