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NOTE: work in progress |
The USB port (5 position mini type B jack) on the Neo 1973 and Neo FreeRunner can be both a USB device or a USB host. The provided cable (5 position mini type B plug to type A plug) is used when attaching the Neo to a USB host.
A specialized cable is required when attaching the Neo to a USB device, which provides a USB type A jack at the end.
(picture)
Alternately, an adapter capable of connecting two type A plugs will allow attaching the provided USB cable to the USB cable that came with the USB device. This adapter is also known as a gender changer.
(picture)
You can now purchase a proper custom-manufacturered mini-A to full-sized A USB adapter from here. This adapter already has Pins 4 and 5 shorted together internally; the unique form factor also makes it very handy and eliminated the need for things like the double USB female adapter trick shown at the bottom of this page.
You can buy [this] ready-made USB A-Type Female to USB Mini-B Type 5 Pin Male Adapter.
A Mini-B to Female-A cable is also available from www.usbfirewire.com.
(picture, as soon as I build it)
Parts list:
Construction instructions:
(TBA)
You can buy [this] ready-made USB Type A Female to Female Gender Changer.
This community provided instruction shows how to build an adapter from a USB socket salvaged from a computer motherboard.
Note that these instructions are provided in the hope that they are useful but without any warranty!
black GND green 0V white 0V red +5V
black GND green 0V white 0V red 0V
when freerunner acts as a device and
black GND green 0V white 0V red +5V
when it acts as a host.
The adapter works with kingston data traveller 4G memory stick and aiptec pencam webcam. However, for some reason (probably the missing 15k resistors at D+ and D-) it did not work with any of the tested USB keyboards or mice:
usb 1-2: new full speed USB device using s3c2410-ohci and address 24 usb 1-2: device descriptor read/64, error -62 usb 1-2: device descriptor read/64, error -62 usb 1-2: new full speed USB device using s3c2410-ohci and address 25 usb 1-2: device descriptor read/64, error -62 usb 1-2: device descriptor read/64, error -62 usb 1-2: new full speed USB device using s3c2410-ohci and address 26 usb 1-2: device not accepting address 26, error -62 usb 1-2: new full speed USB device using s3c2410-ohci and address 27 usb 1-2: device not accepting address 27, error -62
However, if I connect neo to small (unpowered) USB hub
usb 1-2: new full speed USB device using s3c2410-ohci and address 61 usb 1-2: configuration #1 chosen from 1 choice hub 1-2:1.0: USB hub found hub 1-2:1.0: 4 ports detected
and connect the keyboard to the hub then it is correctly recognized:
usb 1-2.3: new low speed USB device using s3c2410-ohci and address 62 usb 1-2.3: configuration #1 chosen from 1 choice input: USB Keyboard as /devices/platform/s3c2410-ohci/usb1/1-2/1-2.3/1-2.3:1.0/input/input13 input: USB HID v1.10 Keyboard [ USB Keyboard] on usb-s3c24xx-2.3 input: USB Keyboard as /devices/platform/s3c2410-ohci/usb1/1-2/1-2.3/1-2.3:1.1/input/input14 input: USB HID v1.10 Device [ USB Keyboard] on usb-s3c24xx-2.3
With the hub I can also use both keyboard and usb memory stick at the same time.
When I unplug the USB hub (with only keyboard connected to it) the power consumption estimate at /sys/devices/platform/bq2700-battery.0/power_supply/bat/current_now decreases from 175000 to 145000 (are these microamperes?).
NOTE: work in progress |
This cable might be necessary for a number of reasons, e.g.
These instructions will show you how to make a cable with 3 ends:
You connect the Data+ and Data- wires of the Neo and the device, and connect all of the ground wires together and all of the +5V wires together. This powers the Neo and the device, while letting the neo talk to the device. You have to connect 2pcs 15kOhm resistors, one from D+ to ground, and one from D- to ground, to comply with USB-spec for hostmode, as Neo is switching off the internal resistors when you enable charging/powering over USB by asserting EN_USBHOST. See schematics, LOCATION:49XX
Just for reference, the USB wires from left to right are:
The Mini_USB-B connector has a fifth pin, the ID-pin. This pin is supposed to be short to ground to signal FreeRunner to enter hostmode. For the Y-cable and enabling external power while in hostmode, you may connect a 47kOhm resistor from ID-pin to ground. This is the same trick the OM-wallcharger uses to signal to FreeRunner it can charge with 1A. Future kernels should switch to hostmode + external power when seeing this 47k resistor.
5 pin USB 2.0 Plug type A to mini USB Plug type B that should include the ID signal, so that you can add the 47kOhm resistor to ID-pin to trigger fast charging