Problem sending more than 1 data packet to nrf52840 via the virtual serial port using USB.

[Brunelli]

I'm developing using a PCA10059 board and SDK17.0.2 a dongle to communicate from the computer to the sensor, using the dongle as an intermediary for this communication.
For this I am trying to send and receive packets through the virtual serial port, I am based on the usbd_ble_uart example. But I'm having a problem with the writing communication from the computer to the dongle, as the dongle is only receiving the first data packet, later, I don't receive a new APP_USBD_CDC_ACM_USER_EVT_RX_DONE event.
When I close the serial communication and open it again on the computer, I am able to send one more data packet.

1. Has any settings that limit the number of packets the dongle can receive?
2. What checks can I do to find out where the issue is with this communication?

[Marjeris Romero]

Hi Rodrigo,

I am sorry for the late reply. For your use case I think you should try running this project one colleague of mine have made: https://devzone.nordicsemi.com/f/nordic-q-a/53649/need-a-simple-terminal-program-to-communicate-with-ble-uart-service/217898#217898

Since I suppose you would want to use the nRF52840 dongle as a central device while the sensor will be your BLE peripheral.

See how incoming data from the CDC port is processed in the cdc_acm_user_ev_handler().

Best regards,

Marjeris

[Brunelli]

Thanks for the help, I managed to solve the problem now.
I was using the read function this way without setting the size i was getting the message:

 ret_code_t ret = app_usbd_cdc_acm_read(&m_app_cdc_acm,
                                        &m_rx_buffer[1],
                                        sizeof(m_rx_buffer));

 When i changed for a fixed size solved my problem:

ret_code_t ret = app_usbd_cdc_acm_read(&m_app_cdc_acm,
                                       &m_rx_buffer[1],
                                       8);