RE: Wrong data in the receive buffer USB CDC

Valery — Thu, 14 Feb 2019 08:28:14 GMT

I dealt with this question, I made same "usbd_ble_uart_freertos" example. Thank you very much!

RE: Wrong data in the receive buffer USB CDC

Sigurd — Wed, 06 Feb 2019 11:57:34 GMT

Hi,

You should take a look at how we do the RX buffer handling in the usbd_ble_uart example. But instead of sending the data over BLE as done in that example, you send it back over USB using app_usbd_cdc_acm_write().

Snippet:

static char m_cdc_data_array[256];
#define ENDLINE_STRING "\r\n"

In your cdc_acm_user_ev_handler:

case APP_USBD_CDC_ACM_USER_EVT_RX_DONE:
        {

            ret_code_t ret;
            static uint8_t index = 0;
            index++;
            NRF_LOG_INFO("Bytes waiting: %d", app_usbd_cdc_acm_bytes_stored(p_cdc_acm));
            do
            {
                if ((m_cdc_data_array[index - 1] == '\n') ||
                    (m_cdc_data_array[index - 1] == '\r') ||
                    (index >= (255)))
                {
                    if (index > 1)
                    {
                        
                        NRF_LOG_DEBUG("Ready to send data");
                        NRF_LOG_HEXDUMP_DEBUG(m_cdc_data_array, index);

                            uint16_t length = (uint16_t)index;
                            if (length + sizeof(ENDLINE_STRING) < 255)
                            {
                                memcpy(m_cdc_data_array + length, ENDLINE_STRING, sizeof(ENDLINE_STRING));
                                length += sizeof(ENDLINE_STRING);
                            }


                             ret = app_usbd_cdc_acm_write(&m_app_cdc_acm, m_cdc_data_array, length);

                    }

                    index = 0;
                }

                /*Get amount of data transferred*/
                size_t size = app_usbd_cdc_acm_rx_size(p_cdc_acm);
                NRF_LOG_DEBUG("RX: size: %lu char: %c", size, m_cdc_data_array[index - 1]);

                /* Fetch data until internal buffer is empty */
                ret = app_usbd_cdc_acm_read(&m_app_cdc_acm,
                                            &m_cdc_data_array[index],
                                            1);
                if (ret == NRF_SUCCESS)
                {
                    index++;
                }
            }
            while (ret == NRF_SUCCESS);


            bsp_board_led_invert(LED_CDC_ACM_RX);
            break;
        }