There is already an FTDI RS232 converter on your board, wired to one of the micro-USB sockets. If the amount of data you want to transfer is moderate, you can use that. You could expect to get 1Mbit/s through such a converted, sometimes a bit more. I don't own such a board so this is just an estimate.

If you need to transfer lots of data and 1Mbit/s, you should run an FTP server, either using WiFi (assuming your Android phone can act as access point) or using Ethernet over USB. For the latter, see if you have a kernel module called g_ether available for your kernel.

There is already an FTDI RS232 converter on your board, wired to one of the micro-USB sockets. If the amount of data you want to transfer is moderate, you can use that. You could expect to get 1Mbit/s through such a converted, sometimes a bit more. I don't own such a board so this is just an estimate.

If you need to transfer lots of data and 1Mbit/s is not enough, you should be using Ethernet over USB. See if you have a kernel module called g_ether available for your kernel.