From: JAY KOTHARI <jaikothar...@gmail.com> Reply-To: "beagleboard@googlegroups.com" <beagleboard@googlegroups.com> Date: Wednesday, January 14, 2015 at 9:56 PM To: "beagleboard@googlegroups.com" <beagleboard@googlegroups.com> 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 <jaikot...@gmail.com <javascript:> > >> Reply-To: "beagl...@googlegroups.com <javascript:> " >> <beagl...@googlegroups.com <javascript:> > >> Date: Wednesday, January 14, 2015 at 9:17 PM >> To: "beagl...@googlegroups.com <javascript:> " <beagl...@googlegroups.com >> <javascript:> > >> 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 don¹t 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 <jaikot...@gmail.com>: >>>>> 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-B >>>>> MP085_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 >>>>> --- >>>>> You received this message because you are subscribed to the Google Groups >>>>> "BeagleBoard" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send an >>>>> email to beagleboard...@googlegroups.com. >>>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >>> For more options, visit http://beagleboard.org/discuss >>> --- >>> You received this message because you are subscribed to the Google Groups >>> "BeagleBoard" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to beagleboard...@googlegroups.com <javascript:> . >>> For more options, visit https://groups.google.com/d/optout. > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
