https://github.com/hishizuka/pizero_bikecomputer

Reminds me of the time when somebody added up the costs of all the parts to a Buick. Why buy $24,000 worth of parts when you can get them all assembled into a car for $8,000? (or whatever the numbers were)

I got it one piece at a time and it didn’t cost me a dime

More than just open source. We need a Linux based bogger that will show them how we play!

I am a big fan of NON-PROPRIETARY software...

Here's a photo of one.



Raspberry Pi Zero for size, which costs $15 right now, plus a small LCD. Works with power meters.

I get it that factory built, sold at retail, bike computers are pretty good for most people but sometimes you need or want something that the marketplace doesn't produce at any
price so rolling your own is a great option,

Looks pretty nice. Seems to match the capabilities of the 520.

The navigation is basic. No generated turn-by-turn.

The cost of parts is probably reasonable. It’s using a dongle for ANT. The BOM for the Garmin units is probably low too. (The real cost to the developer is his time anyway.)

I wonder what the power consumption is like.

For example, in theory anyway, you could substitute an energy-efficient e-ink display for the one shown here if battery longevity is very important for you for something like bicycle touring.

How's about using more than one device synced with each other? An e-ink device for showing turn-by-turn directions as well speed and heart rate alongside a larger-screen color tablet displaying a map for those moments you really need to look at one as well as for planning or changing a ride as you go?

Problem is, going down this rabbit hole, those e-ink displays intended for the Raspberry Pi are apparently fragile. You shouldn't place pressure on the glass is a common refrain I've discovered although I didn't look far and wide enough to see if this will always be true. I almost forgot to mention that the refresh rates on these can be quite slow. The specs for one seven-inch color display indicated a refresh time of twenty-five seconds.

I just picked up an Amazon Fire HD 8 lacking a GPS but can be made to work with an external bluetooth GPS receiver. Why not have one of these theoretical e-ink bike computers do double-duty as this GPS receiver?

Infinite possibilities !