Re: [beagleboard] Need 16 GPIOs Next to each other on P8
Provided, you don't interfere with their settings during power up as they are also the boot pins. He's saying you shouldn't interfere with their state at boot. No driving, pullup, or pull down on any of these pins (besides the those that configure the sysboot setting on the board). Relays wont flip, but there are 100k pullups on some of the pins, so they could be in a state you don't want. You could isolate these pins with something like a bilateral switch (or a Va = Vb type unidirectional level shifter) during boot. Attach the enable to 3v3_exp, and make sure whatever is on the world side of the isolator is in a known state when the pins are at high impedance (using pull ups or down). For any pins that you want to switch simultaneously (which requires memory writes), make sure they're in the same gpio bank. -Brandon On Sunday, March 2, 2014 2:04:25 PM UTC-8, Gerald wrote: As is indicated in the System Reference Manual, you can use the LCD pins as GPIO pins. Provided, you don't interfere with their settings during power up as they are also the boot pins. Gerald On Sun, Mar 2, 2014 at 1:32 PM, mharr...@gmail.com javascript: wrote: Hi, I would like to configure BBB P8 with 16 (2 rows of 8) GPIO pins next to each other. They just need to be able to be set to high or low. I see P7 through P18 but I need 4 more. I am not using any LCD screen. Is it possible to reconfigure the pins? I am a BBB newbie and would appreciate any help so I don't mess anything up. Thanks -- 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/groups/opt_out. -- 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/groups/opt_out.
Re: [beagleboard] Need 16 GPIOs Next to each other on P8
When reconfigured, would the LCD pins change states during boot up? For example, if I had relays attached, would the pins open and close the relays during boot? Thanks On Sunday, March 2, 2014 5:04:25 PM UTC-5, Gerald wrote: As is indicated in the System Reference Manual, you can use the LCD pins as GPIO pins. Provided, you don't interfere with their settings during power up as they are also the boot pins. Gerald On Sun, Mar 2, 2014 at 1:32 PM, mharr...@gmail.com javascript: wrote: Hi, I would like to configure BBB P8 with 16 (2 rows of 8) GPIO pins next to each other. They just need to be able to be set to high or low. I see P7 through P18 but I need 4 more. I am not using any LCD screen. Is it possible to reconfigure the pins? I am a BBB newbie and would appreciate any help so I don't mess anything up. Thanks -- 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/groups/opt_out. -- 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/groups/opt_out.
Re: [beagleboard] Need 16 GPIOs Next to each other on P8
From: mharris...@gmail.com Reply-To: beagleboard@googlegroups.com Date: Tuesday, March 4, 2014 at 12:20 PM To: beagleboard@googlegroups.com Subject: Re: [beagleboard] Need 16 GPIOs Next to each other on P8 When reconfigured, would the LCD pins change states during boot up? For example, if I had relays attached, would the pins open and close the relays during boot? Don¹t load the HDMI device tree overlay and then all GPIO remain in their reset state which means all GPIO are defined as an input. Regards, John Thanks On Sunday, March 2, 2014 5:04:25 PM UTC-5, Gerald wrote: As is indicated in the System Reference Manual, you can use the LCD pins as GPIO pins. Provided, you don't interfere with their settings during power up as they are also the boot pins. Gerald On Sun, Mar 2, 2014 at 1:32 PM, mharr...@gmail.com javascript: wrote: Hi, I would like to configure BBB P8 with 16 (2 rows of 8) GPIO pins next to each other. They just need to be able to be set to high or low. I see P7 through P18 but I need 4 more. I am not using any LCD screen. Is it possible to reconfigure the pins? I am a BBB newbie and would appreciate any help so I don't mess anything up. Thanks -- 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/groups/opt_out. -- 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/groups/opt_out. -- 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/groups/opt_out.
Re: [beagleboard] Need 16 GPIOs Next to each other on P8
As is indicated in the System Reference Manual, you can use the LCD pins as GPIO pins. Provided, you don't interfere with their settings during power up as they are also the boot pins. Gerald On Sun, Mar 2, 2014 at 1:32 PM, mharris...@gmail.com wrote: Hi, I would like to configure BBB P8 with 16 (2 rows of 8) GPIO pins next to each other. They just need to be able to be set to high or low. I see P7 through P18 but I need 4 more. I am not using any LCD screen. Is it possible to reconfigure the pins? I am a BBB newbie and would appreciate any help so I don't mess anything up. Thanks -- 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/groups/opt_out. -- 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/groups/opt_out.
