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0 pointsstevekemp7y ago0 comments

I did a similar thing, via an esp8266 device and a vibration sensor!

I also automated the display of tram-departures from the tram-stop next to my house with similar hardware.

Otherwise I setup some "wireless buttons" to trigger alerts/actions on my Linux desktop system, and record local temperature/humidity into a time-series database for tracking purposes.

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spuz7y ago

What kind of display did you use for the tram-stop times? I wanted to do something similar but worked out that the cost to update the display every minute was too much in terms of battery life even with an epaper display. Also, it was too inconvenient / ugly to use mains power.

stevekempOP7y ago

A 4x20 LCD, which works because I'm running on mains-power:

https://steve.fi/Hardware/helsinki-tram-times/

I do have a couple of epaper devices, and they would be ideal but for their terribly slow update-time. I like the clock showing Time & Date (or Time & Temperature), and having epaper update every second just isn't possible. Even if it were then I suspect updating so frequently would negate the potential power-saving of using epaper in the first place.

I do have a nice epaper device for showing weather & weather-forecasts, that works on batteries and updates every 20 minutes. But for trams I update departures every 2 minutes.

staz7y ago

Not OP but did a similar project, the display method I used was simply to use 9 led lined up, each representing a stop before mine, to show the current position of the tram.

My idea was based on the top part of this display https://pbs.twimg.com/media/DXGxPtlXkAA0inj.jpg

spuz7y ago

Interesting! That sounds like a really nice low-tech solution. I like it.

BrandoElFollito7y ago

Which buttons did you use?

I was wondering about that as well but I only found the Amazon ones, which either need tricky operations to be usable (the brand-oriented dash ones) or expensive (the Amazon IoT (eom dash button) for 25 eur).

Surprisingly I did not find one on AliExpress

stevekempOP7y ago

For the buttons I first of all wired a button to an ESP8266 device, made it connect to wifi and publish to MQTT and handled it that way.

But when it came to time to setup a lot more of them I realized that would get expensive quickly. SO I cheated. I bought a bunch of 433Mhz-based radio-buttons:

https://www.aliexpress.com/item/OWSOO-433MHz-Wireless-SOS-Bu...

Then I hooked up an SDR receiver to my PC, and handle it that way. I have a 433Mhz receiver for the arduino, which could also decode those transmissions, but I never used it for anything except to prove I could.

There's a pointer to the software and some overview here:

https://blog.steve.fi/decoding_433mhz_transmissions_with_sof...

BrandoElFollito7y ago

Thank you. I was also considering the 433 MHz way and now that I think about it even bought a sonoff bridge :)

I will spend more time on that during summer when the kids are away

j / k navigate · click thread line to collapse

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spuz7y ago

stevekempOP7y ago

A 4x20 LCD, which works because I'm running on mains-power:

https://steve.fi/Hardware/helsinki-tram-times/

I do have a nice epaper device for showing weather & weather-forecasts, that works on batteries and updates every 20 minutes. But for trams I update departures every 2 minutes.

staz7y ago

Not OP but did a similar project, the display method I used was simply to use 9 led lined up, each representing a stop before mine, to show the current position of the tram.

My idea was based on the top part of this display https://pbs.twimg.com/media/DXGxPtlXkAA0inj.jpg

spuz7y ago

Interesting! That sounds like a really nice low-tech solution. I like it.

BrandoElFollito7y ago

Which buttons did you use?

Surprisingly I did not find one on AliExpress

stevekempOP7y ago

For the buttons I first of all wired a button to an ESP8266 device, made it connect to wifi and publish to MQTT and handled it that way.

But when it came to time to setup a lot more of them I realized that would get expensive quickly. SO I cheated. I bought a bunch of 433Mhz-based radio-buttons:

https://www.aliexpress.com/item/OWSOO-433MHz-Wireless-SOS-Bu...

There's a pointer to the software and some overview here:

https://blog.steve.fi/decoding_433mhz_transmissions_with_sof...

BrandoElFollito7y ago

Thank you. I was also considering the 433 MHz way and now that I think about it even bought a sonoff bridge :)

I will spend more time on that during summer when the kids are away

j / k navigate · click thread line to collapse