There were some requests into forcing the charger controller in the Nooks to allow higher rate charging from non-B&N chargers, I also was constantly annoyed by how my Nooks are always discharging when plugged into my computer with screen on because of only drawing about 500mA, where as the ports would happily provide 1A (development led by Apple).
The work here is experimental and if you decide to try anything, you bear the risk of stuff frying and catching on fire (granted, I did not burn anything here yet, but who knows, this is electricity we deal with here).
The "TRM" is here for anybody interested, sadly it does not match with what the hardware actually does in some important areas (also reflected in the driver comments). It looks like there is no real way to control the charging rate much, as soon as you write into draw rate register, it's two lowest bits are reset to 0 until D+/D- detection is performed, but then the detection resets draw rate back to appropriate defaults, huh? So this leaves us with two settints: 100mA or 1.2A
Plus there's something else going on, e.g. all of my iPhone chargers that I happen to have around only provide about 1.5 Watts of power and the controller refuses to draw more than 500mA from it anyway. All the Android stuff chargers I have on the other hand work out of the box and allow Nook to draw about 1.2A from them (even the native charger does not seem to draw more than this, about 7.5W according to my Kill-a-Watt display and also according to the battery current rate reported by the battery).
Anyway, I am providing two kernels, kernel for Nook HD+ and kernel for Nook HD
Flash the appropriate one for your device.
Then there's the control app: NookChargerControl.apk
Run the app, and it will present you with the main switch at the top (ignore the second switch, it's from the earlier experimentation and currently does not do anything).
If you flip the switch on, the charging is forced at 1.2A rate, no matter where you are connected (but see my earlier note about my iPhone chargers).
In addition to whatever physical measurements you are making, thee are two clues displayed about stuff:
The registers 00 and 08. When register 00 is 0x34 - that's indication of 1.2A, 0x32 = 0.5A, 0x30 = 0.1A, 0x37 should be 3A (When connected to power).
Also a battery-reported current is shown, this is your main clue about how much power does the battery really gets, negative values = discharging.
Tap anywhere on the screen to refresh the values, the battery rate reported sometimes takes several seconds to update, so do not panic if the values appear to be stuck for some time.
If you decide to try this, please report back in the thread with your findings.
In my testing, enabling the switch (while plugged into a computer) results in as much battery charging current as I am getting from B&N charger.
The work here is experimental and if you decide to try anything, you bear the risk of stuff frying and catching on fire (granted, I did not burn anything here yet, but who knows, this is electricity we deal with here).
The "TRM" is here for anybody interested, sadly it does not match with what the hardware actually does in some important areas (also reflected in the driver comments). It looks like there is no real way to control the charging rate much, as soon as you write into draw rate register, it's two lowest bits are reset to 0 until D+/D- detection is performed, but then the detection resets draw rate back to appropriate defaults, huh? So this leaves us with two settints: 100mA or 1.2A
Plus there's something else going on, e.g. all of my iPhone chargers that I happen to have around only provide about 1.5 Watts of power and the controller refuses to draw more than 500mA from it anyway. All the Android stuff chargers I have on the other hand work out of the box and allow Nook to draw about 1.2A from them (even the native charger does not seem to draw more than this, about 7.5W according to my Kill-a-Watt display and also according to the battery current rate reported by the battery).
Anyway, I am providing two kernels, kernel for Nook HD+ and kernel for Nook HD
Flash the appropriate one for your device.
Then there's the control app: NookChargerControl.apk
Run the app, and it will present you with the main switch at the top (ignore the second switch, it's from the earlier experimentation and currently does not do anything).
If you flip the switch on, the charging is forced at 1.2A rate, no matter where you are connected (but see my earlier note about my iPhone chargers).
In addition to whatever physical measurements you are making, thee are two clues displayed about stuff:
The registers 00 and 08. When register 00 is 0x34 - that's indication of 1.2A, 0x32 = 0.5A, 0x30 = 0.1A, 0x37 should be 3A (When connected to power).
Also a battery-reported current is shown, this is your main clue about how much power does the battery really gets, negative values = discharging.
Tap anywhere on the screen to refresh the values, the battery rate reported sometimes takes several seconds to update, so do not panic if the values appear to be stuck for some time.
If you decide to try this, please report back in the thread with your findings.
In my testing, enabling the switch (while plugged into a computer) results in as much battery charging current as I am getting from B&N charger.
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