I'm working on a simple project based on the USB CDC ACM and libuarte example, the chip is nrf52840.
A function is redirect the USB VCP data to another MCU via UART, just like what FTDI's FT232RL do.
When a large packet (6k bytes+) comes from USB, the CDC part split it to 64 bytes packets, then use nrf_libuarte_async_tx function to transfer one by one, the tx queue got full rapidly and data lost.
My question is: how to tx data in synchronize mode?
The related codes:
case APP_USBD_CDC_ACM_USER_EVT_RX_DONE:
{
ret_code_t ret;
size_t iSize = app_usbd_cdc_acm_bytes_stored(p_cdc_acm);
int byteIndex = 0;
do
{
/*Get amount of data transfered*/
size_t size = app_usbd_cdc_acm_rx_size(p_cdc_acm);
uart_txBuffer[byteIndex++] = m_rx_buffer[0];
/* Fetch data until internal buffer is empty */
ret = app_usbd_cdc_acm_read(&m_app_cdc_acm,
m_rx_buffer,
1);
} while (ret == NRF_SUCCESS);
wifi_txBuff(&uart_txBuffer[0], byteIndex);
nrf_delay_us(87*iSize); //HAVE TO WAIT SOME US TO SENT, LOST DATA WITHOUT THIS DELAY
NRF_LOG_INFO("USB received: %d %s", byteIndex, (char*)&uart_txBuffer[0]);
nrf_gpio_pin_toggle(LED_CDC_ACM_OPEN);
break;
}
void wifi_txBuff(char *buff, size_t len)
{
ret_code_t ret = nrf_libuarte_async_tx(&libuarte, buff, len);
if(ret == NRF_ERROR_BUSY)
{
buffer_t buf = {
.p_data = buff,
.length = len,
};
nrf_queue_push(&m_buf_queue, &buf);
NRF_LOG_INFO("uart is busy, queue it.");
}
}
PLS: Tried to use libserial example, TX is ok, but NRF_SERIAL_EVENT_RX_DATA event never triggered for some reason.
