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Comment by hugs | Hacker News Reader

I'd be happy to make it for free just for the feedback! My contact info is in my HN bio.

The downside to a motorized display is the cost. Each motor is roughly $1.50 USD. When you include all the other stuff (electronics, 3D printed parts, etc.), it's at about $2/pin. A relatively small 10x20 display (minimum size for a Tetris board, for example) would cost $400 USD just in raw cost.

At retail, that 10x20 board would likely be around $1000 USD. Arguably this is why no one has mass-produced something like this yet. A larger display would just be too expensive to be practical for most people.

BUT!... Like I said, the feedback would valuable to me so am happy to make one for free. Classic warnings apply: it's still a prototype, so supervised play would definitely be required.

View on HN

If OP takes you up on this, DM me and I'll throw you some cash for doing this.

Hey, thanks. HN doesn't have DMs, though. Send me an email or Twitter DM? (Contact info in my HN bio.)

Also interested in contributing. GoFundMe page maybe? You really piqued my interest.

Appreciate the support. You can find my contact info via my HN bio. Or follow @pinthing and/or @hugs on Twitter. (Yes, I need to set-up an alternative to Twitter someday soon...)

I recall learning about that here. It feels obvious to want a 80x24 or larger computer braille display, but as you say that would be prohibitively expensive.

I do hope that research goes into a more cost effective non-mechanical bump map. In a hybrid display, this would be useful for sighted persons too. For example having tactile feedback from the screen on the car's console would let the driver keep eyes on the road. And then of course let's remember that blindness isn't just seeing darkness, plenty of blind persons have enough usable vision that a hybrid display could be quite useful for them too. I know that's all pie in the sky, but the sad fact is the best accessibility technology is built on building blocks that are useful to sighted people. The iPhone's literally life-changing VoiceOver technology is the most striking example that I'm familiar with. It's a shame Apple ditched the haptic technology on their displays.

Would it be possible to use fewer motors to control more pins? 'Stuff Made Here' made a 12-point display using two motors. https://youtu.be/8Au47gnXs0w?t=429

Maybe. It's all a trade-off. At the moment, I'm running to get one version up and running and willing to revisit design decisions when contemplating a version 2. (If I don't do it that way, I'll keep getting sidetracked by cool suggestions like yours and never get V1 done! :)

Thanks so much! I’ve sent you an email.

I would be happy to donate to your efforts for helping the OP out. Thank you kind soul.

would a solenoid solution work? seems like the coils could be wound into holders on the board directly?

Solenoids could definitely work. They might also be cheaper if I wind them myself. I might do that for a future version. Downside is that's more work to wind custom solenoids, which of course I could automate, but then that's more work to build the automation. Easier to start with small off-the-shelf DC gearmotors for now. Off-the-shelf solenoids are a bit too bulky from what I've found. (Although I don't have perfect knowledge of everything that's out there.)

Linear actuators with DC gearmotors have more fine-grained positional control vs plain solenoids. But that could be fixed if I use a tubular linear actuator design that looks like a solenoid. [1]

But at this point it's more important to get something/anything to a V1 and start getting real world feedback.

[1]: https://youtu.be/3PLWTF_6odc

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