Hi all,
I need to send data from LPC-Link2 board over USB and read the data on PC as fast as possible. I tried two different methods based on lpcopen 2.12
Method1: cdc_vcom
Modified the example usbd_rom_cdc_vcom.
Pseudo code that sends data:
while(1) {
vcom_write(buffer1, 12);
vcom_write(buffer2, 16384);
vcom_write(buffer3, 16384);
}
On Windows 7 PC, use Python serial module to read.
Method 2: bulk transfer
Modified the example from usbd_rom_libusb.
Pseudo code that sends data:
while(1) {
usb_data_pipe_queue_write(buffer1, 12);
usb_data_pipe_queue_write(buffer2, 16384);
usb_data_pipe_queue_write(buffer3, 16384);
}
On Windows 7 PC, use Python libusb1 module to read.
My test result shows the throughput of Method 1 is larger than Method 2.
Questions about the result:
1. Which method is able to send the data with greater throughput? I was under the impression that Method 2 should do better. But the test result shows the opposite. Can someone please explain?
2. How can I further improve the throughput.
Please help. Thank you very much in advance!
