Hacker News Reader

I got annoyed with unlocking my ebike with an app every day, so I created a car key enclosure with a Bluetooth chip to unlock it. So much work! Creating a custom PCB, writing software for the nRF52 chip, learning about BLE, security levels, GATT. Deep sleep and ultra low power usage. I use it every day and am really happy with it.

View on HN

Sounds really cool, do you have a write-up of it anywhere?

https://blog.waleson.com/2022/03/the-worlds-first-cowboy-key...

Source code here: https://github.com/jtwaleson/cowboy-bike-remote-ble

I’m currently working on finalizing the PCB version, the first one had some flaws so the battery drained really quickly.

Thank you. I just recently discovered the nRF52 as a potential solution for my own BLE project. To use a keyfob as a housing is brilliant and very 'stealth'. I have no experience with the nRF52 chips, but this will be a very useful resource for me.

In your blog post you mention that "switching between 24km/h and 25km/h" is very important. May I ask why? Isn't such a speed difference almost negligible as you easily surpass it when pedalling?

If you ever get stuck don't hesitate to reach out :)

There is EU regulation to limit the bike to 25km/h. If you look at the code you can see how the switching between 24 and 25 km/h works. The rest I leave as an exercise to the reader.

Reply on news.ycombinator.com