Building a Real-Time HN Display for $15
30 points
3 days ago
| 5 comments
| medium.com
| HN
rcarmo
26 minutes ago
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I love this because it uses UDP _and_ a CYD (Cheap Yellow Display, which is what we hardware nerds have taken to calling these). I have two or three of these around, one as a 3D printer remote, another as a pseudo logic analyzer, and a caseless one that I use as a Micro Python sandbox.

I've been using UDP to send CPU stats for my machines for ages (https://github.com/rcarmo/raspi-cluster/blob/master/tools/se... is a good example), and in modern networks it has become very much reliable (99.99% so on a LAN). Keeping an eye out for UDP on an ESP32 and running Wireguard might be a little power intensive to ever get this running on battery even if it had an e-paper display, though.

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augusteo
3 hours ago
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Nice project. The $15 price point is genuinely impressive for something like this.

I've been curious about e-ink displays for a while but haven't taken the plunge. What's the refresh rate like in practice? And does it actually help you notice interesting posts you'd otherwise miss, or is it more of a fun desk decoration?

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mlhpdx
2 hours ago
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The refresh rate must be something like 20fps when scrolling the text of long posts. I’m not sure and haven’t measured.

While I’m working I glance at it from time to time and get a sense of the wide breadth of conversations going on at any moment.

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cyode
2 hours ago
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Satisfying to see all the payload request and response sizes in bytes not kb.

Q: the display just starts at 0 and increments comment id by 1 every 10 seconds. Has the device caught up to latest? If you power cycle it, do you have to run through all historical comments?

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mlhpdx
2 hours ago
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The zero is just a magic number to indicate grab the newest. So it’s just showing the most recent comments.
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lormayna
1 hour ago
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Why not using MQTT? A Lambda that fetch new comments from HN, parse them into Markdown and push into MQTT; the ESP only needs to subscribes a topic on MQTT and render the messages.
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hyperbolablabla
1 hour ago
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This is awesome. I've been meaning to check out WireGuard for some time, and this project has been inspiring for me. Thanks!
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