USB CDC speed improvement

[Vishnu Pradeep]

Hi,

Our application sends data to android phones with the help of OTG cables. We are using https://github.com/hariharan-m/Arduino-Android-USB this library in android for communication. But the data speed is very disappointing.  We could get a maximum of 100Kbps in some phones. The data rates were as low as 20kbps.

Device will have a  maximum of 512MB of data. We will be sending it in chunks of 4096 bytes including packet header and CRC. The android application checks for CRC and acknowledge. Device sends the next packet on successful transfer. 

Can anyone please suggest a better way of doing the transfer to android application?

What is the maximum speed of USB data transfer in nRF52840?

Thanks

[prithvi25]

Any updates on this?
I am also getting 20KB/s data rates and I too want it around 200KB/s

[Vishnu Pradeep]

Application level ack for each packet made the transfer too slow. Without ACK we get more than 400KBps

[prithvi25]

do you mean the android application or on the SDK side?