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Ask HN: Most interesting tech you built for just yourself?

1901 points l2silver | 1 comments | 27 Apr 23 15:04 UTC | HN request time: 0.241s | source

Maybe you've created your own AR program for wearables that shows the definition of a word when you highlight it IRL, or you've built a personal calendar app for your family to display on a monitor in the kitchen. Whatever it is, I'd love to hear it.
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sriram_malhar ◴[28 Apr 23 06:47 UTC] No.35738249[source]▶
My MIL is 93, and the only tech she can really deal with is turning on the radio and TV and changing channels.

She is fond of music from old classics (from the 60's and earlier), so I hooked up a Raspberry PI with an FM transmitter and created her own private radio station. She tells me what songs she likes and I create different playlists that get broadcast on her station. It preserves the surprise element of radio, and there is nothing in there she doesn't like.

The tiny FM transmitter is surprisingly powerful. Her neighbours (of similar vintage) are very happy too, so their requests have also started coming in :)

EDIT: I wanted to add that I am the UI ... she doesn't get to choose the playlist. To make my life easier, I just created different playlists for different times of the day ... calm/spiritual/slower numbers in the early and late hours, peppy during the late morning and evening etc.

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sandreas ◴[28 Apr 23 07:39 UTC] No.35738587[source]▶
Cool.

For the others: You don't even need a transmitter to do some experiments, you can use just one IO Pin for this:

https://nerdiy.de/en/raspberrypi-send-fm-signals-by-gpio-pin...

Furthermore, you can use something like https://volumio.com/en/ build an RFID Box https://pilabor.com/projects/labelmaker/#products-to-build-t... (my daughter used this when she was 2 years old)

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runjake ◴[28 Apr 23 16:47 UTC] No.35743841[source]▶
Any clue how powerful the "one IO pin" approach is compared to a dedicated FM transmitter?
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1. svnt ◴[28 Apr 23 17:03 UTC] No.35744063[source]▶
A standard 3.3V GPIO can typically push something like 30 to 60 mW. You won’t get all of that as transmitted signal — it will depend on how well your random antenna wire matches the impedance of the gpio and the frequency. I’m really not sure the audio quality is going to be anything more than just intelligible, but I’d guess you’d get at least 10 mW or so of useful power, which means it should generally work within a small house.