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Root USB peripheral support
- Thread starter colchiro
- Start date
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- Tags
- b&n nookcolor
TheAmazingDave
Android Expert
I love that thread.
I completed v2 of my NC USB host cable. I'll be sure to post pics this time.
I have a USB headset that I have working. The mic isn't quite right but I have strong faith in the NC devs.
I completed v2 of my NC USB host cable. I'll be sure to post pics this time.
I have a USB headset that I have working. The mic isn't quite right but I have strong faith in the NC devs.
TheAmazingDave
Android Expert
Made it out of a generic USB extension cord (for female USB end) and a Nook Classic USB cord. My first design used two female USB connectors with a long-ass male USB pigtail for power.
This is similar, but instead of having the second female USB to receive a standard microUSB-USB-A cable, now the Nook Classic's microUSB connects right to Nook, with a female end instead of male to receive any USB device, and the Nook Classic's USB-A pigtail is used to supply additional power via plug-in USB source or other PC.
This is similar, but instead of having the second female USB to receive a standard microUSB-USB-A cable, now the Nook Classic's microUSB connects right to Nook, with a female end instead of male to receive any USB device, and the Nook Classic's USB-A pigtail is used to supply additional power via plug-in USB source or other PC.
TheAmazingDave
Android Expert
OK 
1 - Micro USB (bottom left)
2 - USB-A Female (bottom right)
3 - USB-A Male, power only, no data (top center)
Connect 1 to Nook's Micro USB.
Connect USB device to 2.
Connect 3 to desktop/laptop or plug-in USB power adapter like Nook's stock charger when necessary.
I've used memory sticks, a hard drive, a wireless mouse, and a USB headset using this adapter, all work great.
1 - Micro USB (bottom left)
2 - USB-A Female (bottom right)
3 - USB-A Male, power only, no data (top center)
Connect 1 to Nook's Micro USB.
Connect USB device to 2.
Connect 3 to desktop/laptop or plug-in USB power adapter like Nook's stock charger when necessary.
I've used memory sticks, a hard drive, a wireless mouse, and a USB headset using this adapter, all work great.
Ok, I see. So you can hook something to the Nook using 1 and 2 like normal, but 3 allows you to supply power at the same time? Does that allow your nook to charge at the same time? Or is it only supplying power to the peripheral? And what if you didn't have #3? Would the peripherals still work? Just would drain the Nook's battery faster?
TheAmazingDave
Android Expert
Several points:
1. Nook can only provide 100mA through its micro USB port. This is only enough to drive the most basic devices like most USB memory sticks, some card readers, headsets, mice/keyboards, etc.
2. Occasionally, a "basic" device will have a high power demand. If the device reports a power requirement greater than 100mA, the Nook will instantly drop the connection to it. This is true even if the device doesn't use as much power as its USB profile suggests. This can be circumvented by connecting an unpowered hub to the Nook, and then plugging your devices in to the hub. The hub will mask the power hungry profile and the Nook will maintain connection. If the device does draw more than 100mA, however, additional power can be supplied to the hub, which should in turn provide the hub with enough power to drive the device.
3. Some high-power USB devices will have their own external power source. Full-size external drives, for instance, will have their own power supply. However, pocket drives (those using laptop hard drives) generally pull power from their host. Nook cannot ever power a hard drive directly.
So, in the case of point two or three, I can use the additional power lead (male USB-A) to make up the lack of current from the Nook.
If I were using a hard drive, for instance, I'd unwind my power lead (keep it bundled up nicely with a rubber band so it's not flailing around when the power lead isn't in use) and plug it into my NC's power adapter. I would then take my hard drive's USB cable, and attach it to the female USB-A connector on my adapter. The hard drive receives power from the NC adapter and spins up. Now, with power and hard drive attached to my adapter, I connect the micro USB to the Nook. USB host must then be enabled using dalingrin's Nook Tweaks or verygreen's USB Host Switcher app. (Nook Tweaks is in the Market, and I have the APK for the standalone USB Host app if you'd like it) If you connect the adapter after enabling the USB Host, and not before, be sure to enable External VBUS! This will be activated automatically if power is present on the USB port when host is enabled. My drive is currently NTFS so the Nook won't mount it, yet, but it does know it's there.
If I were connecting a mouse, the process is easier. I'd leave the power lead bundled up and out of the way, and connect the mouse to the female USB-A connector on my adapter. After enabling USB host, I'd connect the micro USB to the Nook, with the mouse already connected to the other end. Bam! Nook detects mouse and a pointer appears on screen. The process would be the same for connecting a USB memory stick, but you need to mount it via terminal. Automount should be coming soon.
Nook does in fact receive power from this adapter cable. BUT the Nook Color has specific parts that allow it to charge properly only with the NC charger and NC charge/USB cable. The NC cable has extra pins to carry higher current than a standard micro USB cable. This means that although the NC will report that it is charging, it really is not. Without use of the specific 2 amp NC charging circuit, the NC won't charge with my adapter. You may be able to supply it with enough power to slow down battery drain, but it will not charge.
Also, when I made the cable, I left the data pins from the power lead disconnected. The male USB-A lead can only be used to supply power to the bus, it can't be used as a data cable.
1. Nook can only provide 100mA through its micro USB port. This is only enough to drive the most basic devices like most USB memory sticks, some card readers, headsets, mice/keyboards, etc.
2. Occasionally, a "basic" device will have a high power demand. If the device reports a power requirement greater than 100mA, the Nook will instantly drop the connection to it. This is true even if the device doesn't use as much power as its USB profile suggests. This can be circumvented by connecting an unpowered hub to the Nook, and then plugging your devices in to the hub. The hub will mask the power hungry profile and the Nook will maintain connection. If the device does draw more than 100mA, however, additional power can be supplied to the hub, which should in turn provide the hub with enough power to drive the device.
3. Some high-power USB devices will have their own external power source. Full-size external drives, for instance, will have their own power supply. However, pocket drives (those using laptop hard drives) generally pull power from their host. Nook cannot ever power a hard drive directly.
So, in the case of point two or three, I can use the additional power lead (male USB-A) to make up the lack of current from the Nook.
If I were using a hard drive, for instance, I'd unwind my power lead (keep it bundled up nicely with a rubber band so it's not flailing around when the power lead isn't in use) and plug it into my NC's power adapter. I would then take my hard drive's USB cable, and attach it to the female USB-A connector on my adapter. The hard drive receives power from the NC adapter and spins up. Now, with power and hard drive attached to my adapter, I connect the micro USB to the Nook. USB host must then be enabled using dalingrin's Nook Tweaks or verygreen's USB Host Switcher app. (Nook Tweaks is in the Market, and I have the APK for the standalone USB Host app if you'd like it) If you connect the adapter after enabling the USB Host, and not before, be sure to enable External VBUS! This will be activated automatically if power is present on the USB port when host is enabled. My drive is currently NTFS so the Nook won't mount it, yet, but it does know it's there.
If I were connecting a mouse, the process is easier. I'd leave the power lead bundled up and out of the way, and connect the mouse to the female USB-A connector on my adapter. After enabling USB host, I'd connect the micro USB to the Nook, with the mouse already connected to the other end. Bam! Nook detects mouse and a pointer appears on screen. The process would be the same for connecting a USB memory stick, but you need to mount it via terminal. Automount should be coming soon.
Nook does in fact receive power from this adapter cable. BUT the Nook Color has specific parts that allow it to charge properly only with the NC charger and NC charge/USB cable. The NC cable has extra pins to carry higher current than a standard micro USB cable. This means that although the NC will report that it is charging, it really is not. Without use of the specific 2 amp NC charging circuit, the NC won't charge with my adapter. You may be able to supply it with enough power to slow down battery drain, but it will not charge.
Also, when I made the cable, I left the data pins from the power lead disconnected. The male USB-A lead can only be used to supply power to the bus, it can't be used as a data cable.