The accelerometer seems to always generate an invalid, unreasonably low value for its first data point, at least when used over Bluetooth.
Here's accelerometer data being captured and charted in real time by Bitty Data Logger:
whereas here it is charting data from a micro:bit:
Here are the first few individual accelerometer notifications. As you can see, the first one has crazy values, which is what you see in the chart.
time (ms) x y z
2137 -8.192 -8.62 0
2138 0.017 1.031 0.082
2177 0.015 1.029 0.089
2597 0.015 1.031 0.09
2630 0.015 1.029 0.09
2630 0.013 1.03 0.076
2677 0.018 1.028 0.089
2679 0.013 1.032 0.09
2726 0.014 1.032 0.09
The accelerometer seems to always generate an invalid, unreasonably low value for its first data point, at least when used over Bluetooth.
Here's accelerometer data being captured and charted in real time by Bitty Data Logger:
whereas here it is charting data from a micro:bit:
Here are the first few individual accelerometer notifications. As you can see, the first one has crazy values, which is what you see in the chart.