I THINK with the 8250 driver and the beaglebone/board images, 6 UART's show up in the /dev/ directory as /dev/ttyS0... /dev/ttyS5 by default, but that doesn't mean that all of those 6 UARTs are enabled. You have to explicitly enable them. For instance, if you login as root and start poking around in /sys/class/tty/ttyS*, you'll see that some of the UARTs have an irq of 0, which I think is a sign that they're disabled.
On Tuesday, December 12, 2017 at 8:55:05 AM UTC-6, [email protected] wrote: > > Hello, > > I have a problem with UART on BeagleBone Black. I succeeded to enable > UART1 but UART2 asked me a problem and I can do anything on this port. > I'm on : Linux beaglebone 4.4.91-ti-r133 > I activated firmware with this : (on /boot/uEnv.txt) > ###Overide capes with eeprom > uboot_overlay_addr0=/lib/firmware/BB-UART1-00A0.dtbo > uboot_overlay_addr1=/lib/firmware/BB-UART2-00A0.dtbo > ... > > and activated everything I needed (all uart and 1 I2C) a little lower in > the same file : > ##Example v4.1.x > cape_disable=bone_capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN > > cape_enable=bone_capemgr.enable_partno=BB-I2C1,BB-UART4,BB-UART2,BB-UART5,BB-UART3,BB-UART1 > > Others UART have the same problem... > I have also this : debian@beaglebone:/boot$ ls -l /dev/ttyS* > crw--w---- 1 root tty 4, 64 Dec 12 15:23 /dev/ttyS0 > crw-rw---- 1 root dialout 4, 65 Dec 12 15:36 /dev/ttyS1 > crw-rw---- 1 root dialout 4, 66 Dec 12 15:34 /dev/ttyS2 > crw-rw---- 1 root dialout 4, 67 Dec 12 15:23 /dev/ttyS3 > crw-rw---- 1 root dialout 4, 68 Dec 12 15:23 /dev/ttyS4 > crw-rw---- 1 root dialout 4, 69 Dec 12 15:23 /dev/ttyS5 > > Then all the UART are activated right? > > But I can't communicate with my device.... and it's work with UART1... Do > you have a solution? > > 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/d3356848-53ba-46c8-8ce2-c1cd61db7f45%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
