Possible hardware "Home Keys" for android?
Posted: Sat Aug 20, 2011 11:31 am
Hi all, my first post but I have been following the Joggler Scene for quite some time. It was an expensive nightmare to get one in my hands, but I did it! I am quite happy to be here. I am a pretty experienced hacker and technophile, especially with hardware hacking. I see a lot of great talent on these forums! I must admit though software is my weak point, though I am not code'tarded entirely 
Let me jump straight to the point. I am slightly familiar with how Android handles keyboard input with the On Screen and Physical Keyboard IME platform. Granted Button Savior certainly lives up to its name there is the occasional situation where it falls short. The easiest way to add 'Home' - 'Back' - 'Menu' - 'SoftKey' would be to use a microcontroller on the USB Bus to pass the keyboard scancodes to the OS. A very major issue with that is how Android handles the Keyboard IME. Its a bit dumb. It will assume that the USB MCU is a full keyboard and will not call into action the On Screen keyboard, leaving you with no way to input text beyond what the MCU can do, unless someone here knows of a way around this. I ran into this issue with my Dropad A8X Android tablet and Wiimote bluetooth controller. Until I disabled the Wiimote IME I had no OSK.
During my research I noticed the Joggler has a hard to reach I2C bus. Would it be possible to use a MCU to create a 6-button keypad that will act as physical buttons and pass the key scancodes for Home, Back, Softkey, Menu, and Volume? Does anyone know what those values are for reference? Those buttons could easily be attached to the top/sides of the Joggler, most MCUs support I2C, and being so common a very small MCU can be chosen and fitted to sit inside the Joggler itself with no needed components like oscillator or voltage rectifier. Heck, flatten the legs of a 16 pin DIP chip and there is still plenty of room up by the Wifi card. An 8 pin SOIC chip, granted you isolated it with some heatshrink so nothing shorts, can sit pretty much anywhere.
How does this idea sound, viable, or too complex due to the inner workings of Android?
Let me jump straight to the point. I am slightly familiar with how Android handles keyboard input with the On Screen and Physical Keyboard IME platform. Granted Button Savior certainly lives up to its name there is the occasional situation where it falls short. The easiest way to add 'Home' - 'Back' - 'Menu' - 'SoftKey' would be to use a microcontroller on the USB Bus to pass the keyboard scancodes to the OS. A very major issue with that is how Android handles the Keyboard IME. Its a bit dumb. It will assume that the USB MCU is a full keyboard and will not call into action the On Screen keyboard, leaving you with no way to input text beyond what the MCU can do, unless someone here knows of a way around this. I ran into this issue with my Dropad A8X Android tablet and Wiimote bluetooth controller. Until I disabled the Wiimote IME I had no OSK.
During my research I noticed the Joggler has a hard to reach I2C bus. Would it be possible to use a MCU to create a 6-button keypad that will act as physical buttons and pass the key scancodes for Home, Back, Softkey, Menu, and Volume? Does anyone know what those values are for reference? Those buttons could easily be attached to the top/sides of the Joggler, most MCUs support I2C, and being so common a very small MCU can be chosen and fitted to sit inside the Joggler itself with no needed components like oscillator or voltage rectifier. Heck, flatten the legs of a 16 pin DIP chip and there is still plenty of room up by the Wifi card. An 8 pin SOIC chip, granted you isolated it with some heatshrink so nothing shorts, can sit pretty much anywhere.
How does this idea sound, viable, or too complex due to the inner workings of Android?