USB host

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(Selecting USB host modes: link)
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=== Using USB host mode ===
 
=== Using USB host mode ===
 
==== Selecting USB host modes ====
 
==== Selecting USB host modes ====
 +
'''Please take into account that due to kernel changes sysfs paths can change, if you can't find a particular node, just use the “find” command'''
  
By default, the mini-USB port is in device mode. To tell the Neo that it is logically a host¹):
+
By default, the mini-USB port is in device mode. To tell the Neo that it is logically a host¹:
  
 
  # echo host > [[GTA02 sysfs|/sys]]/devices/platform/s3c2410-ohci/usb_mode
 
  # echo host > [[GTA02 sysfs|/sys]]/devices/platform/s3c2410-ohci/usb_mode
Line 12: Line 13:
  
 
  # echo 1 > /sys/devices/platform/neo1973-pm-host.0/hostmode
 
  # echo 1 > /sys/devices/platform/neo1973-pm-host.0/hostmode
 +
 +
Please note, on my fairly new kernel (andy-tracking commit de8460932576502fb6bf61968a37c4d2aed2d6e2), this node is in /sys/devices/platform/s3c2440-i2c/i2c-adapter/i2c-0/0-0073/neo1973-pm-host.0/hostmode . And from 901d73fe51f33032b34b2ae5612eb863ec90532a Wed Apr 8 commit, usb_mode node is at /sys/devices/platform/s3c-ohci/usb_mode .
  
 
Note: You may want to run <code>ifconfig usb0 down</code> prior to switching to USB host mode, as the Neo's USB networking may not like having its USB port disappear. You'll probably want to ssh into your Neo over WiFi or Bluetooth before starting all of this, alternatively use an on screen keyboard.
 
Note: You may want to run <code>ifconfig usb0 down</code> prior to switching to USB host mode, as the Neo's USB networking may not like having its USB port disappear. You'll probably want to ssh into your Neo over WiFi or Bluetooth before starting all of this, alternatively use an on screen keyboard.
Line 28: Line 31:
 
modprobe ohci-hcd
 
modprobe ohci-hcd
  
* NOTE: with [FSO] based distributions one should use the dbus APIs and not the method stated above.
+
* NOTE: with [FSO] based distributions one should use the [[Dbus device API|dbus APIs]] and not the method stated above.
 +
 
 +
===== Qtmoko v36 (*) =====
 +
As of Qtmoko v36 (kernel 2.6.34-qtmoko):
 +
 
 +
'''To turn on power mode:'''
 +
 
 +
  #echo 1 > /sys/devices/platform/s3c2440-i2c/i2c-0/0-0073/pcf50633-gpio.0/reg-fixed-voltage.2/gta02-pm-usbhost.0/power_on
 +
 
 +
'''To switch to usb host mode:'''
 +
 
 +
  #echo host > /sys/devices/platform/s3c2410-ohci/usb_mode
 +
 
 +
'''To turn off power mode:'''
 +
 
 +
  #echo 0 > /sys/devices/platform/s3c2440-i2c/i2c-0/0-0073/pcf50633-gpio.0/reg-fixed-voltage.2/gta02-pm-usbhost.0/power_on
 +
 
 +
'''To switch to usb device mode:'''
 +
 
 +
  #echo device > /sys/devices/platform/s3c2410-ohci/usb_mode
 +
 
 +
(*)source: [http://permalink.gmane.org/gmane.comp.handhelds.openmoko.community/58783]
  
 
==== Returning to USB device mode ====
 
==== Returning to USB device mode ====
 
After doing whatever is needed to safely remove your device and unplugging it you can remove the provision of 5 volt power and return to device mode.
 
After doing whatever is needed to safely remove your device and unplugging it you can remove the provision of 5 volt power and return to device mode.
  
echo "0" > /sys/devices/platform/neo1973-pm-host.0/hostmode<BR>
+
echo 0 > /sys/devices/platform/neo1973-pm-host.0/hostmode<BR>
echo "device" > /sys/devices/platform/s3c2410-ohci/usb_mode
+
echo device > /sys/devices/platform/s3c2410-ohci/usb_mode
<BR><BR>
+
 
You can now safely restart USB networking.
+
You can now safely restart USB networking
 +
 
 +
ifconfig usb0 up
  
 
==== USB-Mode-Script====
 
==== USB-Mode-Script====
These simple script is useful to switch the USB-Modes:
+
This simple script switches between USB-Modes:
<BR><BR>
+
 
 +
#!/bin/sh
 +
grep -q 'host' /sys/devices/platform/s3c2410-ohci/usb_mode
 +
if [ $? -eq 0 ]
 +
then
 +
echo 0 > /sys/devices/platform/neo1973-pm-host.0/hostmode
 +
echo device > /sys/devices/platform/s3c2410-ohci/usb_mode
 +
ifconfig usb0 up
 +
echo USB-Port is in device-mode now.
 +
else
 +
ifconfig usb0 down
 +
echo host > /sys/devices/platform/s3c2410-ohci/usb_mode
 +
echo 1 > /sys/devices/platform/neo1973-pm-host.0/hostmode
 +
lsusb
 +
echo USB-Port is in host-mode now.
 +
fi
 +
 
 +
See this [https://docs.openmoko.org/trac/ticket/2166 bug] for a justification for adding the lsusb hack.
 +
 
 +
==== USB-Mode-Script (2.6.28+ kernels) ====
 +
The paths change slightly since 2.6.28:
 +
 
 +
#!/bin/sh
 +
grep -q 'host' /sys/devices/platform/s3c2410-ohci/usb_mode
 +
if [ $? -eq 0 ]
 +
then
 +
echo 0 > '''/sys/class/i2c-adapter/i2c-0/0-0073'''/neo1973-pm-host.0/hostmode
 +
echo device > /sys/devices/platform/s3c2410-ohci/usb_mode
 +
ifconfig usb0 up
 +
echo USB-Port is in device-mode now.
 +
else
 +
ifconfig usb0 down
 +
echo host > /sys/devices/platform/s3c2410-ohci/usb_mode
 +
echo 1 > '''/sys/class/i2c-adapter/i2c-0/0-0073'''/neo1973-pm-host.0/hostmode
 +
lsusb
 +
echo USB-Port is in host-mode now.
 +
fi
  
 +
Note: For me (2.6.29-rc3), it is /sys/devices/platform/s3c-ohci/usb_mode ...
  
<nowiki>#!/bin/sh</nowiki> <BR>
+
==== USB-Mode-Script (universal for all kernels) ====
grep -q 'host' /sys/devices/platform/s3c2410-ohci/usb_mode<BR>
+
#!/bin/sh
if [ $? -eq 0 ]<BR>
+
then<BR>
+
USB_MODE=/sys/devices/platform/s3c-ohci/usb_mode
echo "0" > /sys/devices/platform/neo1973-pm-host.0/hostmode<BR>
+
if [ ! -f ${USB_MODE} ] ; then
echo "device" > /sys/devices/platform/s3c2410-ohci/usb_mode<BR>
+
  USB_MODE=/sys/devices/platform/s3c2410-ohci/usb_mode
echo USB-Port is in device-mode now.<BR>
+
fi
else<BR>
+
if [ ! -f ${USB_MODE} ] ; then
ifconfig usb0 down<BR>
+
  echo "Cannot find usb_mode sysfs node"; exit 2
echo "host" > /sys/devices/platform/s3c2410-ohci/usb_mode<BR>
+
fi
echo "1" > /sys/devices/platform/neo1973-pm-host.0/hostmode<BR>
+
echo USB-Port is in host-mode now.<BR>
+
POWER=/sys/devices/platform/neo1973-pm-host.0/hostmode
fi<BR>
+
if [ ! -f ${POWER} ] ; then
<BR>
+
  POWER=/sys/devices/platform/s3c2440-i2c/i2c-0/0-0073/pcf50633-gpio/reg-fixed-voltage.2/gta02-pm-usbhost.0/power_on
You can easily create a push button menu item for this: [http://blogs.thehumanjourney.net/finds/entry/usb_host_mode_the_button Instructions]
+
fi
 +
if [ ! -f ${POWER} ] ; then
 +
  POWER=/sys/devices/platform/s3c2440-i2c/i2c-0/0-0073/pcf50633-gpio.0/reg-fixed-voltage.2/gta02-pm-usbhost.0/power_on
 +
fi
 +
if [ ! -f ${POWER} ] ; then
 +
  POWER=/sys/class/i2c-adapter/i2c-0/0-0073/neo1973-pm-host.0/hostmode
 +
fi
 +
if [ ! -f ${POWER} ] ; then
 +
  echo "Cannot find power hostmode sysfs node"; exit 3
 +
fi
 +
 +
echo "USB_MODE = ${USB_MODE}"
 +
echo "POWER = ${POWER}"
 +
 +
grep -q 'host' ${USB_MODE}
 +
if [ $? -eq 0 ]; then
 +
  echo 0 > ${POWER}
 +
  echo device > ${USB_MODE}
 +
  ifconfig usb0 up
 +
  echo USB-Port is in device-mode now.
 +
else
 +
  ifconfig usb0 down
 +
  echo host > ${USB_MODE}
 +
  echo 1 > ${POWER}
 +
  lsusb
 +
  echo USB-Port is in host-mode now.
 +
fi
  
 
==== Using a GUI ====
 
==== Using a GUI ====
* Using the packaged push button derived from the script above: [http://blogs.thehumanjourney.net/finds/resource/usbmode-button_0.1_armv4t.ipk Download]
+
* Using the packaged push button derived from the script above: [http://blogs.thehumanjourney.net/finds/resource/usbmode-button_0.3_armv4t.ipk Download]
 
* [[User:Techiem2|Mark D. Montgomery II]]'s [http://techiem2.net/index.php?/archives/10-Freerunner-USB-Mode-Control-Program.html application] controls all the various modes through a GUI
 
* [[User:Techiem2|Mark D. Montgomery II]]'s [http://techiem2.net/index.php?/archives/10-Freerunner-USB-Mode-Control-Program.html application] controls all the various modes through a GUI
 
* Thomas Vesely's [http://projects.openmoko.org/projects/usbchmod/ project]
 
* Thomas Vesely's [http://projects.openmoko.org/projects/usbchmod/ project]
 
* Using the gtk+ gui [[Framework-settings]]
 
* Using the gtk+ gui [[Framework-settings]]
* Using openmoko-panel-plugin (confirmation and link needed)
+
* Using [http://projects.openmoko.org/projects/panel-plugin openmoko-panel-plugin]
  
 
=== Providing power to connected USB devices while in host mode ===
 
=== Providing power to connected USB devices while in host mode ===
Line 77: Line 166:
  
 
(please add any known to work)
 
(please add any known to work)
 +
 +
* SIGMA Hub 300 (brandless cheap hub from Czech Makro markets) - can also charge FR, comes with 3.7A adapter
  
 
=== Providing power to run and charge the Neo while in host mode ===
 
=== Providing power to run and charge the Neo while in host mode ===
Line 86: Line 177:
 
Set to 0 (default), no power is provided at the USB port, charging is enabled, and host 15K pulldowns are removed from D+ and D-:
 
Set to 0 (default), no power is provided at the USB port, charging is enabled, and host 15K pulldowns are removed from D+ and D-:
  
echo "0" > /sys/devices/platform/neo1973-pm-host.0/hostmode
+
echo 0 > /sys/devices/platform/neo1973-pm-host.0/hostmode
  
 
Set to 1, provides up to 500mA USB power at the USB port (FreeRunner only), disables charging from USB, and applies 15K pulldowns to USB D+ and D-:
 
Set to 1, provides up to 500mA USB power at the USB port (FreeRunner only), disables charging from USB, and applies 15K pulldowns to USB D+ and D-:
  
echo "1" > /sys/devices/platform/neo1973-pm-host.0/hostmode
+
echo 1 > /sys/devices/platform/neo1973-pm-host.0/hostmode
  
 
Next, power must somehow be injected. An unmodified powered USB hub only provides power to the connected devices, but not to the connected host, so the only solution here is to modify a USB-hub¹) or to create a custom cable which will inject power into the host. See [[specialized_USB_cables]] for some examples.
 
Next, power must somehow be injected. An unmodified powered USB hub only provides power to the connected devices, but not to the connected host, so the only solution here is to modify a USB-hub¹) or to create a custom cable which will inject power into the host. See [[specialized_USB_cables]] for some examples.
Line 105: Line 196:
 
¹) often it's sufficient to short a diode in USB-hub to feed power to the host-connector too.
 
¹) often it's sufficient to short a diode in USB-hub to feed power to the host-connector too.
 
# Edit 05 Oct. 2008 : Not being able to find any diode on my ([[User:Henrikz|Henrikz]]) USB Hub (Brand: Equip, Type: 4 port, aluminum) I simply connected +5V (pin 1) from one of the downstream ports to pin 1 of the upstream port.
 
# Edit 05 Oct. 2008 : Not being able to find any diode on my ([[User:Henrikz|Henrikz]]) USB Hub (Brand: Equip, Type: 4 port, aluminum) I simply connected +5V (pin 1) from one of the downstream ports to pin 1 of the upstream port.
 +
# Another successful mod with images of a DLINK hub (including some caveats) can be seen at [[User:Blutsauger]].
  
 
=== Power Concerns ===
 
=== Power Concerns ===
 
You'll need to force the Neo to go into fast charge mode, since it can't do its usual power negotiation over USB.
 
You'll need to force the Neo to go into fast charge mode, since it can't do its usual power negotiation over USB.
  
echo -n "fast_cccv" >  /sys/devices/platform/s3c2410-i2c/i2c-adapter/i2c-0/0-0008/chgmode
+
echo -n fast_cccv >  /sys/devices/platform/s3c2410-i2c/i2c-adapter/i2c-0/0-0008/chgmode
  
 
(Also this should be done by kernel when seeing 47K at ID-pin)
 
(Also this should be done by kernel when seeing 47K at ID-pin)
Line 117: Line 209:
 
==== USB Keyboard ====
 
==== USB Keyboard ====
  
 +
[[Image:Usb keyboard-jej.jpg|thumb|left]]This [[Usb_keyboard|usb keyboard]] works directly under shr-testing with no changes except usb host device to host
 +
<br clear="both" />
 
Pictures [http://blogs.thehumanjourney.net/finds/entry/20080716 here]
 
Pictures [http://blogs.thehumanjourney.net/finds/entry/20080716 here]
  
Line 138: Line 232:
 
[[Category:Neo FreeRunner Hardware]]
 
[[Category:Neo FreeRunner Hardware]]
 
[[Category:USB]]
 
[[Category:USB]]
 +
[[Category:Power]]

Latest revision as of 19:37, 2 December 2011

The mini-USB port on both the Neo 1973 and the Neo FreeRunner supports both USB host and USB device. This opens up a range of possibilities, such as adding USB cameras and USB input devices.

Contents

[edit] Using USB host mode

[edit] Selecting USB host modes

Please take into account that due to kernel changes sysfs paths can change, if you can't find a particular node, just use the “find” command

By default, the mini-USB port is in device mode. To tell the Neo that it is logically a host¹:

# echo host > /sys/devices/platform/s3c2410-ohci/usb_mode

Independent of the logical mode of the USB port, the Neo FreeRunner can provide 5 volt USB power to an attached USB device. To enable this (not available on Neo 1973):

# echo 1 > /sys/devices/platform/neo1973-pm-host.0/hostmode

Please note, on my fairly new kernel (andy-tracking commit de8460932576502fb6bf61968a37c4d2aed2d6e2), this node is in /sys/devices/platform/s3c2440-i2c/i2c-adapter/i2c-0/0-0073/neo1973-pm-host.0/hostmode . And from 901d73fe51f33032b34b2ae5612eb863ec90532a Wed Apr 8 commit, usb_mode node is at /sys/devices/platform/s3c-ohci/usb_mode .

Note: You may want to run ifconfig usb0 down prior to switching to USB host mode, as the Neo's USB networking may not like having its USB port disappear. You'll probably want to ssh into your Neo over WiFi or Bluetooth before starting all of this, alternatively use an on screen keyboard.

Note that in full USB host mode the FreeRunner will power the external device. To avoid draining the battery use a powered USB hub, then on the FreeRunner enable logical host mode:

# echo host > /sys/devices/platform/s3c2410-ohci/usb_mode

but NOT electrical host mode

# echo 0 > /sys/devices/platform/neo1973-pm-host.0/hostmode

Note that powered USB hubs do not send power upstream, that is, into the host. If you wish to power or charge the FreeRunner, you will need a special USB cable.

¹)Debian note: You'll need the ohci-hcd module: modprobe ohci-hcd

  • NOTE: with [FSO] based distributions one should use the dbus APIs and not the method stated above.
[edit] Qtmoko v36 (*)

As of Qtmoko v36 (kernel 2.6.34-qtmoko):

To turn on power mode:

 #echo 1 > /sys/devices/platform/s3c2440-i2c/i2c-0/0-0073/pcf50633-gpio.0/reg-fixed-voltage.2/gta02-pm-usbhost.0/power_on

To switch to usb host mode:

 #echo host > /sys/devices/platform/s3c2410-ohci/usb_mode

To turn off power mode:

 #echo 0 > /sys/devices/platform/s3c2440-i2c/i2c-0/0-0073/pcf50633-gpio.0/reg-fixed-voltage.2/gta02-pm-usbhost.0/power_on

To switch to usb device mode:

 #echo device > /sys/devices/platform/s3c2410-ohci/usb_mode

(*)source: [1]

[edit] Returning to USB device mode

After doing whatever is needed to safely remove your device and unplugging it you can remove the provision of 5 volt power and return to device mode.

echo 0 > /sys/devices/platform/neo1973-pm-host.0/hostmode
echo device > /sys/devices/platform/s3c2410-ohci/usb_mode

You can now safely restart USB networking

ifconfig usb0 up

[edit] USB-Mode-Script

This simple script switches between USB-Modes:

#!/bin/sh
grep -q 'host' /sys/devices/platform/s3c2410-ohci/usb_mode
if [ $? -eq 0 ]
then
echo 0 > /sys/devices/platform/neo1973-pm-host.0/hostmode
echo device > /sys/devices/platform/s3c2410-ohci/usb_mode
ifconfig usb0 up
echo USB-Port is in device-mode now.
else
ifconfig usb0 down
echo host > /sys/devices/platform/s3c2410-ohci/usb_mode
echo 1 > /sys/devices/platform/neo1973-pm-host.0/hostmode
lsusb
echo USB-Port is in host-mode now.
fi

See this bug for a justification for adding the lsusb hack.

[edit] USB-Mode-Script (2.6.28+ kernels)

The paths change slightly since 2.6.28:

#!/bin/sh
grep -q 'host' /sys/devices/platform/s3c2410-ohci/usb_mode
if [ $? -eq 0 ]
then
echo 0 > /sys/class/i2c-adapter/i2c-0/0-0073/neo1973-pm-host.0/hostmode 
echo device > /sys/devices/platform/s3c2410-ohci/usb_mode
ifconfig usb0 up
echo USB-Port is in device-mode now.
else
ifconfig usb0 down
echo host > /sys/devices/platform/s3c2410-ohci/usb_mode
echo 1 > /sys/class/i2c-adapter/i2c-0/0-0073/neo1973-pm-host.0/hostmode
lsusb
echo USB-Port is in host-mode now.
fi

Note: For me (2.6.29-rc3), it is /sys/devices/platform/s3c-ohci/usb_mode ...

[edit] USB-Mode-Script (universal for all kernels)

#!/bin/sh

USB_MODE=/sys/devices/platform/s3c-ohci/usb_mode
if [ ! -f ${USB_MODE} ] ; then
  USB_MODE=/sys/devices/platform/s3c2410-ohci/usb_mode
fi
if [ ! -f ${USB_MODE} ] ; then
  echo "Cannot find usb_mode sysfs node"; exit 2
fi

POWER=/sys/devices/platform/neo1973-pm-host.0/hostmode
if [ ! -f ${POWER} ] ; then
  POWER=/sys/devices/platform/s3c2440-i2c/i2c-0/0-0073/pcf50633-gpio/reg-fixed-voltage.2/gta02-pm-usbhost.0/power_on
fi
if [ ! -f ${POWER} ] ; then
  POWER=/sys/devices/platform/s3c2440-i2c/i2c-0/0-0073/pcf50633-gpio.0/reg-fixed-voltage.2/gta02-pm-usbhost.0/power_on
fi
if [ ! -f ${POWER} ] ; then
  POWER=/sys/class/i2c-adapter/i2c-0/0-0073/neo1973-pm-host.0/hostmode
fi
if [ ! -f ${POWER} ] ; then
  echo "Cannot find power hostmode sysfs node"; exit 3
fi

echo "USB_MODE = ${USB_MODE}"
echo "POWER = ${POWER}"

grep -q 'host' ${USB_MODE}
if [ $? -eq 0 ]; then
  echo 0 > ${POWER}
  echo device > ${USB_MODE}
  ifconfig usb0 up
  echo USB-Port is in device-mode now.
else
  ifconfig usb0 down
  echo host > ${USB_MODE}
  echo 1 > ${POWER}
  lsusb
  echo USB-Port is in host-mode now.
fi

[edit] Using a GUI

[edit] Providing power to connected USB devices while in host mode

Normally, USB host ports provide power to any connected USB device.

Available power in host mode is the full maximum of 500mA according to USB-specifications on the Neo FreeRunner, and no power is available in host mode on the Neo 1973. If your USB device respects USB-standards and consumes not more than 500mA, you may connect it directly to your Neo FreeRunner.

To provide power to USB devices attached to your Neo 1973, or to provide power to your Neo FreeRunner while USB-device connected, you can provide power by using a (modified [for powering FreeRunner]) powered USB hub (see below), or by manually injecting power into the attached USB device (and Neo FreeRunner) via one of the specialized_USB_cables.

[edit] Powered USB hubs known to work with the Neo

(please add any known to work)

  • SIGMA Hub 300 (brandless cheap hub from Czech Makro markets) - can also charge FR, comes with 3.7A adapter

[edit] Providing power to run and charge the Neo while in host mode

A slightly separate issue is power to run and charge the Neo (both types) itself. When the USB port is in device mode, the Neo FreeRunner/1973 can be powered and recharged via the USB port, but when in standard host mode, the Neo FreeRunner is set to provide power and does not charge. Fortunately, control of the direction of power (in or out) is independent of the personality of the USB port (host or device):

To recap, the direction of power can be controlled:

Set to 0 (default), no power is provided at the USB port, charging is enabled, and host 15K pulldowns are removed from D+ and D-:

echo 0 > /sys/devices/platform/neo1973-pm-host.0/hostmode

Set to 1, provides up to 500mA USB power at the USB port (FreeRunner only), disables charging from USB, and applies 15K pulldowns to USB D+ and D-:

echo 1 > /sys/devices/platform/neo1973-pm-host.0/hostmode

Next, power must somehow be injected. An unmodified powered USB hub only provides power to the connected devices, but not to the connected host, so the only solution here is to modify a USB-hub¹) or to create a custom cable which will inject power into the host. See specialized_USB_cables for some examples.

(However, as there is a wide range[2] of USB hubs out there, one might find power (on a powered USB hub) is available already on the hub's mini USB 5 pin socket already, so not need a specialized cable after all! Check with a test meter.)

Finally, there is the question of charge rate. The charging logic in the Neo will only charge at 100mA by default. Charging at 500mA will take place only if the charging device responds appropriatly to USB negotiation to increase power consumption. Charging at 1000mA will only take place if the Neo detects the appropriate resistor on the ID pins.

You can manually set the charge rate. See Forcing_fast_charge_mode

¹) often it's sufficient to short a diode in USB-hub to feed power to the host-connector too.

  1. Edit 05 Oct. 2008 : Not being able to find any diode on my (Henrikz) USB Hub (Brand: Equip, Type: 4 port, aluminum) I simply connected +5V (pin 1) from one of the downstream ports to pin 1 of the upstream port.
  2. Another successful mod with images of a DLINK hub (including some caveats) can be seen at User:Blutsauger.

[edit] Power Concerns

You'll need to force the Neo to go into fast charge mode, since it can't do its usual power negotiation over USB.

echo -n fast_cccv >  /sys/devices/platform/s3c2410-i2c/i2c-adapter/i2c-0/0-0008/chgmode

(Also this should be done by kernel when seeing 47K at ID-pin)

[edit] Working Examples

[edit] USB Keyboard

Usb keyboard-jej.jpg
This usb keyboard works directly under shr-testing with no changes except usb host device to host


Pictures here

[edit] Connecting a USB-Stick

Connecting-usb-stick-1.jpg

I found this adapter, it has 2 Type A jacks, rather cheap (about 5 €).

Connecting-usb-stick-2.jpg

I borrowed the cable from a card reader, it has the same pinout like the cable that comes with the Neo.

Connecting-usb-stick-3.jpg

With the above commands I could mount the memory stick.

Connecting-usb-stick-4.jpg


Personal tools

The mini-USB port on both the Neo 1973 and the Neo FreeRunner supports both USB host and USB device. This opens up a range of possibilities, such as adding USB cameras and USB input devices.

Using USB host mode

Selecting USB host modes

By default, the mini-USB port is in device mode. To tell the Neo that it is logically a host¹):

# echo host > /sys/devices/platform/s3c2410-ohci/usb_mode

Independent of the logical mode of the USB port, the Neo FreeRunner can provide 5 volt USB power to an attached USB device. To enable this (not available on Neo 1973):

# echo 1 > /sys/devices/platform/neo1973-pm-host.0/hostmode

Note: You may want to run ifconfig usb0 down prior to switching to USB host mode, as the Neo's USB networking may not like having its USB port disappear. You'll probably want to ssh into your Neo over WiFi or Bluetooth before starting all of this, alternatively use an on screen keyboard.

Note that in full USB host mode the FreeRunner will power the external device. To avoid draining the battery use a powered USB hub, then on the FreeRunner enable logical host mode:

# echo host > /sys/devices/platform/s3c2410-ohci/usb_mode

but NOT electrical host mode

# echo 0 > /sys/devices/platform/neo1973-pm-host.0/hostmode

Note that powered USB hubs do not send power upstream, that is, into the host. If you wish to power or charge the FreeRunner, you will need a special USB cable.

¹)Debian note: You'll need the ohci-hcd module: modprobe ohci-hcd

  • NOTE: with [FSO] based distributions one should use the dbus APIs and not the method stated above.

Returning to USB device mode

After doing whatever is needed to safely remove your device and unplugging it you can remove the provision of 5 volt power and return to device mode.

echo "0" > /sys/devices/platform/neo1973-pm-host.0/hostmode
echo "device" > /sys/devices/platform/s3c2410-ohci/usb_mode

You can now safely restart USB networking.

USB-Mode-Script

These simple script is useful to switch the USB-Modes:


#!/bin/sh
grep -q 'host' /sys/devices/platform/s3c2410-ohci/usb_mode
if [ $? -eq 0 ]
then
echo "0" > /sys/devices/platform/neo1973-pm-host.0/hostmode
echo "device" > /sys/devices/platform/s3c2410-ohci/usb_mode
echo USB-Port is in device-mode now.
else
ifconfig usb0 down
echo "host" > /sys/devices/platform/s3c2410-ohci/usb_mode
echo "1" > /sys/devices/platform/neo1973-pm-host.0/hostmode
echo USB-Port is in host-mode now.
fi

You can easily create a push button menu item for this: Instructions

Using a GUI

Providing power to connected USB devices while in host mode

Normally, USB host ports provide power to any connected USB device.

Available power in host mode is the full maximum of 500mA according to USB-specifications on the Neo FreeRunner, and no power is available in host mode on the Neo 1973. If your USB device respects USB-standards and consumes not more than 500mA, you may connect it directly to your Neo FreeRunner.

To provide power to USB devices attached to your Neo 1973, or to provide power to your Neo FreeRunner while USB-device connected, you can provide power by using a (modified [for powering FreeRunner]) powered USB hub (see below), or by manually injecting power into the attached USB device (and Neo FreeRunner) via one of the specialized_USB_cables.

Powered USB hubs known to work with the Neo

(please add any known to work)

Providing power to run and charge the Neo while in host mode

A slightly separate issue is power to run and charge the Neo (both types) itself. When the USB port is in device mode, the Neo FreeRunner/1973 can be powered and recharged via the USB port, but when in standard host mode, the Neo FreeRunner is set to provide power and does not charge. Fortunately, control of the direction of power (in or out) is independent of the personality of the USB port (host or device):

To recap, the direction of power can be controlled:

Set to 0 (default), no power is provided at the USB port, charging is enabled, and host 15K pulldowns are removed from D+ and D-:

echo "0" > /sys/devices/platform/neo1973-pm-host.0/hostmode

Set to 1, provides up to 500mA USB power at the USB port (FreeRunner only), disables charging from USB, and applies 15K pulldowns to USB D+ and D-:

echo "1" > /sys/devices/platform/neo1973-pm-host.0/hostmode

Next, power must somehow be injected. An unmodified powered USB hub only provides power to the connected devices, but not to the connected host, so the only solution here is to modify a USB-hub¹) or to create a custom cable which will inject power into the host. See specialized_USB_cables for some examples.

(However, as there is a wide range[1] of USB hubs out there, one might find power (on a powered USB hub) is available already on the hub's mini USB 5 pin socket already, so not need a specialized cable after all! Check with a test meter.)

Finally, there is the question of charge rate. The charging logic in the Neo will only charge at 100mA by default. Charging at 500mA will take place only if the charging device responds appropriatly to USB negotiation to increase power consumption. Charging at 1000mA will only take place if the Neo detects the appropriate resistor on the ID pins.

You can manually set the charge rate. See Forcing_fast_charge_mode

¹) often it's sufficient to short a diode in USB-hub to feed power to the host-connector too.

  1. Edit 05 Oct. 2008 : Not being able to find any diode on my (Henrikz) USB Hub (Brand: Equip, Type: 4 port, aluminum) I simply connected +5V (pin 1) from one of the downstream ports to pin 1 of the upstream port.

Power Concerns

You'll need to force the Neo to go into fast charge mode, since it can't do its usual power negotiation over USB.

echo -n "fast_cccv" > /sys/devices/platform/s3c2410-i2c/i2c-adapter/i2c-0/0-0008/chgmode

(Also this should be done by kernel when seeing 47K at ID-pin)

Working Examples

USB Keyboard

Pictures here

Connecting a USB-Stick

Connecting-usb-stick-1.jpg

I found this adapter, it has 2 Type A jacks, rather cheap (about 5 €).

Connecting-usb-stick-2.jpg

I borrowed the cable from a card reader, it has the same pinout like the cable that comes with the Neo.

Connecting-usb-stick-3.jpg

With the above commands I could mount the memory stick.

Connecting-usb-stick-4.jpg