STEVAL-STWINKT1B: Could not use automode

[anthonyADV]

Hi, 

I'm opening this issue because I log data with STEVAL-STWINKT1B (battery-powered), and I haven’t been able to get the automode feature working as described in the QuickStart Guide. Here are the steps I followed:

1. Formatted my SD card (SanDisk Extreme 256 GB SDSQXCD-256G-GN6MA) to FAT32 with a 32K allocation unit size;

2. Configured the device_config.json file as shown below and copied it to the root directory of the SD card (which appears as “G:” in my system). Based on the config, I expected to get 4 folders with logs (one per acquisition), each containing 30 seconds of data logging, though I’m not totally sure this is the correct behavior to expect?

   

3. Inserted the SD card into the logger;

4. Pressed the RESET button;

5. Pressed the USR button (the green LED started blinking immediately);

6. Waited approximately 3 minutes, which should be enough time for 4 acquisitions of 30 seconds each (i.e., nof_acquisition * logging_period_s = 4 * 30 s).

Result:
When opening the SD card (G:), I only see one folder, DL2_00001, which contains non-empty .dat files.
In G:/DL2_00001/acquisition_info.json, the start_time and end_time show a duration of about 3 minutes, as expected (see below).

There’s also a new config file at G:/DL2_00001/device_config.json (see below), and interestingly, it shows "enabled": false instead of true, "start_delay_s" turns to 1 instead of 0, but all other parameters (nof_acquisition, ..) are the same than G:/device_config.json. That’s why I suspect the logger is reading the config file located at the root (G:/device_config.json), but for some reasons not using the automode as expected.

I also tried two other experiments:

######## 2 ########

I used the exact same parameters for automode as in the Quick Start Guide (see picture below), and repeated steps 1 to 5. For step 6, I waited 5 minutes, which is more than enough (i.e., 7 * 30 = 210 s = 3.5 minutes).

I noticed that a new device_config.json file appears in the acquisition folder: G:/DL2_00002/device_config.json. In that file, "enabled" is set to false, even though it was set to true in the original config at G:/device_config.json.

So it seems the logger does read the config file from the root directory, but for some reason, it modifies certain automode parameters internally, like "enabled" or "start_delay_s". I have no idea why this happens.

######## 3 ########
After repeating steps 1 to 5, I waited until the green LED turned permanently ON (which, to me, indicates a crash ). This time, I got a G:/DL2_00001 folder, but all the .dat files were empty (iis2dh_acc.dat, stts751_temp.dat, etc.), and the folder was missing both device_config.json and acquisition_info.json.

So maybe there’s something I’m missing? Do you see anything I might have done wrong?

Best regards,
Anthony

[SimonePradolini · Accepted solution]

Hello @anthonyADV 

I'm working on FP-SNS-DATALOG2 v3.1.0, so we're in time to solve the issue and include it into the upcoming release.

Can you repeat test 1 with a couple of modifications?

• set "start_delay_s" to 1 instead of 0
• avoid pressing the USR button

I'm expecting automode starting after 1 second correctly.

"start_delay_s" = 0 isn’t a valid value, thus invalidating the automode setup. Furthermore, also pressing the USR button will invalidate the automode. The idea beyond automode is to demand the logging session to the json entirely; so, by pressing the USR button you’re overriding the automatic behavior.

That's a pity I'm not explicitly exposing those limitations in documentation neither implement a workaround in the firmware. If you confirm that modified test 1 is ok, I'll update the Quick Start Guide and the firmware consequently.

You should see a similar result by replicating test 2 without pressing the USR button.

Test 3 is hard to understand: are you aware about the suggested SD card part number in User Manual section SD card consideration? We've never tested with so large SD card; we’re working with a maximum 32 GB SD cards.

Best regards,

Simone

[anthonyADV]

Hello @SimonePradolini,

Thanks again for your help ! I confirm that the modified Test 1 works perfectly (i.e., Test 1 with no USR button press and "start_delay_s" set to 1 instead of 0).

At first, I assumed that setting start_delay_s = 0 could work, but it didn’t, which is why I started pressing the USR button as a potential workaround. Unfortunately, pressing USR turned out to be another factor causing automode to fail.

For those still facing issues (even with start_delay_s >= 1), I’d like to stress the importance of using a previously valid device_config.json. For example, perform an initial logging session without automode (i.e., by pressing USR), which generates a valid device_config.json. Then, reuse that same file later for automode sessions.