SensorTile.Box hangs when logging acceleration data to SD card

[KBerg.1]

I am trying to log acceleration values, time and date over a longer period of time. (8 hours)

After an undefined time (often after about 1h) the green LED will no longer flash. If the SensorTile.box is supplied by a power supply, you can see that the SensorTile.box consumes about 40mA continuously in this state.

In this state the app can also no longer connect to the SensorTile.box.

The following settings were used in expert mode:

Firmware: 3.4.1

Low power acceleration sensor:

• Acquisition time (minutes) = 480
• - Low Power Mode 1
• - 12.5Hz
• - no LP Filter
• - no HP Filter
• - full scale 2g

RTC date

RTC time

File to SD card (buffer 10k)

Streaming on BLE shows the same behaviour.

Streaming to USB works over the hole period

Does anyone have any idea what could be causing this?

Thanks in advance

[Eleon BORLINI]

Hi @KBerg.1​ , when you download your SD card logging app on your ST.box, do you disconnect the BLE communication with your smartphone or do you leave it connected? Is it possible you are running out of memory on SD card (this should not be the case, but you may check the dimension of the resulting csv file)? And, last question, when you stream to SD card or BLE, do you rely only on the onboard battery for the ST.box power? Consider that in the case of the USB stream you have also the additional charging of the USB itself... Btw, we will perform some tests next days, to try to reproduce your issue. Regards

[KBerg.1]

Hi Eleon,

I tried both, stay connected and disable Bluetooth on the smartphone as well with the same behavior.

If I choose

• High Performance Mode instead of Low Power Mode
• and a sampling rate of 100Hz,

recording runs until the scheduled end.

For our evaluation we can go ahead with this workaround,

Thanks for your support

best regards

Klaus

[Eleon BORLINI]

Hi @KBerg.1​ , so basically the acquisition get stuck when using the Low power mode and not the High performance mode (always 480 min acquisition time)? Regards

[KBerg.1]

Hi Eleon,

Correct, in high performance mode, it also works with other time recording lengths.

I also tried 120 and 240min.

regards