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A Raspberry Pi-powered live train station sign

balena.io

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Re: A Raspberry Pi-powered live train station sign

#101
post #83
post #82

Earlier quoted context omitted.

Rather than show red, why not show the next train you could actually catch? A bit more glass half full, and reduces the light count by 33%!

I was using a physical RGB LED so there wasn't much extra bandwidth for conveying information. I live in a cold climate so green really meant "Leave now and you'll only have to wait in the cold at the stop for 2-3 minutes". Here's the code if anyone's interested[1]. Looks like my memory wasn't quite right, I did blue/green/red with blue=wait, green=leave, red=missed. [1] https://gist.github.com/kevana/32bfa486d9fb0aa…

Ah ok, I envisioned a screen with train info and a traffic light.

Re: A Raspberry Pi-powered live train station sign

#102

Hey folks, balena.io founder here, just chiming in to mention that Chris is one of our Hardware Hackers in Residence, and if you think that doing HW projects with all sorts of cool technologies and writing them up for the world is your dream job, we're hiring! https://balena.workable.com/j/27A101659C Happy to answer any balena (or train station sign) related questions, of course :)

That job looks amazing and makes me wish I wasn’t terrible at soldering.

Thanks so much for Etcher, btw - it’s the only GUI software for flashing Pi images to SD that I’ve had good luck with on Mac.

Re: A Raspberry Pi-powered live train station sign

#103
post #78

I love it! Now you just need to make a platform announcement addon: https://www.youtube.com/watch?v=5Qa7KL1VScw&t=70

I have done exactly that! (but not for London): https://www.youtube.com/watch?v=Fte7w0r8d_k

(Not my video; someone made it using the program I made)

Re: A Raspberry Pi-powered live train station sign

#104
post #54

Why I can't use my old phones to do this is beyond me. I have one windows phone lying around and a few android phones. Everything is there in a neat package but the manufacturer make it so hard to tinker with them.

Blame the rise of the app store. The old Windows Mobile phones were fully open and work just fine for what you want; write your app, load it onto the phone, and just launch it.

Once did a project like this that grabbed Seattle's realtime data for some bus stops around my place. It was an old Windows CE PocketPC thingy, so the tools were primitive (.NET compact framework 1.0, basically).

Maybe a bit too primitive. It worked pretty well for about a year, until I found that the CompactFlash WiFi adapter was only 802.11b and there was nothing newer available that was compatibility with the PocketPC. It ended up being a choice between keeping the gadget running, or being able to run my WiFi network at 802.11g speeds with modern (WPA) security, so the latter won out.

Re: A Raspberry Pi-powered live train station sign

#105
post #15

Very cool but I find a pi is overkill for something like this. ESP8266 or ESP32 would work just as well.

On the other hand, it is also overkill to learn how to program and deal with an ESP32 if you already know some light linux sysadmining and some high level programming language to set this up.

No, it's not overkill. Using the std Arduino IDE and all libraries available to it, it's basically just a development platform like any other.

The catches are a) you don't have a lot of memory, and b) you have to watch little flickering LEDs to know if your app installed correction.

Re: A Raspberry Pi-powered live train station sign

#106
post #41

Earlier quoted context omitted.

ESP32 can run μPython which should make it quite a bit easier for those that know some high level programming language. For me using an ESP32 seems like the more reliable, secure, easier and faster solution but people have their preferences and I relate to it being a bit scary at first.

A restricted port of a language isn't the same thing as the full language. On a Raspberry Pi, you have access to POSIX, system libraries, filesystems, package managers, etc... μPython is fine, but typically a programming language is about more than just the language.

> On a Raspberry Pi, you have access to POSIX, system libraries, filesystems, package managers, etc

All things you basically don't need for a little project like this.

Re: A Raspberry Pi-powered live train station sign

#107

I'd love to see a writeup of doing something like this but without any of the balena cloud stuff.

Hey - I wrote the original code that was forked (exquisitely, I should add!) by Balena. The original code is just a Python script.

I haven’t written it up into a blog yet, but everything to get you started is on my GitHub at https://github.com/chrishutchinson/train-departure-screen. Very happy to help answer any questions too

Re: A Raspberry Pi-powered live train station sign

#108
post #11

Earlier quoted context omitted.

They would, but the Pi Zero is a much better UX for people who don't deal with microprocessors on a regular basis. It has SSH, I can get in and look at logs from my desktop, wifi is standard. It all adds up - and for something like this, the power draw is not an issue, and the cost is minimal.

This is the hardware equivalent of bloated webpages HN tends to dislike :P

Using the PI Zero over an ESP doesn't negatively impact the experience using it. Whereas a very bloated website is going to be slow to load and use. I think there is a significant difference.

Re: A Raspberry Pi-powered live train station sign

#109
post #25

Earlier quoted context omitted.

This is the hardware equivalent of bloated webpages HN tends to dislike :P

It is - but the same applies to a lot of webpages - would people create them if they had to lovingly handcraft every html tag on a page? :)

I still do all/most of my html css js by hand in Notepad++, @davchana at Gitlab. Yes, just a hobby, but still.

Re: A Raspberry Pi-powered live train station sign

#110
post #5

Earlier quoted context omitted.

A Solari Split-Flap Display? I love that they're making new ones! Starbucks has been putting them in their Reserve Roasteries. I'm also sort of happy with the 'modern' ones that are actually LCD screens with speakers making the noises. It's cheating, but it's a nice tribute.

There is something to be said for these kinds of vestigial remnants of technologies past. I've always been fascinated by them, and in fact this kind of thing in computer folklore -- for example parts of the docs that explain something exists "for historical reasons" -- are one of the things that got me into programming. For example the "size_t" size has pretty funny origins which I'll leave as an exercise to the read…

If you're ever in my part of the world, you should visit the Connections Museum[1]. It is truly humbling to see how far we've come. At this museum, you can dial a phone, hear the 'thinking' of all the electromechanical switching crossing the room, before the phone starts ringing.

[1] https://www.telcomhistory.org/connections-museum-seattle/

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