USB
From GumstixDocsWiki
This page gathers USB information for configuring, Q&A's etc.
Contents |
gumstix as USB host
Motherboard
- The PXA270 processor, used in verdex motherboards, can act as a USB host at the same time. (The "USB on-the-go" automatically switches according to what you plug into it).
- The PXA255 processor used in the basix and connex motherboards can act as a USB peripheral, but not a USB host.
Product Configuration
gumstix boards needed for USB host, compact flash and ethernet:
Which gumstix boards should be ordered to get USB host, compact flash and ethernet?
1/ Product selection without bluetooth
| Function | gumstix board |
|---|---|
| USB Host, 18-bit LCD & RS-232 Serial & LCD-ready for Samsung screen | |
| 400mhz or faster processor | verdex XM4 motherboard or verdex XL6P motherboard |
| Compact Flash & 10/100 ethernet | netCF-vx expansion board |
| secure assembly | screws & spacers kit |
| power | 5v power adapter |
| USB Host cables | USB A - miniB cable plus a USB A Gender changer. |
| The mini-b end of the usb cable plugs into the console-vx | |
| Temperature rating | All PXA270-based verdex products are rated from -25C to 85C |
2/ Product selection with bluetooth
| Function | gumstix board |
|---|---|
| USB Host, 18-bit LCD & RS-232 Serial & LCD-ready for Samsung screen | |
| 400mhz or faster processor | verdex XM4-BT motherboard |
| Compact Flash & 10/100 ethernet | netCF-vx expansion board |
| secure assembly | screws & spacers kit |
| power | 5v power adapter |
| USB Host cables | USB A - miniB cable plus a USB A Gender changer. |
| The mini-b end of the usb cable plugs into the console-vx | |
| Temperature rating | All PXA270-based verdex products are rated from -25C to 85C |
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Gumstix as a USB device
With the proper expansion card and software setup, currently all gumstix motherboards are capable of acting as a USB peripheral (connected to a PC).
Note: If you want to attach a USB peripheral (a USB drive, a USB mouse, USB webcam, etc.) to a gumstix, you need to use one of the gumstix that are capable of acting as a host.
Can a connex or verdex configuration be powered via a USB cable ?
Gumstix engineering has not tested this method of providing power via USB but suggests that a connex and verdex configuration may be able to be powered from a host computer and a USB cable.
- On the breakout-gs and console-st boards, FB2 is populated with an SMD component - a resistor - that needs to be replaced with a ferrite bead as the FB is supposed to be a ferrite bead to accept USB power.
Note - The ferrite beads tend to be square in cross section. The resistors tend to be fairly flat in comparison.
Note - The resistors have their resistor code written on them as a 3 digit number. You'll see a couple with 103 (10K) and 203 (20K). The ferrite beads have no writing on them.
- The console-vx and breakout-vx boards should come configured with the ferrite bead.
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An old, obsolete version of the PXA255 reference manual, section 4.2 "Bus Powered Device", claims that the PXA255 cannot be used as a "bus powered peripheral", and gives a brief technical reason. But does that reason really apply when connecting it to a typical PC?
Note that this solution is not tested.
Frequently Asked Questions
For more on USB host and verdex, go to the verdex FAQs.
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