Cypress Semi have some USB Host ICs which just might have enough brain onboard to do ADB conversion without needing a second micro, as well as GPIO pins for bitbanging.
Semi-related thread
If not, any of the cheap ARMs with USB host onboard should have plenty enough grunt for this. Using two Arduinos and a separate USB IC sounds like doing it the hard way to me.
If you are just more at home with AVR/Arduino, you can get them with USB host these days, too, and fast. ADB isn't exactly a fast or fat pipe; seems to me like a single micro should be able to handle bit-banging that, USB, and data conversion.
Reading the summary page on the Maxim USB device you linked above:
Semi-related thread
If not, any of the cheap ARMs with USB host onboard should have plenty enough grunt for this. Using two Arduinos and a separate USB IC sounds like doing it the hard way to me.
If you are just more at home with AVR/Arduino, you can get them with USB host these days, too, and fast. ADB isn't exactly a fast or fat pipe; seems to me like a single micro should be able to handle bit-banging that, USB, and data conversion.
Reading the summary page on the Maxim USB device you linked above:
I wonder if you could steal an ADB IC from a broken keyboard or mouse, and use that for the upstream side? Chances are that uses SPI or I2C.