What data can I log?
You can log data from any of the micro:bit inputs; light sensor, temperature sensor, pins, accelerometer, compass, microphone (V2).
Data is logged against time. You can change the time period from milliseconds to seconds, minutes, hours, days or none if you don't wish to log time.
You can log multiple sources at the same time or separately, depending on your program.
Where is the data stored?
The data is stored on the micro:bit (specifically in designated space on the USB chip). If you choose to download or copy it, it may also be stored on your computer. No data is uploaded to the internet or shared with anyone, unless you choose to do this as part of your work.
How do I update the MY_DATA page to see new data?
MY_DATA (the file found on the MICROBIT drive) is only updated each time the micro:bit is physically disconnected and reconnected via USB. New data is added to the bottom of the table, so you may need to scroll down to see it.
How do I delete the data from the micro:bit?
To fully remove any data from the micro:bit, you will need to perform a full flash. This can be triggered in your program (see Delete the data log on the micro:bit)
What is the maximum logging time?
This will depend on the amount of data being logged, the logging interval, the size of the log file and whether you are logging data on battery/USB. For example, logging several sensors at the same time every 100ms will fill up the log quicker than logging one sensor every day. The micro:bit V2 also supports a sleep mode which could conserve use when on battery. An extension is being developed to facilitate sleep mode in MakeCode and MicroPython.
What is the maximum log size?
This can depend on the amount of data being logged concurrently. For example, logging data every 100ms with 1 column of data you might expect ~11,000 entries, and with 2 columns of data ~6000 entries. If the log is full, you will see an error on your device. You can also specify in your code what to do when the log is full.