HDMI and USB at same time
Saturday I had some time to open the HDMI dock (for Galaxy Tab 7) and mod it to have alternative power input.
After that I was able to use the HDMI output and USB host at same time. The setup is:
- HDMI out for Samsung TV
- wireless USB keyboard
- external HDD connected with a powered HUB
In this setup I was able to use the keyboard and video files from external HDD while watching on TV screen.
The only problem is that the "MTP Application" notification is still there and the tablet is not full powered from external power supply, it discharges slowly the battery.
After some investigation I've seen that on the original charger there seems to be some resistors between USB lines and Vusb and GND. If I connect the original charger (not inserted on power outlet) the tablet is full powered and the MTP Application is not displayed (when I put the tablet in dock). After that if I remove the cable and insert the USB host cable everything is OK and tablet is full powered with USB host and HDMI working.
The docking is powered with 5V/2A PDA DC adapter.
When I'll open the dock again I will make some picture.
Your are welcome for questions and suggestions.