[Q] Nook HD/HD+ connector pinout and serial?

[leapinlar]

This is all very interesting, and some nice pics. I wonder, has anyone attempted (or even considered) to replace the annoying proprietary connector by soldering a replacement micro-USB onto the PCB? Is it even viable?

I can't understand why they would be so daft as to introduce a non-standard connection. Apple can just about get away with it because, well, they're Apple.

A standard micro-USB would not have enough current capacity to properly charge these large devices. On the Nook Color/Nook Tablet, B&N used a customized micro-USB that had a double set of contacts in it. It worked but was very fragile and failed a lot so they abandoned that on the HD/HD+ in favor of the proprietary connector. Samsung also uses a proprietary connector on their tablets for the same reason.

Sent from my BN NookHD+ using XDA Premium HD app

 

[jbbandos]

Any idea where one can buy the connector in europe? I'd like to start playing with it.

 

[Jon Lee]

Yes.
So TX definitely transmits the console output, we see it.
But tryign to input stuff onto RX pin does not result in anything visible, so that's why we are less sure if that's the input into the serial console.
But even if not, the console output is the more important one anyway for my kernel debugging plans.

I dare say you will need to make an adapter similar to this:
slatedroid<dot>com/topic/36069-howto-white-pdn-serial-interface/

The only thing this is good for is to get into u-boot bootloader.

Much easier to purchase a pl2303 usb-serial for kernel or linux work.

 

[timbooo]

A standard micro-USB would not have enough current capacity to properly charge these large devices. On the Nook Color/Nook Tablet, B&N used a customized micro-USB that had a double set of contacts in it. It worked but was very fragile and failed a lot so they abandoned that on the HD/HD+ in favor of the proprietary connector. Samsung also uses a proprietary connector on their tablets for the same reason.

Sent from my BN NookHD+ using XDA Premium HD app

Oh. Thanks!

 

[ro-76]

I opened my Nook HD+, and there is a test point near the dock connector labeled usb-id. If this TP is shorted to GND with a slave USB device attached thru a USB-A to A gender bender, the Nook acts as host as expected per USB-OTG standard. This TP maps to pin 24. Unfortunately, this isn't one of the pins to a Nook HD+ USB cable.

The Nook HD+'s motherboard is labeled EXCELLENTLY. I've gotten most of the pins I can get easily. I think the remaining pins are for HDMI (which makes sense seeing B&N makes an HDMI adapter cable...). The HDMI adapter cable will probably get the remaining pins.

Here's the pinout I've got so far:

Pin - Signal
--------------------------------------
1 - USB VBUS (+5VDC)
2 - USB VBUS (+5VDC)
3 - HDMI 5V
4 - LINEOUT-DTC
5 - USB D-
6 - USB D+
7 -
8 -
9 -
10- GND
11-
12-
13- GND
14-
15-
16- GND
17-
18-
19- GND
20-
21-
22-
23-
24- USB-ID
25- LINE-L (Audio)
26- GND
27- LINE-R (Audio)
28- GND
29- GND
30- GND

---------- Post added at 06:27 AM ---------- Previous post was at 06:04 AM ----------

Also, there are two test points, SDA2-TX and SCL2-RX. These are I2C test points but I can't tell if they are the HDMI side or the system side. The HDMI chip is the TI TPD12s015, datasheet can be googled. Just a hunch that these are the HDMI side, since the datasheet says SDA_B and SCL_B are HDMI side, and they're labeled as SDA2 and SCL2.

Hi

Thank you for this excellent info. I'm trying to build a dock with nexus 7 style 'pogo pins' for charging while in the dock. In order to do that, I need to solder onto +5, GND, USB D+ and D-. I took my nook hd apart and can see some points on the pcb where it would be possible to solder, but can only see GND. I can't see any of the other 3 labeled. Could you point me in the right direction?

Thanks

Ronan

 

[DeanGibson]

HDMI adapter opened

I opened my Nook HD+, and there is a test point near the dock connector labeled usb-id. If this TP is shorted to GND with a slave USB device attached thru a USB-A to A gender bender, the Nook acts as host as expected per USB-OTG standard. This TP maps to pin 24. Unfortunately, this isn't one of the pins to a Nook HD+ USB cable.

The Nook HD+'s motherboard is labeled EXCELLENTLY. I've gotten most of the pins I can get easily. I think the remaining pins are for HDMI (which makes sense seeing B&N makes an HDMI adapter cable...). The HDMI adapter cable will probably get the remaining pins.

Here's the pinout I've got so far:

Pin - Signal
--------------------------------------
1 - USB VBUS (+5VDC)
2 - USB VBUS (+5VDC)
3 - HDMI 5V
4 - LINEOUT-DTC
5 - USB D-
6 - USB D+
7 -
8 -
9 -
10- GND
11-
12-
13- GND
14-
15-
16- GND
17-
18-
19- GND
20-
21-
22-
23-
24- USB-ID
25- LINE-L (Audio)
26- GND
27- LINE-R (Audio)
28- GND
29- GND
30- GND

Using a chisel with a fine edge inserted along the left rear of the plastic case, I pried open a Nook HDTV adapter, with only very minor marring of the plastic package (it was held together with weak glue). I discovered a couple things:

1. It isn't just wires; there's quite a bit of logic in there. There's a "P13HDMI 101-BZHE Y1246GG" 42-pin chip, along with at least one voltage regulator, several transistors, and at least a dozen each of associated diodes, capacitors, and resistors.
2. Pins 26 and 28 on the Nook edge are not grounded in the package, and are presumably shields for the accompanying audio LINE-L/R pins.
3. Pin 24 (USB-ID) on the Nook edge is not grounded or floating, but goes through a (measured 0.0 ohm???) resistor (R17-??, just below transistor Q5), to transistor Q5 and on to other circuitry. For pin 24 to be USB-ID (as commonly thought to be "active-low" in the cable for USB host mode) makes no sense (see related thread http://forum.xda-developers.com/showthread.php?p=56896393), unless pin 24 is really the NEGATION of USB-ID. Using USBHostSwitcher.apk to place the Nook in USB host mode (with the HDTV adapter inserted) causes pin 24 to go from TTL-low (.92v) to TTL-high (3.3v), and also causes pin 1 (USB VBUS) to be powered to 5v. Edit: However, USB host mode still doesn't work through the HDTV adapter (see edit comments below).

Here is an image of the top of the adapter, with the Nook-edge connector down, and the pins on it numbered left to right 29, 27, ..., 3, 1. The cable-edge connector is up, and the pins on it are numbered left to right 30, 29, ..., 3, 2, 1 (high-res image here):

Here is an image of the bottom of the adapter, with the Nook-edge connector down, and the pins on it numbered left to right 2, 4, ..., 28, 30 (high-res image here):

Edit #1: After further examination of the images (see link above) and measuring voltages, it's clear that when in USB host mode, the data pins (5 & 6) and ground (29 & 30) go straight through from the Nook edge of the adapter to the cable edge. The Nook also provides USB power on pins 1 & 2 (USB VBUS). However, that power never gets to the corresponding pins 1 & 2 on the cable connector edge of the adapter, because transistor Q4 stands in the way. Transistors Q6, Q7, and Q9 are used to switch transistor Q4 on or off, and I think pin 23 (Nook edge) plays a role in that.

Edit #2: What that last sentences means, I think, is that USB host mode with the HDTV/HDMI adapter may work without modification, if the Nook USB cable is connected to a powered hub. Verygreen's CM11 and USBHostSwitcher.apk will probably be needed.

Edit #3: Verygreen's CM11 (at least the 8/17 SDcard-bootable variant) includes (as a notification tile) the USBHostSwitcher.apk functionality.

 

[Xirss]

Hi all.
What pins are used in USB cable? Is there a pull-up/pull-down resistor on USB ID pin?

 

[DeanGibson]

Open collector circuit on USB-ID

Hi all.
What pins are used in USB cable? Is there a pull-up/pull-down resistor on USB ID pin?

1. Pins 1 & 2 (+5v), 5 (data in), 6 (data out), 29 & 30 (ground).
2. Since the circuit in the HDTV/HDMI adapter connected to pin 24 has no pull-up or pull-down resistors, it is an "open collector" driver, and thus there would be a pull-up resistor in the Nook on pin 24.