Strange behavior of AN87216 (Successful data transfer only through a usb hub)

[Anonymous]

I've been facing strange issues with AN87216 and the streamer application. I'm using the firmware provided for the AN87216 and the streamer application in a windows environment. I can ONLY transmit data successfully when the Slave or Master (either one of them) is connected through a USB hub, if I connect both the Master and Slave directly to a port in the PC the data transmission FAILS (even I tried connecting the Slave and the Master in different PCs without a USB hub, still it FAILS. ONLY works when connected through a USB hub). I don't understand the logic behind this.

If someone can enlighten me on this issue it would be great.

[ManaskantD_51]

Try programming the slave first and then master. Ideally it should work with and without hub.

[Anonymous]

Thanks for the reply.

Still I couldn't get it to work without the use of a hub. If you can give me an insight on the logic behind why programming the slave first? It would be really helpful.

Regards

[ManaskantD_51]

The only logic is that if the master is programmed first, it may start sending or receiving invalid data due to spurious signals on the GPIOS of the slave device as it is not programmed.