The GPIO pins on most processors, are open inputs until configured. So a weak pull up resistor to +3.3V (not the switched +3.3V) on the TX line between the Sitara pin and the MAX3232 input would likely fix your problem. Once configured, the TX line will overpower the weak pull up resistor.
--- Graham == On Tuesday, April 7, 2015 at 11:31:47 AM UTC-5, [email protected] wrote: > > I have a MAX3232 connected to UART5 on a BBB. During power up; presumably > before the dtb has been loaded to set the pinmux for the UART, I see a > "break" sequence being sent. A break sequence is defined as "tx held low > for a duration longer than 1 frame". > > Seems like pinmuxing won't help because it occurs too late. According to > the am335x data sheet the "zero state" for the corresponding pin is Z which > presumably means the pin will be low (i.e. "emitting" 0's) until the pinmux > takes over and configures it as a UART pin which presumably brings it to > idle (high). > > Any ideas how to avoid this? > > Thanks, > > > -W > -- 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 [email protected]. For more options, visit https://groups.google.com/d/optout.
