Digital cameras: Canon EOS, Powershot, Nikon DSLRs and P&S, as well as generic PTP.

USB to serial converters: FTDI, PL-2303, ACM, as well as certain cell phones and GPS receivers.

Game controllers: Sony PS3, Nintendo Wii, Xbox360.

HID devices: keyboards, mice, joysticks, etc.

The following device classes are supported by the shield: The shield is TinkerKit compatible, which means you can quickly create projects by plugging TinkerKit modules onto the board. The Arduino USB Host Shield is based on the MAX3421E ( datasheet), which is a USB peripheral/host controller containing the digital logic and analog circuitry necessary to implement a full-speed USB peripheral or a full-/low-speed host compliant to USB specification rev 2.0. It's really a problem since the data lines are common, meaning unless I look at the data byte-by-byte and compare it to the standard, I have no clue what's coming from the host and what's coming from the keyboard.The Arduino USB Host Shield allows you to connect a USB device to your Arduino board. I might be able to use some jumper wires, one of my Unos, and the serial monitor to record what happens from my keyboard and my laptop and then just repeat that verbatim, but if someone knows a more proper way to do it that would be better. I know there's some kind of handshake and addressing I need to do, but what exactly it is is a mystery to me.

However, the problem is, I don't know WHAT to bang out. I don't care about special peripherals, I just want to be able to use a USB keyboard or gamepad and since those are standardized, and normally use low-speed mode, it should be possible to just ignore all the error checking and device identification and just hard-code 'the only devices that will ever be hooked up are an HID ASCII keyb and an gamepad, ignore everything else'. I've been reading up on the USB standard, which is dense as hell and not well explained no matter where I try to read about it, and it oughta be doable. USBTiny gives a decent start on how to do it, but in current form it's just a low-speed peripheral and not a host.

I think it's theoretically possible, although I'm beginning to think it'd be easier to do directly from the 2560 instead of the 16u2 since it's more powerful (especially since mine's also got a 128k bank-switched RAM expander) and doesn't require any irreversible jumper-cable reflashing. I wanna use a Mega R3 as a USB host without extra hardware.

Arduino usb host shield mega amazon