Hello!
I am programming BLE with the nRF52840-DK. [Toolchain Manager: v1.3.0, IDE: Visual Studio Code (VSCode), SDK: ncs v2.6.0, window11 pro]
I am integrating NUS central and CDC ACM . My current goal is to send data received via Bluetooth to a PC (PuTTY) through USB.
1. The result shows '[00:00:48.676,879] <wrn> usb_cdc_acm: Ring buffer full, drop 704 bytes,' and I’m curious about the meaning of this. I believe the ring buffer mentioned in the error message is different from the ring buffer (ringbuf1) in my code.
2. Could you also suggest a possible solution?
Below are the debugging results of my code.
[00:00:48.494,873] <inf> cho: --------------------------------------------------------------------------------------
[00:00:48.506,103] <inf> cho: ble_data_received - 108th, 244 bytes
[00:00:48.512,695] <inf> cho: ble_data_received - ring_buf_space_get: 108th, 2048 bytes
[00:00:48.521,148] <inf> cho: ble_data_received - ring_buf_get: 244 bytes
[00:00:48.528,350] <inf> cho: ble_data_received - Sent: 244 bytes
[00:00:48.534,851] <inf> cho: --------------------------------------------------------------------------------------
[00:00:48.545,837] <inf> cho: ble_data_received - 109th, 244 bytes
[00:00:48.552,429] <inf> cho: ble_data_received - ring_buf_space_get: 109th, 2048 bytes
[00:00:48.560,882] <inf> cho: ble_data_received - ring_buf_get: 244 bytes
[00:00:48.568,054] <wrn> usb_cdc_acm: Ring buffer full, drop 216 bytes
[00:00:48.575,286] <inf> cho: ble_data_received - Sent: 28 bytes
[00:00:48.581,726] <wrn> cho: ble_data_received - send_len < rb_len: 216
[00:00:48.589,233] <inf> cho: --------------------------------------------------------------------------------------
[00:00:48.600,463] <inf> cho: ble_data_received - 110th, 244 bytes
[00:00:48.607,055] <inf> cho: ble_data_received - ring_buf_space_get: 110th, 1832 bytes
[00:00:48.615,509] <inf> cho: ble_data_received - ring_buf_get: 460 bytes
[00:00:48.622,680] <wrn> usb_cdc_acm: Ring buffer full, drop 460 bytes
[00:00:48.629,913] <inf> cho: ble_data_received - Sent: 0 bytes
[00:00:48.636,291] <wrn> cho: ble_data_received - send_len < rb_len: 460
[00:00:48.643,646] <inf> cho: --------------------------------------------------------------------------------------
[00:00:48.654,632] <inf> cho: ble_data_received - 111th, 244 bytes
[00:00:48.661,224] <inf> cho: ble_data_received - ring_buf_space_get: 111th, 1588 bytes
[00:00:48.669,708] <inf> cho: ble_data_received - ring_buf_get: 704 bytes
[00:00:48.676,879] <wrn> usb_cdc_acm: Ring buffer full, drop 704 bytes
[00:00:48.684,112] <inf> cho: ble_data_received - Sent: 0 bytes
[00:00:48.690,643] <wrn> cho: ble_data_received - send_len < rb_len: 704
[00:00:48.698,028] <inf> cho: --------------------------------------------------------------------------------------
[00:00:48.709,259] <inf> cho: ble_data_received - 112th, 244 bytes
[00:00:48.715,850] <inf> cho: ble_data_received - ring_buf_space_get: 112th, 1344 bytes
[00:00:48.724,365] <inf> cho: ble_data_received - ring_buf_get: 948 bytes
[00:00:48.731,536] <wrn> usb_cdc_acm: Ring buffer full, drop 948 bytes
[00:00:48.738,739] <inf> cho: ble_data_received - Sent: 0 bytes
[00:00:48.745,147] <wrn> cho: ble_data_received - send_len < rb_len: 948
[00:00:48.752,532] <inf> cho: --------------------------------------------------------------------------------------
- Below is the code related to cdc_acm.
static int cdc_acm_init(void){
int err;
uint32_t baudrate = 0U;
uint32_t dtr = 0U;
if (!device_is_ready(usbd_dev)) {
LOG_ERR("CDC ACM device not ready");
return -ENODEV;
}
err = usb_enable(NULL);
LOG_INF("main - usb_enable>> %d", err);
while (true) {
uart_line_ctrl_get(usbd_dev, UART_LINE_CTRL_DTR, &dtr);
if (dtr) {
LOG_INF("DTR set");
break;
} else {
k_sleep(K_MSEC(100));
}
}
err = uart_line_ctrl_set(usbd_dev, UART_LINE_CTRL_DCD, 1);
err = uart_line_ctrl_set(usbd_dev, UART_LINE_CTRL_DSR, 1);
err = uart_line_ctrl_get(usbd_dev, UART_LINE_CTRL_BAUD_RATE, &baudrate);
err = uart_irq_callback_set(usbd_dev, interrupt_handler);
return err;
}
static void interrupt_handler(const struct device *dev, void *user_data){
// LOG_INF("interrupt_handler");
}
int main(void) {
int main_err;
ring_buf_init(&ringbuf1, sizeof(buffer1), buffer1);
current_rx_buf = &ringbuf1;
/************************* USBD *************************/
main_err = cdc_acm_init();
uart_irq_tx_enable(usbd_dev);
/************************* Bluetooth Central *************************/
bt_conn_cb_register(&conn_callbacks);
main_err = bt_conn_auth_info_cb_register(&conn_auth_info_callbacks);
main_err = bt_enable(NULL);
if (IS_ENABLED(CONFIG_SETTINGS)) {
settings_load();
}
main_err = scan_init();
main_err = nus_client_init();
main_err = bt_scan_start(BT_SCAN_TYPE_SCAN_ACTIVE);
return 0;
}
- Below is the callback code for ble_receive.
static uint8_t ble_data_received(struct bt_nus_client *nus, const uint8_t *data, uint16_t len){
ARG_UNUSED(nus);
int rb_len;
int send_len;
uint8_t buffer[1024];
size_t space = ring_buf_space_get(&ringbuf1);
LOG_INF("ble_data_received - %dth, %d bytes", rx_count, len);
LOG_INF("ble_data_received - ring_buf_space_get: %dth, %d bytes", rx_count, space);
rb_len = ring_buf_put(&ringbuf1, data, len);
if (rb_len < len) {
LOG_WRN("ble_data_received - %dth Current RX buffer full, dropped %d bytes", rx_count, len - rb_len);
}
rb_len = ring_buf_get(&ringbuf1, buffer, sizeof(buffer));
LOG_INF("ble_data_received - ring_buf_get: %d bytes", rb_len);
if (rb_len != 0) {
send_len = uart_fifo_fill(usbd_dev, buffer, rb_len);
LOG_INF("ble_data_received - Sent: %d bytes", send_len);
if (send_len < rb_len) {
ring_buf_put(current_rx_buf, buffer + send_len, rb_len - send_len);
LOG_WRN("ble_data_received - send_len < rb_len: %d", rb_len - send_len);
}
}
LOG_INF("--------------------------------------------------------------------------------------");
rx_count++;
return BT_GATT_ITER_CONTINUE;
}
