Thank you for such explanation.

But I havnt attached anything on LCD_DATA.

I have four connection. 
1)GND(pin1)
2)Vcc(pin 3)
3)SCL(pin 17)-I have pulled up internally
4)SDA(pin 18)-I have pulled up internally

and my BBB is not powering on!!!!

As per your suggession how I use pull up resister for scl and sda pin, 
which I have pulled up internally (from device tree).   

Regards 
Jay Kothari


On Thursday, 15 January 2015 11:55:51 UTC+5:30, john3909 wrote:
>
>
> From: JAY KOTHARI <[email protected] <javascript:>>
> Reply-To: "[email protected] <javascript:>" <
> [email protected] <javascript:>>
> Date: Wednesday, January 14, 2015 at 9:56 PM
> To: "[email protected] <javascript:>" <[email protected] 
> <javascript:>>
> Subject: Re: [beagleboard] bmp085 with uext connection with BBB
>
> I belive that they may not provide required current. But would it cause by 
> BBB not to power on?  
>
> The pull up resistors will have nothing to do with BBB power up. My bet is 
> you have something connected to LCD_DATA[15..0] which changes the startup 
> mode of the BBB. Anything connected to these pins must be isolated until 
> after the SYS_RESETn goes high. Use a high impedance buffer to isolate 
> these signals and gate then with SYS_RESETn. 
>
> Regards,
> John
>
>
> I will connect external resistor with sda1 and scl1 pins of BBB which are 
> already pulled up. Where should I connect the other leg of these resistor.
>
> Regard 
> Jay Kothari
>
> On Thursday, 15 January 2015 11:21:22 UTC+5:30, john3909 wrote:
>>
>>
>> From: JAY KOTHARI <[email protected]>
>> Reply-To: "[email protected]" <[email protected]>
>> Date: Wednesday, January 14, 2015 at 9:17 PM
>> To: "[email protected]" <[email protected]>
>> Subject: Re: [beagleboard] bmp085 with uext connection with BBB
>>
>> bmp085 sensor works on 3.3v volt. I have internally pulled up the pin and 
>> I can see resistor connected in the harware diagram of bmp085. 
>> Still I connect external resistor?
>>
>> The internal resistors don’t provide enough current. You will still need 
>> external resistors and I suggest 4k7.
>>
>> Regards,
>> John
>>
>>
>>
>> On Thursday, 15 January 2015 09:56:46 UTC+5:30, liyaoshi wrote:
>>>
>>> Can you try connect with external 5V supply ?
>>> BTW, suggest R2 and R3 connect with 10k resister , 
>>>
>>>
>>> 2015-01-15 12:14 GMT+08:00 JAY KOTHARI <[email protected]>:
>>>
>>>> Hello,
>>>>       I am using bmp085 sensor with uext connection with beaglebone 
>>>> black. I have made change in device tree of BBB. I have made i2c1(pin 17 
>>>> and 18) as input pin and pulled up internally and set it to mode two. I 
>>>> have also set compatible property in device tree to load module of bmp085.
>>>>      After looking into hardware design manual of bmp085 I interface 
>>>> with beaglebone black.I connected four wire 
>>>> (vdd(pin3),gnd(pin1),sda(pin17) 
>>>> and scl(pin18)) and kept other unconnected.
>>>>
>>>>
>>>> https://www.olimex.com/Products/Modules/Sensors/MOD-BMP085/resources/MOD-BMP085_sch.pdf
>>>>
>>>>    When I boot my kernel my bmp085 module is loaded automatically and I 
>>>> am getting entry in /dev of i2c1
>>>>
>>>>     Problem:
>>>>     When I connect BBB with bmp085 my kernel hangs or BBB does not 
>>>> start at all!!!!What may be the problem???? 
>>>>    Note:  
>>>>    I am not using 5v supply.  
>>>>      
>>>>
>>>> -- 
>>>> For more options, visit http://beagleboard.org/discuss
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>>>
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