Show HN: Send me an IRL message and watch it arrive

[GSGBen]

https://hi.benren.au/

- This page is running directly on the Pico W in the stream, using microdot (but proxied out via cloudflare tunnel).

- There's a buzzer that plays a sound as well but the stream has no audio.

- There's a Pi Zero 2 W with a Camera Module 3 streaming the video. Streaming low latency video is painful. I tried mjpeg, Nginx+HLS/DASH, YouTube and Twitch. Twitch is definitely the easiest and best-performing.

- There's still a few seconds delay between sending your message and the video updating.

[forgotthetimer]

(OP, temp user, forgot to disable the HN procrastination timer)

For anyone trying to do this in the future, here's the command to stream from a modern Pi camera module / driver to twitch. IIRC I also had to install the full version of the libcamera tools to use the libav switches.

    libcamera-vid -v 0 -t 0 --codec libav --libav-format flv -o "rtmp://<twitch stream url>/<twitch stream key>" --rotation 180 --width 1920 --height 1080 --framerate 30 --bitrate 4000000 --autofocus-mode auto --autofocus-window 0.25,0.15,0.5,0.5

[forgotthetimer → forgotthetimer]

Update: there's been a bunch of great messages so far, from people all over. But most importantly we've had a

    ');DROP TABLES;

[scrps → forgotthetimer]

Make a few model tables and have a lever on a servo push the tables off the desk upon DROP TABLES.

[tehlike → forgotthetimer]

Did it work?!

[GSGBen → tehlike]

Haha nope!

[jbit → forgotthetimer]

Check out the `--shutter` option for `libcamera-vid`, it allows you to tweak the camera's exposure time which might help with the screen refresh banding. `--shutter 60` sets the exposure time to 60ms, which might be a good starting point.

EDIT: Ah, actually the unit is microseconds, so `60000` would be 60ms

[GSGBen → jbit]

Hey thanks, this was a good catch. `--shutter 12000` fixes the screen, and is bright but not too bright.

[GSGBen → forgotthetimer]

Update 2: The servo's gears are absolutely grinding at the moment

[vachina]

You need to increase the camera’s exposure time (integration time) and decrease the ISO. Could barely see the screen.

[tamimio]

I send it and only partial parts showed, I think the camera recording the steam is on a different Hz than the screen, out of sync, could not see it properly.

[globalnode]

your other game project 'grab n throw' looks hilarious, what made you think of that? its like a funny 3d version of pong (without stuff coming back)

[GSGBen → globalnode]

Hey, thanks! I was thinking about game ideas while stepping into the shower one day (where all great ideas are born), and "throwing people in a first-person view might be fun?" came across my mind. I mentally fleshed it out a bit, and wrote it down. When the idea I was already working on turned out to not be fun, I shelved that and started working on this instead. When I prototyped the basic throw feel and it already felt fun, I decided to run with it.

[globalnode → GSGBen]

having them fall down with all that ragdoll physics is the best part, also crashing into crowds like bowling balls. anyway, best of luck with it all, seems like a really original and entertaining idea.

[gus_massa]

Should I see in the video the text that I had sent?

I see only the hand moving.

[forgotthetimer → gus_massa]

Yep, it should show on the screen but unfortunately the camera refresh rate is out of sync with the screen's refresh rate so it's a bit hard to see. I need to read the datasheet again and drop the screen's refresh rate - I tried adjusting the camera's instead but it was never quite right.

[gus_massa → forgotthetimer]

Can you cheat and just repeat the same letter a few times, like "Hello!!!" -> "HHHeeellllllooo!!!" or it shows a dark frame between leters?

[forgotthetimer → gus_massa]

Getting the data onto the screen is fine, and IRL I can't see any flicker, but the OLED screen itself is apparently refreshing at something like 107 or 133 Hz.

[liminalsunset → forgotthetimer]

One way to potentially resolve this is to place the setup in a darker place and/or add a piece of tinted transparent material in front of the camera. The camera will automatically adjust the shutter speed (not the frame rate) because of the reduced light to 1/30 or so which will allow more of the screen to be captured.

[tamimio → forgotthetimer]

Ah, just seen your comment, try to use obs and adjust the rate from there before streaming it.

[averageRoyalty]

Ooh, a .au. Don't see them often in the wild.

Down now, but sounded interesting!