Public transit seats have a rough life. Enduring a number of wear cycles that would make your sofa weep, they take a beating and have to keep looking presentable. When trains and buses are retired, where do the old seats go? A team from the MIT Hobby Shop investigated what was happening to the seats from retiring MBTA Red Line cars and recycled them into stylish chairs.
After some sleuthing and many emails, the MBTA relinquished a number of old subway seats to the team. Since the subway seats didn’t have legs, wood from old church pews was used to create bases. It took one pew end support to create each set of legs, which were cut out on a bandsaw. The old dark stain was sanded off, and the bases were finished with three coats of gel topcoat, letting the natural beauty of the old oak shine through.
We love seeing old things given new life here at Hackaday. If you want to see some more recycled furniture, check out this tire table, this upcycled jeans chair, or these best practices for making box forts.
There was a time, not so long ago, when folks who wanted to make their own custom PCBs would have found themselves in the market for a bucket of acid and a second-hand laser printer. These days, all you have to do is click a few buttons in your EDA program of choice and send the files off for fabrication. It’s easy, cheap, and nobody ends up with chemical burns.
This has obviously had a transformative effect on the electronics hobby — when you can place traces on a PCB like an artist using a brush, it’s only a matter of time before you get projects like [Logan Arkema]’s DCTransistor. This open source board uses carefully arranged RGB LEDs to recreate the Washington Metropolitan Area Transit Authority (WMATA) metro map, and thanks to an ESP8266 connected to their API, can display the positions of trains in real-time.
If you’re getting a sense of déjà vu here, it’s not just in your head. We’ve seen similar maps created for other major metropolitan areas, and [Logan] certainly isn’t trying to take credit for the idea. In fact, he was a bit surprised to find that nobody had ever made one for the DC area — so he decided to take on the challenge himself. He reasoned it would be a good way to hone his PCB design skills and become more comfortable with embedded development. We’d say the end result proves his theory correct, and makes one more city that can boast about its IoT cartography.
Looking to hang a DCTransistor on your own wall? [Logan] says he’ll be dropping the board design files and schematics into the project’s GitHub repository soon, and he also plans on selling pre-made boards in the near future.
We covered this London “tube” map back in 2020, and were impressed by the attention to detail that went into similar displays for Tokyo, Singapore, and the San Francisco Bay Area a year later. Perhaps it’s time to map out your own hometown in LEDs?
Is your love of public transportation matched only by your passion for designing custom PCBs? If so, then you’re going to love these phenomenal transit maps created by [Chai Jia Xun]. Using the painstakingly refined principles outlined in his detailed write-up, he’s created versions for Tokyo, Singapore, and the comparatively spartan San Francisco Bay Area. All you need to make one up for your home town is an incredible amount of patience and dedication. No problem, right?
As [Xun] explains, the first part of creating one of these maps isn’t unlike generating a normal PCB. Just make a footprint for the stations, consult with Google Maps as to where they should be placed on the board, and then connect them all up with traces to stand in for the rail lines. A little silkscreen work, and you’re done.
Well…unless you want them to light up, anyway. To pull that off, [Xun] created a second PCB that places an LED behind each station hole drilled in the previous board. With a microcontroller and shift register, he’s able to selectively illuminate individual lines and run through different patterns. To combat light bleeding through the PCB, a CNC-cut piece of 3 mm MDF sits between the two boards to make sure each LED is only visible through the respective hole in the top surface.
You could call the map finished here as well, assuming you don’t mind all the stations lighting up white. If you want them to be different colors, you’ll need to insert some colored diffusers. [Xun] went through several different approaches here, but in the end, the idea that seemed to work best was to simply print out all the colored dots on a piece of transparency paper and use a second sheet of tracing paper to soften the light. Alignment here is critical, but once everything is dialed in, the results are quite impressive.
It’s quite a bit of work, and we haven’t even mentioned the fact that [Xun] had to modify the circuit when it came time to do the Tokyo map, as some MOSFETs had to be added into the mix for the microcontroller to reliably control 350+ LEDs. So there’s certainly no shame in simply buying one of them when they go on sale instead of trying to recreate it from scratch. Assuming you live in one of the cities he’s offering, anyway. Otherwise, you might want to take a look at our HackadayU class on KiCad and get yourself a comfortable chair.
If you’re a frequent traveler on a public transit system, it can be helpful to know when the trains or buses are arriving and if there are any delays. We might reach for a tablet to mount on the wall, but that relies on keeping the OS, the software, and its library dependancies up to date. For true reliability you’ll need to build directly in hardware, which is exactly what this map of the London tube system uses.
The base map is printed directly on PCB, with LEDs along each of the major routes to indicate the current location of the trains. A few small chips handle the WiFi connection — it appears to our eye to be an ESP8266 — and pulling the information about the trains from the London Underground API (it would be virtually impossible to build everything for this project in hardware). The hardware can be easily reprogrammed, and with the PCB layout this could be adapted for other public transit fairly easily.
Even apart from the philosophical differences on design between hardware and software approaches, we still appreciate the aesthetic of LEDs on PCB. In fact, we’ve seen a whole host of artwork on PCBs ever since the price came down dramatically in the past two decades.
Thanks to [Al] for the tip!