app_usbd_cdc_acm_write new line char issue

[Jakub]

Using app_usbd_cdc_acm_write method as blow:

char str[51];
char dev_name[NRF_SDH_BLE_CENTRAL_LINK_COUNT][7];
.
.
.
size_t size = sprintf(str,"{\n\"room\": \"%s\",\n\"uuid\": 0x%X,\n\"value\": %3d\n}\n", dev_name[p_ble_ess_c->conn_handle], BLE_UUID_HUMIDITY_CHARACTERISTIC, p_ble_ess_evt->params.humidity.humidity_value);

app_usbd_cdc_acm_write( &m_app_cdc_acm,
                        str,
                        size);

I see following output in Putty. 

Baudrate is correct (115200) + it decodes first part of the message. 

I have no idea why it crashes at new line.

Using UART module I had no such problems.

Deleting new line characters like that:

size = sprintf(str,"{\"room\": \"%s\",\"uuid\": 0x%X,\"value\": %3d}\n", dev_name[p_ble_ess_c->conn_handle], BLE_UUID_HUMIDITY_CHARACTERISTIC, p_ble_ess_evt->params.humidity.humidity_value);

Didn't change much:

It there a character limit for this method?

[Jørgen Holmefjord]

Hi,

Which SDK version are you using?

How did you configure the USBD library? Where are you calling the app_usbd_cdc_acm_write function from?

app_usbd_cdc_acm_write() is an asynchronous function call, could it be that your str variable goes out of scope and is overwritten before the data is output over USB? Have you tried declaring it static, or global?

Best regards,
Jørgen