Copied from Android Developers web page:
“When your Android-powered device is in USB host mode, it acts as the USB host, powers the bus, and enumerates connected USB devices. USB host mode is supported in Android 3.1 and higher.”
So this means that even if the Lenovo A1 has the native hardware support for USB Host mode, this cannot be used without an update of the Android version of A1 (currently 2.3.4). An upgrade to Honeycomb will be required before we can even test this feature…
On the other hand, this article also from Android Developers mentions that:
“Open Accessory is a new capability for integrating connected peripherals with applications running on the platform. The capability is based on a USB (Universal Serial Bus) stack built into the platform and an API exposed to applications. Peripherals that attach to Android-powered devices as accessories connect as USB hosts.
Open Accessory is introduced in Android 3.1 (API level 12), but is made available to devices running Android 2.3.4 by means of an optional external library, the Open Accessory Library. The library exposes a framework API that lets applications discover, communicate with, and manage a variety of device types connected over USB. It also provides the implementation of the API against parts of the Android platform that are not directly exposed to applications in Android 2.3.4.”
And
“Note: Support for USB host and accessory modes are ultimately dependant on the device’s hardware, regardless of platform level. You can filter for devices that support USB host and accessory through a <uses-feature> element. See the USB accessory and host documentation for more details.”
So this means that Android 2.3.4 supports USB host mode and it is up to the manufacturer to use the appropriate hardware in order for the tablet to feature the USB host mode. I wonder if Lenovo has opted for this…
But a few lines below, always in the same page:
“No USB host support — Android 2.3.4 and the Open Accessory Library do not support USB host mode (for example, through UsbDevice), although USB host mode is supported in Android 3.1. An Android-powered device running Android 2.3.4 can not function as a USB host. The library enables the Android-powered device to function as a peripheral only, with the connected accessory functioning as USB host (through UsbAccessory).
Confusing, isn’t it??
This review from Arpandeb.com mentions that A1 features USB OTG, but I do not know where this infomation comes from…
Information for a DIY USB OTG cable can be found in Chris Paget’s blog.
Information on how to enable USB OTG in a ZTE Blade can be found here.