I have an Acer Iconia Tab A500 with stock Honeycomb 3.1, and a Google ADK. I haven't been able to get the ADK to communicate with the tablet in Accessory mode, and I can't find any information that states whether the tablet supports this mode.
I've contacted Acer support, but I have not received a satisfactory response (they misunderstood me and answered that it supports USB Host mode, and haven't responded to my request for more accurate information)
Update: In addition to the information below, I received an official response from Acer technical support:
This issue was sent to our engineers. The unit currently does not support USB Accessory mode; however, we are planning to release an update that adds this functionality. Unfortunately, we are unable to determine when this update will become available. I apologize for the inconvenience.
If I receive any followup indication that they've implemented support I will post it here.
Presently it does not, but we have been in touch with Acer about this issue and a fix is forthcoming.
I can confirm that the ADK DOES NOT work with the Acer A500 running 3.1. However, the Acer A100 running 3.2 does. Hopefully when the A500 gets a 3.2 update things will work properly.
I spoke with Acer Support and the guy said that they support the ADK and it should work with 3.1. Said if your having issues, call 1-800-571-2237, (Monday to Friday 8 am to 8 pm CST)
3.2 ROMs do support accessory mode - I have got the demokit example working using "Taboonay 2.0" ROM, you can find instructions in the xda-developers forum.
来源：https://stackoverflow.com/questions/6863555/does-the-acer-iconia-tab-a500-support-accessory-mode