# Ideapad K1 DIY Host Cable [Pinout] (Help Needed) !



## Shaztech (Nov 4, 2011)

I'm tired of waiting for Lenovo host cable and that I cannot charge my tablet when I'm connected on the computer...
I want to add ports on the bottom like micro usb, standard dc connector and another one for usb host.
I know there space inside between the prop. connector and the right side. !

I'm compiling a Pinout but need someone that already have a host cable (some EU users receive one).
Please test each pin and post it here !!!
I will update a FULL pinout and pictures when completed

Update: The USB connector has every pins so I will use it !

*Left Pic: **TOP (Screen Side) * 
*Right Pic: BOTTOM*










01, 02, 33, 34: GND
07, 09, 11, 13, 28 : GND

17: +3V out when pin 30 grounded
18: +12V in (Charger)

04: Trigger Headphones when Grounded
30: Trigger USB Host ??? Output 3V on 17 when Grounded
31: Trigger USB Client (to PC) when Grounded

8, 10, 12, 14: Possibly Headphones Right, Left, Mic...

15: GND (Trigger ??)
20: GND(Trigger ??)

21: USB Client D-
23: USB Client D+
24: USB GND

There's no +5V out so maybe a trigger activate it !

Thanks for your help !


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## Shaztech (Nov 4, 2011)

I will try some combinations tonight !


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## wy13 (Feb 6, 2012)

Theory.

The connector is probably multi-use with solder connections based on use. From the looks of the printed circuit, pins 15, 20, and 31 are meant to be either soldered or unsoldered.

If pin 31 triggers usb client (and is currently grounding because that is a client cable), and grounding pin 30 triggers 3V on 17, perhaps pin 31 is keeping 17 from reaching 5V. Perhaps ungrounding 31, then grounding 30 will trigger host and give you 5V on 17 (can't have host and client at the same time)?


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## Shaztech (Nov 4, 2011)

wy13 said:


> Theory.
> 
> The connector is probably multi-use with solder connections based on use. From the looks of the printed circuit, pins 15, 20, and 31 are meant to be either soldered or unsoldered.
> 
> If pin 31 triggers usb client (and is currently grounding because that is a client cable), and grounding pin 30 triggers 3V on 17, perhaps pin 31 is keeping 17 from reaching 5V. Perhaps ungrounding 31, then grounding 30 will trigger host and give you 5V on 17 (can't have host and client at the same time)?


Already tried it, Pin 31 is currently "cut" so no GND on 31.


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## wy13 (Feb 6, 2012)

I wonder if the keyboard dock is actually using usb connections. My understanding is that the keyboard dock can be operated sans charger (it just won't be charging in use). If so, it may be possible that the keyboard is initiating the tablet into usb host mode. I don't know because I don't have a keyboard dock to test out.

By the way, does anyone know if the "proprietary" connector can be sourced from anywhere?


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## khf (Mar 18, 2012)

Shaztech said:


> I'm tired of waiting for Lenovo host cable and that I cannot charge my tablet when I'm connected on the computer...
> I want to add ports on the bottom like micro usb, standard dc connector and another one for usb host.
> I know there space inside between the prop. connector and the right side. !
> 
> ...


Hi
please if you obtain solution yet tell us.
thanks for topic.


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## khf (Mar 18, 2012)

Shaztech said:


> I'm tired of waiting for Lenovo host cable and that I cannot charge my tablet when I'm connected on the computer...
> I want to add ports on the bottom like micro usb, standard dc connector and another one for usb host.
> I know there space inside between the prop. connector and the right side. !
> 
> ...


menwhile, i found a site about cracked ideapad k1 opening
the chipset for usb is smsc 3315 .
you can find the datasheet for that.
http://www.techrepublic.com/blog/itdojo/lenovo-ideapad-k1-teardown-easy-to-open-not-so-easy-to-service/2894


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## gallahad2000 (Jan 4, 2012)

Cable available at lenovo for $12 + free shipping!
http://shop.lenovo.c..._menu_area=true

Also Provantage:http://www.provantage.com/YLEN92U2.htm
Macmall:http://www.macmall.c...171~pdp.haicccb
Alvio supposedly has it but can't find it, perhaps due to being out of stock
PSsuperstore:http://www.pcsuperst...vo-0B65411.html

Someone from the lenovo forums confirmed that the provantage cable works with their K1.

Source:http://forums.lenovo.../593525/page/38


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## olivierc (May 31, 2012)

Hi everyone I have looked at the spec USB chip smc USB3315, and also googled a lot about how does the OTG works.
And I came to the conclusion that grounding the ID pin of the USB3315 will activate OTG on K1. This what the datashee states:"ID pin of the USB cable. For non-OTG
applications this pin can be floated. For an A-Device ID is grounded. For a BDevice ID is floated."

Now the question is, which of all those pins is the ID pin ?
As soon as the ID pin is grounded I think that we will get the 5V on the VBUS pin which I think is the pin 24, labeled GND at the top of the post.

So the pin are
21: USB Client D-
23: USB Client D+
24: USB VBUS (+5V in OTG mode)

? : ID pin

If I find some extra time I will try to buy on ebay an extra USB data cable, and try to ground the unknown pin.
Or if Shaztech can try to ground pin 22, to see what happens....

Or if someone has bought the OTG cable and can measure the resitance between ground and all pins, we will apreciate a lot.
If pin is grounded the resitance should be 0.


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## olivierc (May 31, 2012)

Check this link
http://forum.xda-developers.com/showthread.php?t=1092493

Change the the micro USB B conector of the scheme by the 37 pin ideapad K1 conector.... If we knew where is the ID pin (sense pin) it should work.


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## Foxtrot_Xray (Dec 28, 2011)

olivierc said:


> Hi everyone I have looked at the spec USB chip smc USB3315, and also googled a lot about how does the OTG works.
> And I came to the conclusion that grounding the ID pin of the USB3315 will activate OTG on K1. This what the datashee states:"ID pin of the USB cable. For non-OTG
> applications this pin can be floated. For an A-Device ID is grounded. For a BDevice ID is floated."
> 
> ...


According to the device's datasheet, if it's the 24-pin SMD device, the ID pin in Pin #1. However, my pinouts do not match up with yout pins 21, 23, and 24.

See:
http://tec.icbuy.com...SMSC/3315db.pdf

If I have the wrong device, apologies.


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## olivierc (May 31, 2012)

Sorry for my bad english, but I was talking about the pin number of the photos of the first post, the one of the dock conector. What we have to find out is to which pin of the dock conector, the pin 1 of smd usb chip is connected to.


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## Foxtrot_Xray (Dec 28, 2011)

olivierc said:


> Sorry for my bad english, but I was talking about the pin number of the photos of the first post, the one of the dock conector. What we have to find out is to which pin of the dock conector, the pin 1 of smd usb chip is connected to.


Oh! Apologies, I misread.


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## fwfr.ls (Nov 10, 2011)

Hi, Maybe this will help. I dismantled my K1 keyboard after loading a few USB diagnostic tools and discovering that it appears to be USB based.
The whole thing is held together with glue-tape. The top of the keyboard clips on around the edges and from the 'velcro' sound, clips are around each key as well. Not sure it will go back together without additional adhesives. Oh well. Ask any questions -- I'm not gluing it back together until I get a hub inside.









1. front tablet connector. L-R (USB wires, 2 unknown, 2 red/black power)
2. same just not as close.



























4. circuit board adhesive taped to bottom of keyboard. 
CON1 - dock wire connector
J13 - wires to power the white LED for CAPS LOCK
J14 - wires to keyboard

5. Hey, these are those wires for those connectors. QUICK NOTE: those black bits at the right of the picture are broken bits that held the top of the keyboard facia on. If you really want to open your keyboard, DO NOT pry off the top of the key facia. The bottom of the keyboard is held together with sticky tape, really strong sticky tape, but you can separate it. The base of the keyboard has wires that could be ripped in the prying. All mileage will vary, you have been warned.


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## alexsnow (Aug 10, 2012)

fwfr.ls. Please, post the bottom side of k1 connector, bottom side of pcb board and nominal R13 resistor.


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## fwfr.ls (Nov 10, 2011)

Hello alexsnow, hope this helps.

The R13 does not have markings. Probably a "0".
As for the bottom image of the K1 mount board. There is nothing there except pins through the board. no tracings. All tracings are what you see.

I did a little more testing one weekend before deciding that something more is needed besides just hooking up wires in the right order. The pin number used in the below diagram are from the circuit board and k1 mount. Not my own.










As per the keyboard dock 
The P## are the larger sized pins; 8 in all. The S## are the tiny pins, 24 in all. The front pins are odd numbers and the back are even. Need to go buy some solid core wire to continue. ttfn.
The circuit board at the base of the connector has 4 wires coming off to the keyboard circuit board. Following the numbers theres #1: 5+V, #2: D+, #3: D-, #4: GND, #5: unused. What I can tell you is without resisters, there is barely enough juice coming from the K1 table along pings S04 and S24 to light a led, very dim. I suspect that the keyboard or any other device connected is designed to pull extra juice from P08 and create the full 5+ USB.

Did get one of those squid USB hubs from the local store, plenty of room to place the hub in the space behind the K1 mount and let the squid legs hang out on the side. The adapter is probably a plus to have or the battery will be drained quickly.

I really appreciate getting the ICS upgrade to the K1 from Khanning. Thank you


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## alexsnow (Aug 10, 2012)

Hello fwfr.ls. You are wrong. R13 is otg ID pullup resistor. P06 (blue)- +5v. S04 - otg ID pin. Pins D- D+ for the host and for the client are same. I connected id pin 68 kohm to GND and +5v appeared at one second and off. It works as a host (without +5v supply) if id pin unconnected. It works as a client if id pin connected to gnd. Interested near r13 via to the bottom side. where it is connected to. Intresting link http://4pda.ru/forum...=189536&st=2680


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## mjb32803 (Nov 29, 2011)

alexsnow said:


> Hello fwfr.ls. You are wrong. R13 is otg ID pullup resistor. P06 (blue)- +5v. S04 - otg ID pin. Pins D- D+ for the host and for the client are same. I connected id pin 68 kohm to GND and +5v appeared at one second and off. It works as a host (without +5v supply) if id pin unconnected. It works as a client if id pin connected to gnd. Interested near r13 via to the bottom side. where it is connected to. Intresting link http://4pda.ru/forum...=189536&st=2680


I went to that website and there is are two pictures that show a home made USB host/client switchable cable. The text next to the picture reads (compliments of google translate):

"The two thin white wires - switching USB host-client, when they are closed - USB client, are open - USB host. Two thick white wires - 12 for charging the tablet, do not have to always carry a charge, +12 V is at work and in the car, the USB does not have any relation. +5 V for USB comes from the tablet, and the key, which gives a voltage at pin terminal had opened "by hand", because has not yet figured out how it appears when you connect the "native" adapter. It is for this it is necessary to disassemble the tablet."

The problem I have is that I cannot seem to download the higher resolution photos to see HOW the two small white wires are connected? It seems they are very simple. If you have a way to post the pictures or can describe how the wires are connected that would be great.


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## alexsnow (Aug 10, 2012)

First post pins 19 - +5v host ; white - D-; Green D+; Next cable - gnd client; 31 - id pin; Cut the via near pin 31 from gnd and left unconnected. Short the +5v control switch inside tablet or correctly connect id pin. Waiting from fwfr.ls the bottom side of pcb board.


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## mjb32803 (Nov 29, 2011)

alexsnow said:


> First post pins 19 - +5v host ; white - D-; Green D+; Next cable - +5v client; 31 - id pin; Cut the via near pin 31 from gnd and left unconnected. Short the +5v control switch inside tablet or correctly connect id pin. Waiting from fwfr.ls the bottom side of pcb board.


I used a needle and cut the circuit board trace from pin 31 (S4). Does pin 31 connect to ground through the hole that goes to the other side of the circuit board? 
If I use a powered USB hub, I should not need +5 volt from the tablet.
How do I correctly connect the id pin (pin 31 yes?)
Is cutting pin 31 from ground all you need to do to activate usb host mode?


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## mjb32803 (Nov 29, 2011)

Shaztech said:


> I'm tired of waiting for Lenovo host cable and that I cannot charge my tablet when I'm connected on the computer...
> I want to add ports on the bottom like micro usb, standard dc connector and another one for usb host.
> I know there space inside between the prop. connector and the right side. !
> 
> ...


I have an after market USB data cable that does NOT ground pin 1. So far I have UN grounded pins 15, 20 and 30. These were the only ones that were grounded. All the connector pins are "floating" except for D+, D-, Data GND, and SHIELD GND.

Someone with a HOST cable... when you initially plug in the cable, do you get any message on the display? When I plug a host cable into my SGS3, I get a short popup that says "USB connector connected". Am just wondering if I should see the same type message on the tablet if the cable is configured correctly?


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## midnightrush (May 7, 2014)

Yup its now 2014 and im not sure anyone would still be interested in this anymore.

but who cares what anyone thinks....

For all of you that would like to build your own otg cable for the K1 i have attached an image of the official cable.

Sadly for some reason it doesnt work on my tablet :-( Ive also updated my K1 to K1_A301_21_03_120607 and running 4.0.3.

when i plug to my pc it works...but when i plug the otg nothing happens... tried a keyboard.... tried a usb key.... xbox 360 remote... nothing!

So for all of you who were once interested to get this cable, here is an image of the pinout!

Good luck!

https://www.dropbox.com/s/v8612v75d705v22/20140506_211340.jpg

https://dl.dropboxusercontent.com/u/11602860/20140506_230203.jpg


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## mjb32803 (Nov 29, 2011)

Thanks midnightrush.... I still use my K1 and appreciate you posting those photos. Going to try and replicate the cable.


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