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Show HN: Open-Source eInk Bike Computer

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Re: Show HN: Open-Source eInk Bike Computer

#71

Post by carlosjobim »

mmooss wrote: post #39
mholt wrote: post #15

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/sta…

> 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.

Because most people cycle outdoors and when the sun shines, and eInk is much better than any other display type in bright environments.

Re: Show HN: Open-Source eInk Bike Computer

#72

Post by carlosjobim »

ianburrell wrote: post #64
mholt wrote: post #42

Earlier quoted context omitted.

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 tradeo…

Transflective LCDs, which most bike computers use, are also reflective but have better contrast than eink making them more visible in sunlight. They are different than phones.

They don't have better contrasts. They have blacker blacks, but eInk has much whiter whites.

Re: Show HN: Open-Source eInk Bike Computer

#74

Post by stingrae »

loeg wrote: post #51
mattlutze wrote: post #35

Earlier quoted context omitted.

This device has a backlight enabled by a physical button, and navi refresh rate doesn't matter because you're riding and not staring at it. 1Hz is fine for a reference. Not sure why needing less battery or having better at-a-glance visibility would be such a bad thing. One need not love a device, that's ok. But digging to invent a reason to hate it also doesn't seem necessary.

Refresh rate does kind of matter. 1Hz imposes an average 0.5s latency on any update, which would be obnoxious in some situations.

i can push it as high as 20Hz.

Re: Show HN: Open-Source eInk Bike Computer

#75

Post by stingrae »

wiether wrote: post #23

I love my eInk displays, I love my bike head unit. But I don't see how they both fit together honestly. The pros of eInk: - low energy usage -> don't matter, current GPS units have +30 hours of battery life already - low eye strain -> don't matter, you don't look at the screen for hours at a time - visibility -> don't matter, current GPS units adapt to ambient light - angle visibility -> don't matter, the screen is r…

refresh rate is sort of a non issue. i can push the refresh rate to up to 20Hz, it is largely unnecessary for this project.

it has a nice backlight (basically identical to a kindle display)

color is fair, but i dont miss it.

i do absolutely love how readable it is in direct sunlight (when im mostly riding)

Re: Show HN: Open-Source eInk Bike Computer

#76

Post by stingrae »

mholt wrote: post #15

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/sta…

note using a phone mounted to a bike or motorcycle can cause damage over time to the camera assembly especially the motors used for OIS. depending on how much you ride or the quality of the roads you ride, it could be an issue.

your project does look amazing. sorry that the appstore team is holding things up.

RE: ANT+, a hackrf one and fable was key to the hack.

Re: Show HN: Open-Source eInk Bike Computer

#77

Post by stingrae »

__d wrote: post #28
tuchsen wrote: post #6

Hey this looks neat, I’ve been thinking on trying something similar. I’ve not encountered the ANT protocol, what bike ya using? Is it a higher level thing that your display is giving you, or something your controller uses? I know Bafang uses CAN protocols in their newer e-bike systems and a lot of manufacturers (especially Chinese) use a proprietary UART protocol to stitch things together on the cheaper end. The mess…

ANT+ is basically dead because of an EU legal requirement to ensure that personal information is encrypted. So no new devices will be supporting it, and everything has to move to BLE. It was quite a rich ecosystem of sensor devices, especially for cycling, including speed and cadence sensors, heart rate monitors, power meters, lights, radar, etc. It has been extremely popular over the last 20 years.

what is insane, is that ble is largely unsecured in modern implementations. when testing, i kept picking up everyones whoops/assorted ble devices spamming out heart rate data to whomever wanted to connect.

Re: Show HN: Open-Source eInk Bike Computer

#78

Post by [deleted] »

jeffbee wrote: post #24

This is cool, but I bet it will be a grind trying to get to Garmin levels of battery life. They just have it nailed, and an Edge 550 that's ¼ this size can run for over a day, despite its emissive display, and they don't seem to suffer from display scaling since the larger Edge 1050 runs for even longer. That is to say that the larger battery in a larger device more than compensates for the higher display power requi…

[deleted]

Re: Show HN: Open-Source eInk Bike Computer

#79

Post by alabut »

mholt wrote: post #15

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/sta…

I use my phone as a bike computer too but it only works on short rides around town. Anything longer gets cooked by the sun until the screen dims and battery stops charging.

That’s why the head units in my bikepacking groups have screens that double as solar displays. The Coros Dura is probably the most popular one for all day or multi-day trips.

Re: Show HN: Open-Source eInk Bike Computer

#80

Post by Brian_K_White »

jeffbee wrote: post #27
monknomo wrote: post #13

Earlier quoted context omitted.

ant+ is a garmin protocol that is very common with fitness gadgets and in the bike world. It's a bit like bluetooth, but lower energy usage.

It also got nuked from orbit by European regulators. The ecosystem has a huge installed base but no future.

Isn't it only using standard ble hardware anyway? So what's the problem?
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