Can background data logging run without creating a custom App on Banglejs2?

[wwilmajonsson]

Hi!

We’re working on a time-limited school project where we are going to collect sensor data (heart rate and steps) from the Bangle.js2 watch during a full day in a normal daily environment.

Our intended workflow is:

• Connect the watch to a computer in the morning
• Let it collect data in the background throughout the day
• Reconnect it in the evening and export the stored data file

Our question is:

Is it possible to run code in the background without creating a custom app?
For example, by uploading code to RAM or Flash using the Espruino IDE or App Loader (“Upload Code”).

We specifically need the code to:

• continue running all day
• keep logging even when Bluetooth is disconnected
• write data reliably to Storage
• survive screen off / watchface / idle states

So the main thing we need to know is:

Do we absolutely need to build a proper Bangle.js app in order to achieve background data logging, or is there any method to run such logging code without making an app?

Any clarification would be greatly appreciated. Our project is on a tight schedule, and we’re trying to find the simplest reliable solution.

Thank you!

[thyttan]

Hi!

Any js file you name with the scheme placeholder.boot.js on the watch storage will run everytime the watch resets, letting you run stuff in the background.

[gfwilliams]

As @thyttan says, you can just write a file to Storage with the IDE and a filename xxx.boot.js and you're good.

However if you just want to log heart rate and steps to storage, that's all built in! Just install the Recorder app: https://banglejs.com/apps/?id=recorder

You can set it to record HRM and Steps (but not GPS), turn on recording and you're good to go. Recording every 10 seconds might be overkill so every 60 could be better. If you click the floppy disk icon in the app loader it'll even allow you to download the information as a CSV file.