St-b-l475e-iot01a 100Hz accelerometer

AssKicker · December 23, 2020, 1:10pm

Hi,

i recorded some datasets to train the AI (accelerometer 100Hz). After building the software i downloaded the compiled firmware for my st-b-l475e-iot01a board. But when i tried to run the software i got an stack overflow error. Am i doing something wrong? I think so hole process is working for dataset recorded with 62.5 Hz.

Greats
Ralf

AssKicker · December 23, 2020, 1:38pm

I tried to update the C++ Lib Version in my mbed project. Compiling and flashing showed the same error.

janjongboom · December 23, 2020, 2:31pm

@AssKicker if you change this line:

github.com

edgeimpulse/firmware-st-b-l475e-iot01a/blob/290b8efe6c6432b1255725b711b4e2f3d975f4ad/source/main.cpp#L50


static BlockDevice *full_bd = BlockDevice::get_default_instance();
static SlicingBlockDevice fs_bd(full_bd, 0x0, 6 * 1024 * 1024);
SlicingBlockDevice temp_bd(full_bd, 6 * 1024 * 1024, 8 * 1024 * 1024);


static LittleFileSystem fs("fs", &fs_bd, 256, 512, 512);
EdgeWsClient *ws_client;
EventQueue main_application_queue;
EdgeSampler *sampler;
DigitalOut led(LED1);


static unsigned char repl_stack[4 * 1024];
static AtCmdRepl repl(&main_application_queue, sizeof(repl_stack), repl_stack);


static WiFiInterface *network = NULL;
static bool network_connected = false;


// this lists all the sensors that this device has (initialized later on, when we know whether
// sensors are present on the board)
static ei_sensor_t sensor_list[2] = { 0 };


static bool microphone_present;

to read:

static unsigned char repl_stack[8 * 1024];

Does this mitigate the issue? There shouldn’t be something that big be allocated on the stack though, will investigate.

AssKicker · December 23, 2020, 11:40pm

Updating the stacksize helped. But its a little bit curious.

janjongboom · December 24, 2020, 9:37am

Yep, will investigate.

janjongboom · December 24, 2020, 12:38pm

Underlying issue was that for accelerometer data on this board we were allocating the raw data buffer on the stack (which is 4K), leading to a stack overflow when your window is more than a few seconds. Fix will land in the patch release next week!

Thanks again for reporting @AssKicker!

AssKicker · December 24, 2020, 3:43pm

Cool, thanks for the fast support.
And merry Xmas