0

I was developing a tablet application for controlling a circuit but now i stuck here somewhere.. there are a few options that i think about what to do after this stage. I need 2 usb ports , one for a usb serial converter (namely pl-2303) and other one is a standart flash drive. I tried to use a hub connected to an OTG cable with no luck. When i plug only one of my devices to OTG port they all work but when i plug 2 of them to hub system freeze or doesn't mount my flash drive. I tried 3 different hubs they are not working. Sometimes i made this setup running with an sd card reader instead of flash and a digitus converter instead of pl-2303. Then i though this can be an issue with the USB 1.1 - 2.0 specifications because pl-2303 is a USB 1.1 device and the rest is 2.0. After i realize the realtek wifi module in the tablet is also mounted to a USB port i removed the module to check if i can connect one of my devices to that port. But as usual the wifi driver of the system is controlling this port , so when i try to power up the port, system checks if it can find the realtek module and when it cant detect realtek wireless module just shuts down the port back. While this happens i can see my device is connected to system for a few seconds before the driver shut it down.

So this is the all story. I just need this 2 device to work together. I am waiting for your opinions

The tablet is a ATM 7021 processor based cheap tablet.

Thanks in advance.

Berkan Demirci
  • 1
  • Likely this is a software problem, fixable if you can dig in deeply enough to the system scripts and/or kernel. However, another option (depending on your storage size and speed needs) would be to hang an SD card off a microcontroller which could implement both the USB-serial and something akin to USB mass storage, while appearing as a single USB device. However, the existing USB mass storage driver might not be happy with that, or willing the share the device, until modified. If you can build and run a custom kernel you should ultimately be able to solve it, if not... – Chris Stratton Oct 02 '14 at 14:53
  • Actually i want the user to plug in his flash drive in order to play music files in it. That's where I need that port. So that storage size is not important for me. I just need to get a USB port out for user. – Berkan Demirci Oct 03 '14 at 11:49

0 Answers0