Why on earth are there extra components on the USB D+/D- lines?! (C2, C4, R2, R3)
Predictably enough, those parts cause high speed mode to fail (hint: high speed USB works at 480Mbps, and a 47pF capacitor has an impedance of 7 ohm at 480MHz). Linux hosts fall back to full speed (12Mbps) mode with a warning message in the kernel log, and Mac OS X hosts totally fail to enumerate the device. The FT2232H datasheet does not recommend adding any part on D+/D-, and the USB signals go directly to the chip. After removing C2 and C4 and shorting R2 and R3, the adapter was correctly recognized on both Linux and Mac. S. _______________________________________________ http://lists.milkymist.org/listinfo.cgi/devel-milkymist.org IRC: #milkym...@freenode Twitter: www.twitter.com/milkymistvj
