This is great, I just saw your post on X. I'm also building a bike computer!

eInk is the right display tech. I think this will do really well. It might need a UV filter.

That said, I don't love needing a separate device (hence, I don't own any bike computer). This is just my preference, but I really prefer to just plop my phone on my handlebars. So I'm building a bike computer app for iPhone: https://x.com/mholt6/status/2090529441944687087 (trying to get Apple to approve my developer account / business info, but they're hung up on my website of all things).

Phones are definitely not ideal in terms of display and energy use, but, I have found that with proper optimizations, energy use is a non-issue. To offset display problems, the app has several ride modes: a rich map display with 3D road or satellite view; a high-contrast wireframe map that looks great at both high and low refresh rates because it has no analog-style gauges; an instrument panel dashboard view; and a voice-only mode that has big touch zones for on-demand voice updates, using a state of the art mobile voice synthesis model. For connected radars, the app also renders radar data and has a screen like Tesla/Rivian's autonomy displays.

The app automatically manages thermals by switching modes to preserve battery life.

In my testing so far, by managing energy, making really good voice feedback, and using high-contrast screens (every mode other than the "rich" map), even a dimmed iPhone display is quite a usable bike computer in high-altitude sunlight.

But man, that eInk looks so clean and nice. Definitely the superior display! Nice work and I hope to learn some things from it!

EDIT: Woah, you got ANT+ support using BLE radio? I am not surprised that that is possible, but dang, that must have been a clever LLM.

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robot_jesus 3 hours ago | parent | next [-]

To each their own and the e-ink computer is a neat project. But I'm personally with you on not wanting a separate device. I have my iPhone and a quad lock case I swap on for rides.

Not sure I'm 100% on board with the visual style of your interface (some of the metrics look like they'd be nearly impossible to read while riding 30mph down a gravel road) but I'd love to check it out once it's released.

Do you have a way to sign up for release email or updates for your project?

Good luck!

	▲	mholt 2 hours ago \| parent [-]
		Thanks; not yet unfortunately, I have been too busy to set up a mailing list, but that's a good idea. The video preview I linked to only shows the rich maps and instrument modes. There's also a wireframe map view that is higher-contrast and much more practical for your gravel rides: https://i.imgur.com/lZF20Xz.png -- and I am still tuning of course, we can make the map smaller and the characters larger, etc. Maybe follow @mholt6 on X for updates when I have them... whenever Apple will let me in.

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mmooss 2 hours ago | parent | prev [-]

> eInk is the right display tech.

It's interesting and I clicked on the OP, but why? The variable ambient light conditions, refresh rate, etc would seem to favor standard LCD/etc.

Battery capacity isn't much of an issue for a small screen, and weight carried by the bicycle.

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usern20260720 15 minutes ago | parent | next [-]

LCD screen are pitch black by default. Eink can be white without extra energy

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Gualdrapo 2 hours ago | parent | prev | next [-]

In my humble experience the gold standard for bike computer screens was the Wahoo Elemnt Roam 2. It had like 64 colors or so but you could see it everywhere.

That being said, seeing that there are now eink displays capable of 60Hz, I wish they (and projects like this one) could take over in this specific market.

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mholt 2 hours ago | parent | prev [-]

eInk is like a piece of paper, which gets MORE visible in the sun, but standard touchscreen LCDs/OLEDs get harder to see. I am not sure about the physics/reasons for this. Phones also aggressively dim screens to conserve energy and lower temperatures. Phones absorb a lot of sunlight, so a white eInk display is brilliant in that regard.

Refresh rate is a solved problem for eInk as well, but it comes with energy tradeoffs and... might still be proprietary. But 60-120 fps eInk exists AFAIK.

	▲	WillAdams an hour ago \| parent [-]
		Trying to outbright the sun on a battery-powered device is an approach I've always found questionable. E-ink, instead just lets the sun reflect off of it, does want some sort of light in the dark, but, perfectly visible in full-bright/direct sunlight.