I have a sensor hooked up to UART1. This seems to work just fine using cape-universal and config-pin to setup P9-24 and P9-26 in uart mode.
When I modify uEnv.txt to use BB-UART1 overlay, I am unable to read data from the sensor. Relevant portions of uEnv.txt looks like this: # Don't enable cape-universal cmdline=coherent_pool=1M quiet # Enable UART1 and I2C1 overlays cape_enable=bone_capemgr.enable_partno=BB-I2C1,BB-UART1 And I have commented out the original cmdline: #cmdline=coherent_pool=1M quiet cape_universal=enable Slots look like this: 0: PF---- -1 1: PF---- -1 2: PF---- -1 3: PF---- -1 4: P-O-L- 0 Override Board Name,00A0,Override Manuf,BB-I2C1 5: P-O-L- 1 Override Board Name,00A0,Override Manuf,BB-UART1 Kernel and rootfs: debian@bbb2:~$ uname -r 4.1.16-ti-rt-r44 debian@bbb2:~$ cat /etc/dogtag BeagleBoard.org Debian Image 2016-01-17 I have also pulled the latest bb.org-overlays and run install.sh. I have this working on another system with 4.1.13-ti-r35 with the 2015-11-09 rootfs. If I am correct in analyzing the BB-UART1 dtb that is working on this system, it appears as if P9_24 is configured with a pulldown resistor and P9_26 is configured with a pullup resistor. The BB-UART1 dtb on the system where this is not work (and the current version from bb.org-overlays) has no pullup/pulldown resistors configured for those pins. Looking at cape-universal (that works), it appears as if P9_24 and P9_26 are both configured with pullups. So, I'm assuming that this is why my current BB-UART1 setup is not working. Is the configuration of the current BB-UART1 (actually all of them) without pullup/pulldown for UART mode by design? If so, why? And of course, the converse question for cape-universal. Not being a H/W guy, maybe someone can inform me as to why my current BB-UART1 doesn't work and why these dtb's are thusly configured. ba -- 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.
