Bike dashcam from RaspiTV

It’s that time of year again: Pi Towers is locking its doors as we all scoot off into the night to spend some time with our families. There will be a special post on Christmas Day for people who have been given a new Raspberry Pi and need some pointers for getting started. Normal service will resume when we’ve dealt with our New Year headaches: until then, have a wonderful Christmas holiday!

Our good friend Alex Eames has been live-blogging a new project over the last week or so, and has just wrapped up. (Seasonal pun. Not sorry.) He’s recently been bitten by the cycling bug.

I’ve ridden about 1100 miles in the last 6 months and have learned enough to bore you to death with talk of heart zones and various items of clothing you can buy to make winter rides more bearable.

Here is Darth Alex demonstrating fashion-forward winter 2018 cycling wear.

Moving swiftly on.

Alex has been working on a dashcam for his bike, mostly intended for use as a rear-view “mirror”, but also to work as an evidence-collecting camera in case of any accidents.

dashcam test

This is really one of the most interesting and enjoyable project write-ups we’ve come across in a while: working on this dashcam as a daily live blog means that Alex has been able to take us down all the rabbit holes he investigated, explain changes of direction and dead ends, and show us exactly how the design and engineering process came together. And this, being an Alex project, has great attention to detail; he made custom mounts for his bike to keep everything as unobtrusive as possible, so it looks great as well.

There’s a ton of detail on hardware (which went through several iterations before Alex settled on something he was happy with), software, implementation, unexpected hiccups, and more. And if you’re someone who would rather skip to the end, here’s Alex’s road test.

I really hope we’ll see more write-ups like this one in 2019. We don’t get to read as much about other project makers’ process as we’d like to; it’s really fascinating to get a glimpse into the way someone else thinks about and approaches a problem.


alex eames avatar

Thanks for blogging this Liz. I had a lot of fun with this project. I was only saying to Albert the other day that I’m not sure how many people really like ‘warts and all dev’ blogs, but I find them really interesting.

I’d certainly like to see more of them too. The process, changes of direction, discovering the ‘unknown unknowns’ etc. can be more interesting than ‘the product’.

Hope everyone at Pi Towers has a fantastic Christmas holiday :)

Liz Upton avatar

Thanks Alex! All the best to you and the family too; I hope you have a wonderful Christmas.

JBeale avatar

Nice demo video. It looks to me like the camera has a fairly close focus setting, such that traffic mostly doesn’t quite come into focus before it passes by. Perhaps that’s intentional if you’re most interested in the frame just before a collision, but otherwise I’d try adjusting the focus somewhat further away. Happy Holidays!

alex eames avatar

You’re right JBeale, the (unofficial) ZeroCam could do with a bit of a focus tweak. I wish they would factory set them at the hyperfocal distance rather than ‘selfie’ distance. (The world has become a bit too self(ie)-obsessed). :)

Dougie Lawson avatar

Most of the videos that make it on to the website’s “Near Miss of The Day (NMoTD)” are done with helmet cams facing forwards. I think you’ll get a better view of the “white van man” who’s out to kill you that way.

alex eames avatar

You really have to not just ‘view the video’ to find out where I’m coming from with this. Its main purpose in life is as an electronic rear-view mirror and it does that job WONDERFULLY well :)

I’ve also put a front camera on last night (feature creep FTW).

There’s something about helmetcams (or putting LEDs/Lights etc. on the cycle helmet) that I find distinctly unappealing. If you fall off or crash, you might find you’ve redefined embedded electronics.

The ideal ‘rear-view mirror’ would be some kind of head-up display (e.g. something like Google glass) but even that might be risky having something so close to the eye(s).

AndrewS avatar

If you ever get the chance, ask Simon Long about his Bluetooth-enabled cycle helmet… ;-)

bsimmo avatar

Is that the Locally or similar smart helemt Simon has, or a homebrew effort?

Ignoring helmet debates, I don’t like the idea of mounting lights and cameras to them, that stick out, they will go right through the helmet and into your head if you’re unlucky. I don’t mind the integrated versions, as that’s not a few extra inches of rigid pointy stuff and I’ve no need to shine a torch into someone eyes when I look up.

That and my helmet is to protect me from scratches and bruises from low lying branches and they would be ripped off.

So what next for feature creap (and yes I like build threads)?

alex eames avatar

Step 1 feature creep has already happened. I’ve added a front camera.
What next? I’m not really sure if I’ll do anything more to it, but there’s a tonne of things that COULD happen…

* accelerometer triggers autosave on ‘crash’
* on ‘crash’ convert latest .h264 file to MP4 and upload to cloud
* data overlay (GPS, speed, time, date etc.)
* read ANT+ data from heart/cadence sensors and overlay data
* live streaming (via phone hotspot)
* trying official cameras with or without additional lenses

Lots of possibilities, but none of them are ‘necessary’. It already does what I built it for really, really well.

bsimmo avatar

Locally = Livall after autocorrect

bsimmo avatar

Google AIY/Alexa/Etc with BT mouthpiece for hands-free control.

GPS overlay and time – on a crash for location evidence would be good feature creep :-)

bill avatar

what did you use as a power supply

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