I need a very low-cost (50USD for quantity) touch panel running Android OS. I'll use only the LCD, the touch panel and a serial interface (RS485). A USB device port (to make a connection with a PC) and/or USB host port (for connecting USB pen drives) would be nice. The size of LCD could be from 5 to 7".
I don't need SD, Ethernet, WiFi, CAN, RTC, battery, Bluetooth and other nice things. Just a serial interface. And I don't need many features of Android, such as addressbook, phone calls and messages management, TCP/IP and Internet connections, app installation flexibility and similar things.
The final application will be a HMI with good graphics and human interactions (like on Android smartphones).
I know I can use a powerful CPU core module (generally with a SODIMM interface) and design a custom mainboard, but I think the final price of the widget will be higher than my target low price.
I'm ready to design my custom board with MPU and memories, but I need to start at least from a reference design with schematics and software (Android) running well. I don't have the knowledge to hack the Android/Linux kernel.
Any suggestions on a off-the-shelf product or a open hardware design to start from?