From: spiglia2 <sp...@ny...> - 2010-11-06 02:05:01
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Dear group. Looking for some guidance on subject ... getting USB Host to work (Overo J4-32,33,34,35) on a custom Overo expansion board. We're using the Tobi as our basline USB Host connection back to a Linux PC (terminal), then switching-over to our custom setup. Initially we had not had VBUS connected as this is a self-powered application; we're only using USB Host for the console connection during system integration. Our initial cut at this had the custom expansion board connected to USB OTG (Overo J1-36, 37) and no connection to USB Host. Now via a custom Gumstix Breakout Board we've direct-connected a USB type A to mini cable to the J4 pins. VBUS is there from the PC terminal as observed via breaking-out leads and viewing on a scope, but DP & DM are dead; no signals observed on scope, no terminal activity. This breakout scheme was validated on the Tobi, so we believe the cable works. Looking at Tobi schematic we've observed some overload protection, ESD protection, and dual-choke. There's also a power switch in series with the VBUS line from the mini-jack controlled via GPIO_168 ... CPEN (not sure of full name) which I believe has to do with the OMAP enabling/disabling or providing a Tobi reset for the port? Our expansion board currently does not replicate these Tobi features, and we've observed that the Pinto USB connector interface is fairly straight forward. Looking for some pointers on diagnosing a dead USB Host from Overo. Thanks in advance, Steve NY -- View this message in context: http://old.nabble.com/USB-Host-problems-on-custom-expansion-board-tp30146461p30146461.html Sent from the Gumstix mailing list archive at Nabble.com. |